AyeCode / invoicing

includes/class-wpinv-ajax.php

Spacing +364 added lines, -364 removed lines

@@ -7,28 +7,28 @@ 
  */
  
 // MUST have WordPress.
-if ( !defined( 'WPINC' ) ) {
-    exit( 'Do NOT access this file directly: ' . basename( __FILE__ ) );
+if (!defined('WPINC')) {
+    exit('Do NOT access this file directly: ' . basename(__FILE__));
 }
 
 class WPInv_Ajax {
     public static function init() {
-        add_action( 'init', array( __CLASS__, 'define_ajax' ), 0 );
-        add_action( 'template_redirect', array( __CLASS__, 'do_wpinv_ajax' ), 0 );
+        add_action('init', array(__CLASS__, 'define_ajax'), 0);
+        add_action('template_redirect', array(__CLASS__, 'do_wpinv_ajax'), 0);
         self::add_ajax_events();
     }
 
     public static function define_ajax() {
-        if ( !empty( $_GET['wpinv-ajax'] ) ) {
-            if ( ! defined( 'DOING_AJAX' ) ) {
-                define( 'DOING_AJAX', true );
+        if (!empty($_GET['wpinv-ajax'])) {
+            if (!defined('DOING_AJAX')) {
+                define('DOING_AJAX', true);
             }
-            if ( ! defined( 'WC_DOING_AJAX' ) ) {
-                define( 'WC_DOING_AJAX', true );
+            if (!defined('WC_DOING_AJAX')) {
+                define('WC_DOING_AJAX', true);
             }
             // Turn off display_errors during AJAX events to prevent malformed JSON
-            if ( ! WP_DEBUG || ( WP_DEBUG && ! WP_DEBUG_DISPLAY ) ) {
-                /** @scrutinizer ignore-unhandled */ @ini_set( 'display_errors', 0 );
+            if (!WP_DEBUG || (WP_DEBUG && !WP_DEBUG_DISPLAY)) {
+                /** @scrutinizer ignore-unhandled */ @ini_set('display_errors', 0);
             }
             $GLOBALS['wpdb']->hide_errors();
         }
@@ -37,24 +37,24 @@ 
     public static function do_wpinv_ajax() {
         global $wp_query;
 
-        if ( !empty( $_GET['wpinv-ajax'] ) ) {
-            $wp_query->set( 'wpinv-ajax', sanitize_text_field( $_GET['wpinv-ajax'] ) );
+        if (!empty($_GET['wpinv-ajax'])) {
+            $wp_query->set('wpinv-ajax', sanitize_text_field($_GET['wpinv-ajax']));
         }
 
-        if ( $action = $wp_query->get( 'wpinv-ajax' ) ) {
+        if ($action = $wp_query->get('wpinv-ajax')) {
             self::wpinv_ajax_headers();
-            do_action( 'wpinv_ajax_' . sanitize_text_field( $action ) );
+            do_action('wpinv_ajax_' . sanitize_text_field($action));
             die();
         }
     }
     
     private static function wpinv_ajax_headers() {
         send_origin_headers();
-        /** @scrutinizer ignore-unhandled */ @header( 'Content-Type: text/html; charset=' . get_option( 'blog_charset' ) );
-        /** @scrutinizer ignore-unhandled */ @header( 'X-Robots-Tag: noindex' );
+        /** @scrutinizer ignore-unhandled */ @header('Content-Type: text/html; charset=' . get_option('blog_charset'));
+        /** @scrutinizer ignore-unhandled */ @header('X-Robots-Tag: noindex');
         send_nosniff_header();
         nocache_headers();
-        status_header( 200 );
+        status_header(200);
     }
     
     public static function add_ajax_events() {
@@ -80,39 +80,39 @@ 
             'buy_items' => true,
         );
 
-        foreach ( $ajax_events as $ajax_event => $nopriv ) {
-            add_action( 'wp_ajax_wpinv_' . $ajax_event, array( __CLASS__, $ajax_event ) );
+        foreach ($ajax_events as $ajax_event => $nopriv) {
+            add_action('wp_ajax_wpinv_' . $ajax_event, array(__CLASS__, $ajax_event));
             
-            if ( !defined( 'WPI_AJAX_' . strtoupper( $nopriv ) ) ) {
-                define( 'WPI_AJAX_' . strtoupper( $nopriv ), 1 );
+            if (!defined('WPI_AJAX_' . strtoupper($nopriv))) {
+                define('WPI_AJAX_' . strtoupper($nopriv), 1);
             }
 
-            if ( $nopriv ) {
-                add_action( 'wp_ajax_nopriv_wpinv_' . $ajax_event, array( __CLASS__, $ajax_event ) );
+            if ($nopriv) {
+                add_action('wp_ajax_nopriv_wpinv_' . $ajax_event, array(__CLASS__, $ajax_event));
 
-                add_action( 'wpinv_ajax_' . $ajax_event, array( __CLASS__, $ajax_event ) );
+                add_action('wpinv_ajax_' . $ajax_event, array(__CLASS__, $ajax_event));
             }
         }
     }
     
     public static function add_note() {
-        check_ajax_referer( 'add-invoice-note', '_nonce' );
+        check_ajax_referer('add-invoice-note', '_nonce');
 
-        if ( ! wpinv_current_user_can_manage_invoicing() ) {
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
 
-        $post_id   = absint( $_POST['post_id'] );
-        $note      = wp_kses_post( trim( stripslashes( $_POST['note'] ) ) );
-        $note_type = sanitize_text_field( $_POST['note_type'] );
+        $post_id   = absint($_POST['post_id']);
+        $note      = wp_kses_post(trim(stripslashes($_POST['note'])));
+        $note_type = sanitize_text_field($_POST['note_type']);
 
         $is_customer_note = $note_type == 'customer' ? 1 : 0;
 
-        if ( $post_id > 0 ) {
-            $note_id = wpinv_insert_payment_note( $post_id, $note, $is_customer_note );
+        if ($post_id > 0) {
+            $note_id = wpinv_insert_payment_note($post_id, $note, $is_customer_note);
 
-            if ( $note_id > 0 && !is_wp_error( $note_id ) ) {
-                wpinv_get_invoice_note_line_item( $note_id );
+            if ($note_id > 0 && !is_wp_error($note_id)) {
+                wpinv_get_invoice_note_line_item($note_id);
             }
         }
 
@@ -120,16 +120,16 @@ 
     }
 
     public static function delete_note() {
-        check_ajax_referer( 'delete-invoice-note', '_nonce' );
+        check_ajax_referer('delete-invoice-note', '_nonce');
 
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
 
-        $note_id = (int)$_POST['note_id'];
+        $note_id = (int) $_POST['note_id'];
 
-        if ( $note_id > 0 ) {
-            wp_delete_comment( $note_id, true );
+        if ($note_id > 0) {
+            wp_delete_comment($note_id, true);
         }
 
         die();
@@ -142,8 +142,8 @@ 
     }
     
     public static function checkout() {
-        if ( ! defined( 'WPINV_CHECKOUT' ) ) {
-            define( 'WPINV_CHECKOUT', true );
+        if (!defined('WPINV_CHECKOUT')) {
+            define('WPINV_CHECKOUT', true);
         }
 
         wpinv_process_checkout();
@@ -152,53 +152,53 @@ 
     
     public static function add_invoice_item() {
         global $wpi_userID, $wpinv_ip_address_country;
-        check_ajax_referer( 'invoice-item', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('invoice-item', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $item_id    = sanitize_text_field( $_POST['item_id'] );
-        $invoice_id = absint( $_POST['invoice_id'] );
+        $item_id    = sanitize_text_field($_POST['item_id']);
+        $invoice_id = absint($_POST['invoice_id']);
         
-        if ( !is_numeric( $invoice_id ) || !is_numeric( $item_id ) ) {
+        if (!is_numeric($invoice_id) || !is_numeric($item_id)) {
             die();
         }
         
-        $invoice    = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) ) {
+        $invoice = wpinv_get_invoice($invoice_id);
+        if (empty($invoice)) {
             die();
         }
         
-        if ( $invoice->is_paid() || $invoice->is_refunded() ) {
+        if ($invoice->is_paid() || $invoice->is_refunded()) {
             die(); // Don't allow modify items for paid invoice.
         }
         
-        if ( !empty( $_POST['user_id'] ) ) {
-            $wpi_userID = absint( $_POST['user_id'] ); 
+        if (!empty($_POST['user_id'])) {
+            $wpi_userID = absint($_POST['user_id']); 
         }
 
-        $item = new WPInv_Item( $item_id );
-        if ( !( !empty( $item ) && $item->post_type == 'wpi_item' ) ) {
+        $item = new WPInv_Item($item_id);
+        if (!(!empty($item) && $item->post_type == 'wpi_item')) {
             die();
         }
         
         // Validate item before adding to invoice because recurring item must be paid individually.
-        if ( !empty( $invoice->cart_details ) ) {
+        if (!empty($invoice->cart_details)) {
             $valid = true;
             
-            if ( $recurring_item = $invoice->get_recurring() ) {
-                if ( $recurring_item != $item_id ) {
+            if ($recurring_item = $invoice->get_recurring()) {
+                if ($recurring_item != $item_id) {
                     $valid = false;
                 }
-            } else if ( wpinv_is_recurring_item( $item_id ) ) {
+            } else if (wpinv_is_recurring_item($item_id)) {
                 $valid = false;
             }
             
-            if ( !$valid ) {
+            if (!$valid) {
                 $response               = array();
                 $response['success']    = false;
-                $response['msg']        = __( 'You can not add item because recurring item must be paid individually!', 'invoicing' );
-                wp_send_json( $response );
+                $response['msg']        = __('You can not add item because recurring item must be paid individually!', 'invoicing');
+                wp_send_json($response);
             }
         }
         
@@ -206,11 +206,11 @@ 
         
         $data                   = array();
         $data['invoice_id']     = $invoice_id;
-        $data['cart_discounts'] = $invoice->get_discounts( true );
+        $data['cart_discounts'] = $invoice->get_discounts(true);
         
-        wpinv_set_checkout_session( $data );
+        wpinv_set_checkout_session($data);
         
-        $quantity = wpinv_item_quantities_enabled() && !empty($_POST['qty']) && (int)$_POST['qty'] > 0 ? (int)$_POST['qty'] : 1;
+        $quantity = wpinv_item_quantities_enabled() && !empty($_POST['qty']) && (int) $_POST['qty'] > 0 ? (int) $_POST['qty'] : 1;
 
         $args = array(
             'id'            => $item_id,
@@ -223,21 +223,21 @@ 
             'fees'          => array()
         );
 
-        $invoice->add_item( $item_id, $args );
+        $invoice->add_item($item_id, $args);
         $invoice->save();
         
-        if ( empty( $_POST['country'] ) ) {
+        if (empty($_POST['country'])) {
             $_POST['country'] = !empty($invoice->country) ? $invoice->country : wpinv_get_default_country();
         }
-        if ( empty( $_POST['state'] ) ) {
+        if (empty($_POST['state'])) {
             $_POST['state'] = $invoice->state;
         }
          
-        $invoice->country   = sanitize_text_field( $_POST['country'] );
-        $invoice->state     = sanitize_text_field( $_POST['state'] );
+        $invoice->country   = sanitize_text_field($_POST['country']);
+        $invoice->state     = sanitize_text_field($_POST['state']);
         
-        $invoice->set( 'country', sanitize_text_field( $_POST['country'] ) );
-        $invoice->set( 'state', sanitize_text_field( $_POST['state'] ) );
+        $invoice->set('country', sanitize_text_field($_POST['country']));
+        $invoice->set('state', sanitize_text_field($_POST['state']));
         
         $wpinv_ip_address_country = $invoice->country;
 
@@ -245,7 +245,7 @@ 
         
         $response                       = array();
         $response['success']            = true;
-        $response['data']['items']      = wpinv_admin_get_line_items( $invoice );
+        $response['data']['items']      = wpinv_admin_get_line_items($invoice);
         $response['data']['subtotal']   = $invoice->get_subtotal();
         $response['data']['subtotalf']  = $invoice->get_subtotal(true);
         $response['data']['tax']        = $invoice->get_tax();
@@ -257,41 +257,41 @@ 
         
         wpinv_set_checkout_session($checkout_session);
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
 
 
     public static function remove_invoice_item() {
         global $wpi_userID, $wpinv_ip_address_country;
         
-        check_ajax_referer( 'invoice-item', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('invoice-item', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $item_id    = sanitize_text_field( $_POST['item_id'] );
-        $invoice_id = absint( $_POST['invoice_id'] );
-        $cart_index = isset( $_POST['index'] ) && $_POST['index'] >= 0 ? $_POST['index'] : false;
+        $item_id    = sanitize_text_field($_POST['item_id']);
+        $invoice_id = absint($_POST['invoice_id']);
+        $cart_index = isset($_POST['index']) && $_POST['index'] >= 0 ? $_POST['index'] : false;
         
-        if ( !is_numeric( $invoice_id ) || !is_numeric( $item_id ) ) {
+        if (!is_numeric($invoice_id) || !is_numeric($item_id)) {
             die();
         }
 
-        $invoice    = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) ) {
+        $invoice = wpinv_get_invoice($invoice_id);
+        if (empty($invoice)) {
             die();
         }
         
-        if ( $invoice->is_paid() || $invoice->is_refunded() ) {
+        if ($invoice->is_paid() || $invoice->is_refunded()) {
             die(); // Don't allow modify items for paid invoice.
         }
         
-        if ( !empty( $_POST['user_id'] ) ) {
-            $wpi_userID = absint( $_POST['user_id'] ); 
+        if (!empty($_POST['user_id'])) {
+            $wpi_userID = absint($_POST['user_id']); 
         }
 
-        $item       = new WPInv_Item( $item_id );
-        if ( !( !empty( $item ) && $item->post_type == 'wpi_item' ) ) {
+        $item = new WPInv_Item($item_id);
+        if (!(!empty($item) && $item->post_type == 'wpi_item')) {
             die();
         }
         
@@ -299,9 +299,9 @@ 
         
         $data                   = array();
         $data['invoice_id']     = $invoice_id;
-        $data['cart_discounts'] = $invoice->get_discounts( true );
+        $data['cart_discounts'] = $invoice->get_discounts(true);
         
-        wpinv_set_checkout_session( $data );
+        wpinv_set_checkout_session($data);
 
         $args = array(
             'id'         => $item_id,
@@ -309,21 +309,21 @@ 
             'cart_index' => $cart_index
         );
 
-        $invoice->remove_item( $item_id, $args );
+        $invoice->remove_item($item_id, $args);
         $invoice->save();
         
-        if ( empty( $_POST['country'] ) ) {
+        if (empty($_POST['country'])) {
             $_POST['country'] = !empty($invoice->country) ? $invoice->country : wpinv_get_default_country();
         }
-        if ( empty( $_POST['state'] ) ) {
+        if (empty($_POST['state'])) {
             $_POST['state'] = $invoice->state;
         }
          
-        $invoice->country   = sanitize_text_field( $_POST['country'] );
-        $invoice->state     = sanitize_text_field( $_POST['state'] );
+        $invoice->country   = sanitize_text_field($_POST['country']);
+        $invoice->state     = sanitize_text_field($_POST['state']);
         
-        $invoice->set( 'country', sanitize_text_field( $_POST['country'] ) );
-        $invoice->set( 'state', sanitize_text_field( $_POST['state'] ) );
+        $invoice->set('country', sanitize_text_field($_POST['country']));
+        $invoice->set('state', sanitize_text_field($_POST['state']));
         
         $wpinv_ip_address_country = $invoice->country;
         
@@ -331,7 +331,7 @@ 
         
         $response                       = array();
         $response['success']            = true;
-        $response['data']['items']      = wpinv_admin_get_line_items( $invoice );
+        $response['data']['items']      = wpinv_admin_get_line_items($invoice);
         $response['data']['subtotal']   = $invoice->get_subtotal();
         $response['data']['subtotalf']  = $invoice->get_subtotal(true);
         $response['data']['tax']        = $invoice->get_tax();
@@ -343,55 +343,55 @@ 
         
         wpinv_set_checkout_session($checkout_session);
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function create_invoice_item() {
-        check_ajax_referer( 'invoice-item', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('invoice-item', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $invoice_id = absint( $_POST['invoice_id'] );
+        $invoice_id = absint($_POST['invoice_id']);
 
         // Find the item
-        if ( !is_numeric( $invoice_id ) ) {
+        if (!is_numeric($invoice_id)) {
             die();
         }        
         
-        $invoice     = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) ) {
+        $invoice = wpinv_get_invoice($invoice_id);
+        if (empty($invoice)) {
             die();
         }
         
         // Validate item before adding to invoice because recurring item must be paid individually.
-        if ( !empty( $invoice->cart_details ) && $invoice->get_recurring() ) {
+        if (!empty($invoice->cart_details) && $invoice->get_recurring()) {
             $response               = array();
             $response['success']    = false;
-            $response['msg']        = __( 'You can not add item because recurring item must be paid individually!', 'invoicing' );
-            wp_send_json( $response );
+            $response['msg']        = __('You can not add item because recurring item must be paid individually!', 'invoicing');
+            wp_send_json($response);
         }        
         
-        $save_item = wp_unslash( $_POST['_wpinv_quick'] );
+        $save_item = wp_unslash($_POST['_wpinv_quick']);
         
         $meta               = array();
         $meta['type']       = !empty($save_item['type']) ? sanitize_text_field($save_item['type']) : 'custom';
-        $meta['price']      = !empty($save_item['price']) ? wpinv_sanitize_amount( $save_item['price'] ) : 0;
+        $meta['price']      = !empty($save_item['price']) ? wpinv_sanitize_amount($save_item['price']) : 0;
         $meta['vat_rule']   = !empty($save_item['vat_rule']) ? sanitize_text_field($save_item['vat_rule']) : 'digital';
         $meta['vat_class']  = !empty($save_item['vat_class']) ? sanitize_text_field($save_item['vat_class']) : '_standard';
         
         $data                   = array();
         $data['post_title']     = sanitize_text_field($save_item['name']);
         $data['post_status']    = 'publish';
-        $data['post_excerpt']   = ! empty( $save_item['excerpt'] ) ? wp_kses_post( $save_item['excerpt'] ) : '';
+        $data['post_excerpt']   = !empty($save_item['excerpt']) ? wp_kses_post($save_item['excerpt']) : '';
         $data['meta']           = $meta;
         
         $item = new WPInv_Item();
-        $item->create( $data );
+        $item->create($data);
         
-        if ( !empty( $item ) ) {
+        if (!empty($item)) {
             $_POST['item_id']   = $item->ID;
-            $_POST['qty']       = !empty($save_item['qty']) && $save_item['qty'] > 0 ? (int)$save_item['qty'] : 1;
+            $_POST['qty']       = !empty($save_item['qty']) && $save_item['qty'] > 0 ? (int) $save_item['qty'] : 1;
             
             self::add_invoice_item();
         }
@@ -399,15 +399,15 @@ 
     }
     
     public static function get_billing_details() {
-        check_ajax_referer( 'get-billing-details', '_nonce' );
+        check_ajax_referer('get-billing-details', '_nonce');
         
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
 
-        $user_id            = (int)$_POST['user_id'];
+        $user_id            = (int) $_POST['user_id'];
         $billing_details    = wpinv_get_user_address($user_id);
-        $billing_details    = apply_filters( 'wpinv_fill_billing_details', $billing_details, $user_id );
+        $billing_details    = apply_filters('wpinv_fill_billing_details', $billing_details, $user_id);
         
         if (isset($billing_details['user_id'])) {
             unset($billing_details['user_id']);
@@ -421,20 +421,20 @@ 
         $response['success']                    = true;
         $response['data']['billing_details']    = $billing_details;
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function admin_recalculate_totals() {
         global $wpi_userID, $wpinv_ip_address_country;
         
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('wpinv-nonce', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $invoice_id = absint( $_POST['invoice_id'] );        
-        $invoice    = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) ) {
+        $invoice_id = absint($_POST['invoice_id']);        
+        $invoice    = wpinv_get_invoice($invoice_id);
+        if (empty($invoice)) {
             die();
         }
 
@@ -442,29 +442,29 @@ 
 
         $data                   = array();
         $data['invoice_id']     = $invoice_id;
-        $data['cart_discounts'] = $invoice->get_discounts( true );
+        $data['cart_discounts'] = $invoice->get_discounts(true);
 
-        wpinv_set_checkout_session( $data );
+        wpinv_set_checkout_session($data);
         
-        if ( !empty( $_POST['user_id'] ) ) {
-            $wpi_userID = absint( $_POST['user_id'] ); 
+        if (!empty($_POST['user_id'])) {
+            $wpi_userID = absint($_POST['user_id']); 
         }
         
-        if ( empty( $_POST['country'] ) ) {
+        if (empty($_POST['country'])) {
             $_POST['country'] = !empty($invoice->country) ? $invoice->country : wpinv_get_default_country();
         }
 
         $disable_taxes = 0;
-        if ( ! empty( $_POST['disable_taxes'] ) ) {
+        if (!empty($_POST['disable_taxes'])) {
             $disable_taxes = 1;
         }
-        $invoice->set( 'disable_taxes', $disable_taxes );
+        $invoice->set('disable_taxes', $disable_taxes);
 
-        $invoice->country = sanitize_text_field( $_POST['country'] );
-        $invoice->set( 'country', sanitize_text_field( $_POST['country'] ) );
-        if ( isset( $_POST['state'] ) ) {
-            $invoice->state = sanitize_text_field( $_POST['state'] );
-            $invoice->set( 'state', sanitize_text_field( $_POST['state'] ) );
+        $invoice->country = sanitize_text_field($_POST['country']);
+        $invoice->set('country', sanitize_text_field($_POST['country']));
+        if (isset($_POST['state'])) {
+            $invoice->state = sanitize_text_field($_POST['state']);
+            $invoice->set('state', sanitize_text_field($_POST['state']));
         }
         
         $wpinv_ip_address_country = $invoice->country;
@@ -473,7 +473,7 @@ 
         
         $response                       = array();
         $response['success']            = true;
-        $response['data']['items']      = wpinv_admin_get_line_items( $invoice );
+        $response['data']['items']      = wpinv_admin_get_line_items($invoice);
         $response['data']['subtotal']   = $invoice->get_subtotal();
         $response['data']['subtotalf']  = $invoice->get_subtotal(true);
         $response['data']['tax']        = $invoice->get_tax();
@@ -485,25 +485,25 @@ 
         
         wpinv_set_checkout_session($checkout_session);
 
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function admin_apply_discount() {
         global $wpi_userID;
         
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('wpinv-nonce', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $invoice_id = absint( $_POST['invoice_id'] );
-        $discount_code = sanitize_text_field( $_POST['code'] );
-        if ( empty( $invoice_id ) || empty( $discount_code ) ) {
+        $invoice_id = absint($_POST['invoice_id']);
+        $discount_code = sanitize_text_field($_POST['code']);
+        if (empty($invoice_id) || empty($discount_code)) {
             die();
         }
         
-        $invoice = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) || ( !empty( $invoice ) && ( $invoice->is_paid() || $invoice->is_refunded() ) ) ) {
+        $invoice = wpinv_get_invoice($invoice_id);
+        if (empty($invoice) || (!empty($invoice) && ($invoice->is_paid() || $invoice->is_refunded()))) {
             die();
         }
         
@@ -511,49 +511,49 @@ 
         
         $data                   = array();
         $data['invoice_id']     = $invoice_id;
-        $data['cart_discounts'] = $invoice->get_discounts( true );
+        $data['cart_discounts'] = $invoice->get_discounts(true);
         
-        wpinv_set_checkout_session( $data );
+        wpinv_set_checkout_session($data);
         
         $response               = array();
         $response['success']    = false;
-        $response['msg']        = __( 'This discount is invalid.', 'invoicing' );
+        $response['msg']        = __('This discount is invalid.', 'invoicing');
         $response['data']['code'] = $discount_code;
         
-        if ( wpinv_is_discount_valid( $discount_code, $invoice->get_user_id() ) ) {
-            $discounts = wpinv_set_cart_discount( $discount_code );
+        if (wpinv_is_discount_valid($discount_code, $invoice->get_user_id())) {
+            $discounts = wpinv_set_cart_discount($discount_code);
             
             $response['success'] = true;
-            $response['msg'] = __( 'Discount has been applied successfully.', 'invoicing' );
-        }  else {
+            $response['msg'] = __('Discount has been applied successfully.', 'invoicing');
+        } else {
             $errors = wpinv_get_errors();
-            if ( !empty( $errors['wpinv-discount-error'] ) ) {
+            if (!empty($errors['wpinv-discount-error'])) {
                 $response['msg'] = $errors['wpinv-discount-error'];
             }
-            wpinv_unset_error( 'wpinv-discount-error' );
+            wpinv_unset_error('wpinv-discount-error');
         }
         
         wpinv_set_checkout_session($checkout_session);
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function admin_remove_discount() {
         global $wpi_userID;
         
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('wpinv-nonce', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $invoice_id = absint( $_POST['invoice_id'] );
-        $discount_code = sanitize_text_field( $_POST['code'] );
-        if ( empty( $invoice_id ) || empty( $discount_code ) ) {
+        $invoice_id = absint($_POST['invoice_id']);
+        $discount_code = sanitize_text_field($_POST['code']);
+        if (empty($invoice_id) || empty($discount_code)) {
             die();
         }
         
-        $invoice = wpinv_get_invoice( $invoice_id );
-        if ( empty( $invoice ) || ( !empty( $invoice ) && ( $invoice->is_paid() || $invoice->is_refunded() ) ) ) {
+        $invoice = wpinv_get_invoice($invoice_id);
+        if (empty($invoice) || (!empty($invoice) && ($invoice->is_paid() || $invoice->is_refunded()))) {
             die();
         }
         
@@ -561,38 +561,38 @@ 
         
         $data                   = array();
         $data['invoice_id']     = $invoice_id;
-        $data['cart_discounts'] = $invoice->get_discounts( true );
+        $data['cart_discounts'] = $invoice->get_discounts(true);
         
-        wpinv_set_checkout_session( $data );
+        wpinv_set_checkout_session($data);
         
         $response               = array();
         $response['success']    = false;
         $response['msg']        = NULL;
         
-        $discounts  = wpinv_unset_cart_discount( $discount_code );
+        $discounts = wpinv_unset_cart_discount($discount_code);
         $response['success'] = true;
-        $response['msg'] = __( 'Discount has been removed successfully.', 'invoicing' );
+        $response['msg'] = __('Discount has been removed successfully.', 'invoicing');
         
         wpinv_set_checkout_session($checkout_session);
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function check_email() {
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('wpinv-nonce', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $email = sanitize_text_field( $_POST['email'] );
+        $email = sanitize_text_field($_POST['email']);
         
         $response = array();
-        if ( is_email( $email ) && email_exists( $email ) && $user_data = get_user_by( 'email', $email ) ) {
+        if (is_email($email) && email_exists($email) && $user_data = get_user_by('email', $email)) {
             $user_id            = $user_data->ID;
             $user_login         = $user_data->user_login;
             $display_name       = $user_data->display_name ? $user_data->display_name : $user_login;
             $billing_details    = wpinv_get_user_address($user_id);
-            $billing_details    = apply_filters( 'wpinv_fill_billing_details', $billing_details, $user_id );
+            $billing_details    = apply_filters('wpinv_fill_billing_details', $billing_details, $user_id);
             
             if (isset($billing_details['user_id'])) {
                 unset($billing_details['user_id']);
@@ -608,54 +608,54 @@ 
             $response['data']['billing_details']    = $billing_details;
         }
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function run_tool() {
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
-        if ( !wpinv_current_user_can_manage_invoicing() ) {
+        check_ajax_referer('wpinv-nonce', '_nonce');
+        if (!wpinv_current_user_can_manage_invoicing()) {
             die(-1);
         }
         
-        $tool = sanitize_text_field( $_POST['tool'] );
+        $tool = sanitize_text_field($_POST['tool']);
         
-        do_action( 'wpinv_run_tool' );
+        do_action('wpinv_run_tool');
         
-        if ( !empty( $tool ) ) {
-            do_action( 'wpinv_tool_' . $tool );
+        if (!empty($tool)) {
+            do_action('wpinv_tool_' . $tool);
         }
     }
     
     public static function apply_discount() {
         global $wpi_userID;
         
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
+        check_ajax_referer('wpinv-nonce', '_nonce');
         
         $response = array();
         
-        if ( isset( $_POST['code'] ) ) {
-            $discount_code = sanitize_text_field( $_POST['code'] );
+        if (isset($_POST['code'])) {
+            $discount_code = sanitize_text_field($_POST['code']);
 
             $response['success']        = false;
             $response['msg']            = '';
             $response['data']['code']   = $discount_code;
             
             $invoice = wpinv_get_invoice_cart();
-            if ( empty( $invoice->ID ) ) {
-                $response['msg'] = __( 'Invalid checkout request.', 'invoicing' );
-                wp_send_json( $response );
+            if (empty($invoice->ID)) {
+                $response['msg'] = __('Invalid checkout request.', 'invoicing');
+                wp_send_json($response);
             }
 
             $wpi_userID = $invoice->get_user_id();
 
-            if ( wpinv_is_discount_valid( $discount_code, $wpi_userID ) ) {
-                $discount       = wpinv_get_discount_by_code( $discount_code );
-                $discounts      = wpinv_set_cart_discount( $discount_code );
-                $amount         = wpinv_format_discount_rate( wpinv_get_discount_type( $discount->ID ), wpinv_get_discount_amount( $discount->ID ) );
-                $total          = wpinv_get_cart_total( null, $discounts );
-                $cart_totals    = wpinv_recalculate_tax( true );
+            if (wpinv_is_discount_valid($discount_code, $wpi_userID)) {
+                $discount       = wpinv_get_discount_by_code($discount_code);
+                $discounts      = wpinv_set_cart_discount($discount_code);
+                $amount         = wpinv_format_discount_rate(wpinv_get_discount_type($discount->ID), wpinv_get_discount_amount($discount->ID));
+                $total          = wpinv_get_cart_total(null, $discounts);
+                $cart_totals    = wpinv_recalculate_tax(true);
             
-                if ( !empty( $cart_totals ) ) {
+                if (!empty($cart_totals)) {
                     $response['success']        = true;
                     $response['data']           = $cart_totals;
                     $response['data']['code']   = $discount_code;
@@ -664,29 +664,29 @@ 
                 }
             } else {
                 $errors = wpinv_get_errors();
-                $response['msg']  = $errors['wpinv-discount-error'];
-                wpinv_unset_error( 'wpinv-discount-error' );
+                $response['msg'] = $errors['wpinv-discount-error'];
+                wpinv_unset_error('wpinv-discount-error');
             }
 
             // Allow for custom discount code handling
-            $response = apply_filters( 'wpinv_ajax_discount_response', $response );
+            $response = apply_filters('wpinv_ajax_discount_response', $response);
         }
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
     
     public static function remove_discount() {
-        check_ajax_referer( 'wpinv-nonce', '_nonce' );
+        check_ajax_referer('wpinv-nonce', '_nonce');
         
         $response = array();
         
-        if ( isset( $_POST['code'] ) ) {
-            $discount_code  = sanitize_text_field( $_POST['code'] );
-            $discounts      = wpinv_unset_cart_discount( $discount_code );
-            $total          = wpinv_get_cart_total( null, $discounts );
-            $cart_totals    = wpinv_recalculate_tax( true );
+        if (isset($_POST['code'])) {
+            $discount_code  = sanitize_text_field($_POST['code']);
+            $discounts      = wpinv_unset_cart_discount($discount_code);
+            $total          = wpinv_get_cart_total(null, $discounts);
+            $cart_totals    = wpinv_recalculate_tax(true);
             
-            if ( !empty( $cart_totals ) ) {
+            if (!empty($cart_totals)) {
                 $response['success']        = true;
                 $response['data']           = $cart_totals;
                 $response['data']['code']   = $discount_code;
@@ -695,10 +695,10 @@ 
             }
             
             // Allow for custom discount code handling
-            $response = apply_filters( 'wpinv_ajax_discount_response', $response );
+            $response = apply_filters('wpinv_ajax_discount_response', $response);
         }
         
-        wp_send_json( $response );
+        wp_send_json($response);
     }
 
     /**
@@ -710,75 +710,75 @@ 
         global $invoicing, $wpi_checkout_id, $cart_total;
 
         // Check nonce.
-        if ( ! isset( $_POST['wpinv_payment_form'] ) || ! wp_verify_nonce( $_POST['wpinv_payment_form'], 'wpinv_payment_form' ) ) {
-            wp_send_json_error( __( 'Security checks failed.', 'invoicing' ) );
+        if (!isset($_POST['wpinv_payment_form']) || !wp_verify_nonce($_POST['wpinv_payment_form'], 'wpinv_payment_form')) {
+            wp_send_json_error(__('Security checks failed.', 'invoicing'));
         }
 
         // Prepare submitted data...
-        $data = wp_unslash( $_POST );
+        $data = wp_unslash($_POST);
 
         // ... form fields...
-        if ( empty( $data['form_id'] ) || 'publish' != get_post_status( $data['form_id'] ) ) {
-            wp_send_json_error( __( 'This payment form is no longer active.', 'invoicing' ) );
+        if (empty($data['form_id']) || 'publish' != get_post_status($data['form_id'])) {
+            wp_send_json_error(__('This payment form is no longer active.', 'invoicing'));
         }
 
-        if ( empty( $data['billing_email'] ) || ! is_email( $data['billing_email'] ) ) {
-            wp_send_json_error( __( 'Provide a valid billing email.', 'invoicing' ) );
+        if (empty($data['billing_email']) || !is_email($data['billing_email'])) {
+            wp_send_json_error(__('Provide a valid billing email.', 'invoicing'));
         }
 
         $prepared = array(
-            'billing_email'                    => sanitize_email( $data['billing_email'] ),
-            __( 'Billing Email', 'invoicing' ) => sanitize_email( $data['billing_email'] ),
-            __( 'Form Id', 'invoicing' )       => absint( $data['form_id'] ),
+            'billing_email'                    => sanitize_email($data['billing_email']),
+            __('Billing Email', 'invoicing') => sanitize_email($data['billing_email']),
+            __('Form Id', 'invoicing')       => absint($data['form_id']),
         );
 
-        $prepared['billing_email'] = sanitize_email( $data['billing_email'] );
+        $prepared['billing_email'] = sanitize_email($data['billing_email']);
 
-        $fields = $invoicing->form_elements->get_form_elements( $data['form_id'] );
+        $fields = $invoicing->form_elements->get_form_elements($data['form_id']);
 
         // ... and form items.
-        $items          = $invoicing->form_elements->get_form_items( $data['form_id'] );
+        $items          = $invoicing->form_elements->get_form_items($data['form_id']);
         $prepared_items = array();
         $address_fields = array();
 
-        if ( ! empty( $data['wpinv-items'] ) ) {
+        if (!empty($data['wpinv-items'])) {
 
-            $selected_items = wpinv_clean( $data['wpinv-items'] );
+            $selected_items = wpinv_clean($data['wpinv-items']);
 
-            foreach ( $items as $item ) {
+            foreach ($items as $item) {
 
-                if ( ! empty( $item['required'] ) && ! isset( $selected_items[ $item['id'] ] ) ) {
-                    wp_send_json_error( __( 'A required item is missing.', 'invoicing' ) );
+                if (!empty($item['required']) && !isset($selected_items[$item['id']])) {
+                    wp_send_json_error(__('A required item is missing.', 'invoicing'));
                 }
 
-                if ( ! isset( $selected_items[ $item['id'] ] ) ) {
+                if (!isset($selected_items[$item['id']])) {
                     continue;
                 }
 
                 $quantity = 1;
 
-                if ( ! empty( $item['allow_quantities'] ) && ! empty( $data["wpinv-item-{$item['id']}-quantity"] ) ) {
+                if (!empty($item['allow_quantities']) && !empty($data["wpinv-item-{$item['id']}-quantity"])) {
 
-                    $quantity = intval( $data["wpinv-item-{$item['id']}-quantity"] );
+                    $quantity = intval($data["wpinv-item-{$item['id']}-quantity"]);
 
-                    if ( empty( $quantity ) ) {
+                    if (empty($quantity)) {
                         $quantity = 1;
                     }
                 }
 
                 // Custom pricing.
-                if ( ! empty( $item['custom_price'] ) ) {
+                if (!empty($item['custom_price'])) {
 
-                    $minimum_price = wpinv_sanitize_amount( $item['minimum_price'] );
-                    $set_price     = wpinv_sanitize_amount( $selected_items[ $item['id'] ] );
+                    $minimum_price = wpinv_sanitize_amount($item['minimum_price']);
+                    $set_price     = wpinv_sanitize_amount($selected_items[$item['id']]);
 
-                    if ( $set_price < $minimum_price ) {
-                        wp_send_json_error( __( 'The provided amount is less than the minimum allowed value.', 'invoicing' ) );
+                    if ($set_price < $minimum_price) {
+                        wp_send_json_error(__('The provided amount is less than the minimum allowed value.', 'invoicing'));
                     }
 
                     $prepared_items[] = array(
                         'id'           =>$item['id'],
-                        'item_price'   => wpinv_sanitize_amount( $item['price'] ),
+                        'item_price'   => wpinv_sanitize_amount($item['price']),
                         'custom_price' => $set_price,
                         'name'         => $item['title'],
                         'quantity'     => $quantity,
@@ -788,8 +788,8 @@ 
 
                     $prepared_items[] = array(
                         'id'           => $item['id'],
-                        'item_price'   => wpinv_sanitize_amount( $item['price'] ),
-                        'custom_price' => wpinv_sanitize_amount( $item['price'] ),
+                        'item_price'   => wpinv_sanitize_amount($item['price']),
+                        'custom_price' => wpinv_sanitize_amount($item['price']),
                         'name'         => $item['title'],
                         'quantity'     => $quantity,
                     );
@@ -800,64 +800,64 @@ 
 
         } else {
 
-            wp_send_json_error( __( 'You have not selected any items.', 'invoicing' ) );
+            wp_send_json_error(__('You have not selected any items.', 'invoicing'));
 
         }
 
         // Are all required fields provided?
-        foreach ( $fields as $field ) {
+        foreach ($fields as $field) {
 
-            if ( ! empty( $field['premade'] ) ) {
+            if (!empty($field['premade'])) {
                 continue;
             }
 
-            if ( ! empty( $field['required'] ) && empty( $data[ $field['id'] ] ) ) {
-                wp_send_json_error( __( 'Some required fields have not been filled.', 'invoicing' ) );
+            if (!empty($field['required']) && empty($data[$field['id']])) {
+                wp_send_json_error(__('Some required fields have not been filled.', 'invoicing'));
             }
 
-            if ( $field['type'] == 'address' ) {
+            if ($field['type'] == 'address') {
 
-                foreach ( $field['fields'] as $address_field ) {
+                foreach ($field['fields'] as $address_field) {
 
-                    if ( empty( $address_field['visible'] ) ) {
+                    if (empty($address_field['visible'])) {
                         continue;
                     }
 
-                    if ( ! empty( $address_field['required'] ) && empty( $data[ $address_field['name'] ] ) ) {
-                        wp_send_json_error( __( 'Some required fields have not been filled.', 'invoicing' ) );
+                    if (!empty($address_field['required']) && empty($data[$address_field['name']])) {
+                        wp_send_json_error(__('Some required fields have not been filled.', 'invoicing'));
                     }
 
-                    if ( isset( $data[ $address_field['name'] ] ) ) {
-                        $label = str_replace( 'wpinv_', '', $address_field['name'] );
-                        $address_fields[ $label ] = wpinv_clean( $data[ $address_field['name'] ] );
+                    if (isset($data[$address_field['name']])) {
+                        $label = str_replace('wpinv_', '', $address_field['name']);
+                        $address_fields[$label] = wpinv_clean($data[$address_field['name']]);
                     }
 
                 }
 
-            } else if ( isset( $data[ $field['id'] ] ) ) {
+            } else if (isset($data[$field['id']])) {
                 $label = $field['id'];
 
-                if ( isset( $field['label'] ) ) {
+                if (isset($field['label'])) {
                     $label = $field['label'];
                 }
 
-                $prepared[ wpinv_clean( $label ) ] = wpinv_clean( $data[ $field['id'] ] );
+                $prepared[wpinv_clean($label)] = wpinv_clean($data[$field['id']]);
             }
 
         }
 
-        $user = get_user_by( 'email', $prepared['billing_email'] );
+        $user = get_user_by('email', $prepared['billing_email']);
 
-        if ( empty( $user ) ) {
-            $user = wpinv_create_user( $prepared['billing_email'] );
+        if (empty($user)) {
+            $user = wpinv_create_user($prepared['billing_email']);
         }
 
-        if ( is_wp_error( $user ) ) {
-            wp_send_json_error( $user->get_error_message() );
+        if (is_wp_error($user)) {
+            wp_send_json_error($user->get_error_message());
         }
 
-        if ( is_numeric( $user ) ) {
-            $user = get_user_by( 'id', $user );
+        if (is_numeric($user)) {
+            $user = get_user_by('id', $user);
         }
 
         // Create the invoice.
@@ -872,34 +872,34 @@ 
             true
         );
 
-        if ( is_wp_error( $created ) ) {
-            wp_send_json_error( $created->get_error_message() );
+        if (is_wp_error($created)) {
+            wp_send_json_error($created->get_error_message());
         }
 
-        if ( empty( $created ) ) {
-            wp_send_json_error( __( 'Could not create your invoice.', 'invoicing' ) );
+        if (empty($created)) {
+            wp_send_json_error(__('Could not create your invoice.', 'invoicing'));
         }
 
-        unset( $prepared['billing_email'] );
-        update_post_meta( $created->ID, 'payment_form_data', $prepared );
+        unset($prepared['billing_email']);
+        update_post_meta($created->ID, 'payment_form_data', $prepared);
 
         $wpi_checkout_id = $created->ID;
         $cart_total = wpinv_price(
             wpinv_format_amount(
-                wpinv_get_cart_total( $created->get_cart_details(), NULL, $created ) ),
+                wpinv_get_cart_total($created->get_cart_details(), NULL, $created) ),
                 $created->get_currency()
         );
 
         $data                   = array();
         $data['invoice_id']     = $created->ID;
-        $data['cart_discounts'] = $created->get_discounts( true );
+        $data['cart_discounts'] = $created->get_discounts(true);
 
-        wpinv_set_checkout_session( $data );
-        add_filter( 'wp_redirect', array( $invoicing->form_elements, 'send_redirect_response' ) );
-        add_action( 'wpinv_pre_send_back_to_checkout', array( $invoicing->form_elements, 'checkout_error' ) );
+        wpinv_set_checkout_session($data);
+        add_filter('wp_redirect', array($invoicing->form_elements, 'send_redirect_response'));
+        add_action('wpinv_pre_send_back_to_checkout', array($invoicing->form_elements, 'checkout_error'));
         
-        if ( ! defined( 'WPINV_CHECKOUT' ) ) {
-            define( 'WPINV_CHECKOUT', true );
+        if (!defined('WPINV_CHECKOUT')) {
+            define('WPINV_CHECKOUT', true);
         }
 
         wpinv_process_checkout();
@@ -917,51 +917,51 @@ 
     public static function get_payment_form_states_field() {
         global $invoicing;
 
-        if ( empty( $_GET['country'] ) || empty( $_GET['form'] ) ) {
+        if (empty($_GET['country']) || empty($_GET['form'])) {
             exit;
         }
 
-        $elements = $invoicing->form_elements->get_form_elements( $_GET['form'] );
+        $elements = $invoicing->form_elements->get_form_elements($_GET['form']);
 
-        if ( empty( $elements ) ) {
+        if (empty($elements)) {
             exit;
         }
 
         $address_fields = array();
-        foreach ( $elements as $element ) {
-            if ( 'address' === $element['type'] ) {
+        foreach ($elements as $element) {
+            if ('address' === $element['type']) {
                 $address_fields = $element;
                 break;
             }
         }
 
-        if ( empty( $address_fields ) ) {
+        if (empty($address_fields)) {
             exit;
         }
 
-        foreach( $address_fields['fields'] as $address_field ) {
+        foreach ($address_fields['fields'] as $address_field) {
 
-            if ( 'wpinv_state' == $address_field['name'] ) {
+            if ('wpinv_state' == $address_field['name']) {
 
                 $label = $address_field['label'];
 
-                if ( ! empty( $address_field['required'] ) ) {
+                if (!empty($address_field['required'])) {
                     $label .= "<span class='text-danger'> *</span>";
                 }
 
-                $states = wpinv_get_country_states( $_GET['country'] );
+                $states = wpinv_get_country_states($_GET['country']);
 
-                if ( ! empty( $states ) ) {
+                if (!empty($states)) {
 
                     $html = aui()->select(
                             array(
                                 'options'          => $states,
-                                'name'             => esc_attr( $address_field['name'] ),
-                                'id'               => esc_attr( $address_field['name'] ),
-                                'placeholder'      => esc_attr( $address_field['placeholder'] ),
+                                'name'             => esc_attr($address_field['name']),
+                                'id'               => esc_attr($address_field['name']),
+                                'placeholder'      => esc_attr($address_field['placeholder']),
                                 'required'         => (bool) $address_field['required'],
                                 'no_wrap'          => true,
-                                'label'            => wp_kses_post( $label ),
+                                'label'            => wp_kses_post($label),
                                 'select2'          => false,
                             )
                         );
@@ -970,10 +970,10 @@ 
 
                     $html = aui()->input(
                             array(
-                                'name'       => esc_attr( $address_field['name'] ),
-                                'id'         => esc_attr( $address_field['name'] ),
+                                'name'       => esc_attr($address_field['name']),
+                                'id'         => esc_attr($address_field['name']),
                                 'required'   => (bool) $address_field['required'],
-                                'label'      => wp_kses_post( $label ),
+                                'label'      => wp_kses_post($label),
                                 'no_wrap'    => true,
                                 'type'       => 'text',
                             )
@@ -981,7 +981,7 @@ 
 
                 }
 
-                wp_send_json_success( str_replace( 'sr-only', '', $html ) );
+                wp_send_json_success(str_replace('sr-only', '', $html));
                 exit;
 
             }
@@ -1000,77 +1000,77 @@ 
         global $invoicing;
 
         // Check nonce.
-        check_ajax_referer( 'wpinv_payment_form', 'wpinv_payment_form' );
+        check_ajax_referer('wpinv_payment_form', 'wpinv_payment_form');
 
         // Prepare submitted data...
-        $data = wp_unslash( $_POST );
+        $data = wp_unslash($_POST);
 
         // ... form fields...
-        if ( empty( $data['form_id'] ) || 'publish' != get_post_status( $data['form_id'] ) ) {
+        if (empty($data['form_id']) || 'publish' != get_post_status($data['form_id'])) {
             exit;
         }
 
         // ... and form items.
-        $items     = $invoicing->form_elements->get_form_items( $data['form_id'] );
+        $items     = $invoicing->form_elements->get_form_items($data['form_id']);
         $total     = 0;
         $tax       = 0;
         $sub_total = 0;
         $country   = wpinv_default_billing_country();
         $state     = false;
 
-        if ( ! empty( $_POST['wpinv_country'] ) ) {
+        if (!empty($_POST['wpinv_country'])) {
             $country = $_POST['wpinv_country'];
         }
 
-        if ( ! empty( $_POST['wpinv_state'] ) ) {
+        if (!empty($_POST['wpinv_state'])) {
             $state = $_POST['wpinv_state'];
         }
 
-        if ( ! empty( $data['wpinv-items'] ) ) {
+        if (!empty($data['wpinv-items'])) {
 
-            $selected_items = wpinv_clean( $data['wpinv-items'] );
+            $selected_items = wpinv_clean($data['wpinv-items']);
 
-            foreach ( $items as $item ) {
+            foreach ($items as $item) {
 
-                if ( ! isset( $selected_items[ $item['id'] ] ) ) {
+                if (!isset($selected_items[$item['id']])) {
                     continue;
                 }
 
                 $quantity = 1;
 
-                if ( ! empty( $item['allow_quantities'] ) && ! empty( $data["wpinv-item-{$item['id']}-quantity"] ) ) {
+                if (!empty($item['allow_quantities']) && !empty($data["wpinv-item-{$item['id']}-quantity"])) {
 
-                    $quantity = intval( $data["wpinv-item-{$item['id']}-quantity"] );
+                    $quantity = intval($data["wpinv-item-{$item['id']}-quantity"]);
 
-                    if ( 1 > $quantity ) {
+                    if (1 > $quantity) {
                         $quantity = 1;
                     }
 
                 }
 
                 // Custom pricing.
-                $price = wpinv_sanitize_amount( $item['price'] );
-                if ( ! empty( $item['custom_price'] ) ) {
+                $price = wpinv_sanitize_amount($item['price']);
+                if (!empty($item['custom_price'])) {
 
-                    $minimum_price = wpinv_sanitize_amount( $item['minimum_price'] );
-                    $set_price     = wpinv_sanitize_amount( $selected_items[ $item['id'] ] );
+                    $minimum_price = wpinv_sanitize_amount($item['minimum_price']);
+                    $set_price     = wpinv_sanitize_amount($selected_items[$item['id']]);
 
-                    if ( $set_price < $minimum_price ) {
+                    if ($set_price < $minimum_price) {
                         $set_price = $minimum_price;
                     }
 
-                    $price = wpinv_sanitize_amount( $set_price );
+                    $price = wpinv_sanitize_amount($set_price);
 
                 }
 
-                $price  = $quantity * floatval( $price );
+                $price = $quantity * floatval($price);
 
-                if ( wpinv_use_taxes() ) {
+                if (wpinv_use_taxes()) {
 
-                    $rate = wpinv_get_tax_rate( $country, $state, (int) $item['id'] );
+                    $rate = wpinv_get_tax_rate($country, $state, (int) $item['id']);
 
-                    if ( wpinv_prices_include_tax() ) {
-                        $pre_tax  = ( $price - $price * $rate * 0.01 );
+                    if (wpinv_prices_include_tax()) {
+                        $pre_tax  = ($price - $price * $rate * 0.01);
                         $item_tax = $price - $pre_tax;
                     } else {
                         $pre_tax  = $price;
@@ -1082,17 +1082,17 @@ 
                     $total     = $sub_total + $tax;
 
                 } else {
-                    $total  = $total + $price;
+                    $total = $total + $price;
                 }
 
             }
 
         }
 
-        wp_send_json_success( array(
-            'total'     => wpinv_price( wpinv_format_amount( $total ) ),
-            'tax'       => wpinv_price( wpinv_format_amount( $tax ) ),
-            'sub_total' => wpinv_price( wpinv_format_amount( $sub_total ) ),
+        wp_send_json_success(array(
+            'total'     => wpinv_price(wpinv_format_amount($total)),
+            'tax'       => wpinv_price(wpinv_format_amount($tax)),
+            'sub_total' => wpinv_price(wpinv_format_amount($sub_total)),
         ));
         exit;
     }
@@ -1105,53 +1105,53 @@ 
     public static function buy_items() {
         $user_id = get_current_user_id();
 
-        if ( empty( $user_id ) ) { // If not logged in then lets redirect to the login page
-            wp_send_json( array(
-                'success' => wp_login_url( wp_get_referer() )
-            ) );
+        if (empty($user_id)) { // If not logged in then lets redirect to the login page
+            wp_send_json(array(
+                'success' => wp_login_url(wp_get_referer())
+            ));
         } else {
             // Only check nonce if logged in as it could be cached when logged out.
-            if ( ! isset( $_POST['wpinv_buy_nonce'] ) || ! wp_verify_nonce( $_POST['wpinv_buy_nonce'], 'wpinv_buy_items' ) ) {
-                wp_send_json( array(
-                    'error' => __( 'Security checks failed.', 'invoicing' )
-                ) );
+            if (!isset($_POST['wpinv_buy_nonce']) || !wp_verify_nonce($_POST['wpinv_buy_nonce'], 'wpinv_buy_items')) {
+                wp_send_json(array(
+                    'error' => __('Security checks failed.', 'invoicing')
+                ));
                 wp_die();
             }
 
             // allow to set a custom price through post_id
             $items = $_POST['items'];
-            $related_post_id = isset( $_POST['post_id'] ) ? (int)$_POST['post_id'] : 0;
-            $custom_item_price = $related_post_id ? abs( get_post_meta( $related_post_id, '_wpi_custom_price', true ) ) : 0;
+            $related_post_id = isset($_POST['post_id']) ? (int) $_POST['post_id'] : 0;
+            $custom_item_price = $related_post_id ? abs(get_post_meta($related_post_id, '_wpi_custom_price', true)) : 0;
 
             $cart_items = array();
-            if ( $items ) {
-                $items = explode( ',', $items );
+            if ($items) {
+                $items = explode(',', $items);
 
-                foreach( $items as $item ) {
+                foreach ($items as $item) {
                     $item_id = $item;
                     $quantity = 1;
 
-                    if ( strpos( $item, '|' ) !== false ) {
-                        $item_parts = explode( '|', $item );
+                    if (strpos($item, '|') !== false) {
+                        $item_parts = explode('|', $item);
                         $item_id = $item_parts[0];
                         $quantity = $item_parts[1];
                     }
 
-                    if ( $item_id && $quantity ) {
+                    if ($item_id && $quantity) {
                         $cart_items_arr = array(
-                            'id'            => (int)$item_id,
-                            'quantity'      => (int)$quantity
+                            'id'            => (int) $item_id,
+                            'quantity'      => (int) $quantity
                         );
 
                         // If there is a related post id then add it to meta
-                        if ( $related_post_id ) {
+                        if ($related_post_id) {
                             $cart_items_arr['meta'] = array(
                                 'post_id'   => $related_post_id
                             );
                         }
 
                         // If there is a custom price then set it.
-                        if ( $custom_item_price ) {
+                        if ($custom_item_price) {
                             $cart_items_arr['custom_price'] = $custom_item_price;
                         }
 
@@ -1167,37 +1167,37 @@ 
              * @param int $related_post_id The related post id if any.
              * @since 1.0.0
              */
-            $cart_items = apply_filters( 'wpinv_buy_cart_items', $cart_items, $related_post_id );
+            $cart_items = apply_filters('wpinv_buy_cart_items', $cart_items, $related_post_id);
 
             // Make sure its not in the cart already, if it is then redirect to checkout.
             $cart_invoice = wpinv_get_invoice_cart();
 
-            if ( isset( $cart_invoice->items ) && !empty( $cart_invoice->items ) && !empty( $cart_items ) && serialize( $cart_invoice->items ) == serialize( $cart_items ) ) {
-                wp_send_json( array(
+            if (isset($cart_invoice->items) && !empty($cart_invoice->items) && !empty($cart_items) && serialize($cart_invoice->items) == serialize($cart_items)) {
+                wp_send_json(array(
                     'success' =>  $cart_invoice->get_checkout_payment_url()
-                ) );
+                ));
                 wp_die();
             }
 
             // Check if user has invoice with same items waiting to be paid.
-            $user_invoices = wpinv_get_users_invoices( $user_id , 10 , false , 'wpi-pending' );
-            if ( !empty( $user_invoices ) ) {
-                foreach( $user_invoices as $user_invoice ) {
+            $user_invoices = wpinv_get_users_invoices($user_id, 10, false, 'wpi-pending');
+            if (!empty($user_invoices)) {
+                foreach ($user_invoices as $user_invoice) {
                     $user_cart_details = array();
-                    $invoice  = wpinv_get_invoice( $user_invoice->ID );
+                    $invoice = wpinv_get_invoice($user_invoice->ID);
                     $cart_details = $invoice->get_cart_details();
 
-                    if ( !empty( $cart_details ) ) {
-                        foreach ( $cart_details as $invoice_item ) {
+                    if (!empty($cart_details)) {
+                        foreach ($cart_details as $invoice_item) {
                             $ii_arr = array();
-                            $ii_arr['id'] = (int)$invoice_item['id'];
-                            $ii_arr['quantity'] = (int)$invoice_item['quantity'];
+                            $ii_arr['id'] = (int) $invoice_item['id'];
+                            $ii_arr['quantity'] = (int) $invoice_item['quantity'];
 
-                            if (isset( $invoice_item['meta'] ) && !empty( $invoice_item['meta'] ) ) {
+                            if (isset($invoice_item['meta']) && !empty($invoice_item['meta'])) {
                                 $ii_arr['meta'] = $invoice_item['meta'];
                             }
 
-                            if ( isset( $invoice_item['custom_price'] ) && !empty( $invoice_item['custom_price'] ) ) {
+                            if (isset($invoice_item['custom_price']) && !empty($invoice_item['custom_price'])) {
                                 $ii_arr['custom_price'] = $invoice_item['custom_price'];
                             }
 
@@ -1205,17 +1205,17 @@ 
                         }
                     }
 
-                    if ( !empty( $user_cart_details ) && serialize( $cart_items ) == serialize( $user_cart_details ) ) {
-                        wp_send_json( array(
+                    if (!empty($user_cart_details) && serialize($cart_items) == serialize($user_cart_details)) {
+                        wp_send_json(array(
                             'success' =>  $invoice->get_checkout_payment_url()
-                        ) );
+                        ));
                         wp_die();
                     }
                 }
             }
 
             // Create invoice and send user to checkout
-            if ( !empty( $cart_items ) ) {
+            if (!empty($cart_items)) {
                 $invoice_data = array(
                     'status'        =>  'wpi-pending',
                     'created_via'   =>  'wpi',
@@ -1223,21 +1223,21 @@ 
                     'cart_details'  =>  $cart_items,
                 );
 
-                $invoice = wpinv_insert_invoice( $invoice_data, true );
+                $invoice = wpinv_insert_invoice($invoice_data, true);
 
-                if ( !empty( $invoice ) && isset( $invoice->ID ) ) {
-                    wp_send_json( array(
+                if (!empty($invoice) && isset($invoice->ID)) {
+                    wp_send_json(array(
                         'success' =>  $invoice->get_checkout_payment_url()
-                    ) );
+                    ));
                 } else {
-                    wp_send_json( array(
-                        'error' => __( 'Invoice failed to create', 'invoicing' )
-                    ) );
+                    wp_send_json(array(
+                        'error' => __('Invoice failed to create', 'invoicing')
+                    ));
                 }
             } else {
-                wp_send_json( array(
-                    'error' => __( 'Items not valid.', 'invoicing' )
-                ) );
+                wp_send_json(array(
+                    'error' => __('Items not valid.', 'invoicing')
+                ));
             }
         }
 

includes/class-wpinv-payment-form-elements.php

Spacing +581 added lines, -581 removed lines

@@ -1,6 +1,6 @@ 
 <?php
 
-if ( ! defined( 'ABSPATH' ) ) {
+if (!defined('ABSPATH')) {
     exit; // Exit if accessed directly
 }
 
@@ -13,19 +13,19 @@ 
 
     public function __construct() {
 
-        foreach( $this->get_elements() as $element ) {
+        foreach ($this->get_elements() as $element) {
             $element = $element['type'];
 
-            if ( method_exists( $this, "render_{$element}_template" ) ) {
-                add_action( 'wpinv_payment_form_render_element_template', array( $this, "render_{$element}_template" ), 10, 2 );
+            if (method_exists($this, "render_{$element}_template")) {
+                add_action('wpinv_payment_form_render_element_template', array($this, "render_{$element}_template"), 10, 2);
             }
 
-            if ( method_exists( $this, "edit_{$element}_template" ) ) {
-                add_action( 'wpinv_payment_form_edit_element_template', array( $this, "edit_{$element}_template" ), 10, 2 );
+            if (method_exists($this, "edit_{$element}_template")) {
+                add_action('wpinv_payment_form_edit_element_template', array($this, "edit_{$element}_template"), 10, 2);
             }
 
-            if ( method_exists( $this, "frontend_render_{$element}_template" ) ) {
-                add_action( "wpinv_frontend_render_payment_form_$element", array( $this, "frontend_render_{$element}_template" ), 10, 3 );
+            if (method_exists($this, "frontend_render_{$element}_template")) {
+                add_action("wpinv_frontend_render_payment_form_$element", array($this, "frontend_render_{$element}_template"), 10, 3);
             }
 
         }
@@ -37,7 +37,7 @@ 
      */
     public function get_elements() {
 
-        if ( ! empty( $this->elements ) ) {
+        if (!empty($this->elements)) {
             return $this->elements;
         }
 
@@ -45,28 +45,28 @@ 
 
             array(
                 'type'     => 'heading',
-                'name'     => __( 'Heading', 'invoicing' ),
+                'name'     => __('Heading', 'invoicing'),
                 'defaults' => array(
                     'level' => 'h2',
-                    'text'  => __( 'Heading', 'invoicing' ),
+                    'text'  => __('Heading', 'invoicing'),
                 )
             ),
 
             array(
                 'type' => 'paragraph',
-                'name' => __( 'Paragraph', 'invoicing' ),
+                'name' => __('Paragraph', 'invoicing'),
                 'defaults'  => array(
-                    'text'  => __( 'Paragraph text', 'invoicing' ),
+                    'text'  => __('Paragraph text', 'invoicing'),
                 )
             ),
 
             array( 
                 'type' => 'alert',
-                'name' => __( 'Alert', 'invoicing' ),
+                'name' => __('Alert', 'invoicing'),
                 'defaults'  => array(
                     'value'        => '',
                     'class'        => 'alert-warning',
-                    'text'         => __( 'Alert', 'invoicing' ),
+                    'text'         => __('Alert', 'invoicing'),
                     'dismissible'  => false,
                 )
             ),
@@ -82,11 +82,11 @@ 
 
             array(
                 'type' => 'text',
-                'name' => __( 'Text Input', 'invoicing' ),
+                'name' => __('Text Input', 'invoicing'),
                 'defaults'  => array(
-                    'placeholder'  => __( 'Enter some text', 'invoicing' ),
+                    'placeholder'  => __('Enter some text', 'invoicing'),
                     'value'        => '',
-                    'label'        => __( 'Field Label', 'invoicing' ),
+                    'label'        => __('Field Label', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -94,11 +94,11 @@ 
 
             array(
                 'type' => 'textarea',
-                'name' => __( 'Textarea', 'invoicing' ),
+                'name' => __('Textarea', 'invoicing'),
                 'defaults'         => array(
-                    'placeholder'  => __( 'Enter your text hear', 'invoicing' ),
+                    'placeholder'  => __('Enter your text hear', 'invoicing'),
                     'value'        => '',
-                    'label'        => __( 'Textarea Label', 'invoicing' ),
+                    'label'        => __('Textarea Label', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -106,27 +106,27 @@ 
 
             array(
                 'type' => 'select',
-                'name' => __( 'Dropdown', 'invoicing' ),
+                'name' => __('Dropdown', 'invoicing'),
                 'defaults'         => array(
-                    'placeholder'  => __( 'Select a value', 'invoicing' ),
+                    'placeholder'  => __('Select a value', 'invoicing'),
                     'value'        => '',
-                    'label'        => __( 'Dropdown Label', 'invoicing' ),
+                    'label'        => __('Dropdown Label', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                     'options'      => array(
-                        esc_attr__( 'Option One', 'invoicing' ),
-                        esc_attr__( 'Option Two', 'invoicing' ),
-                        esc_attr__( 'Option Three', 'invoicing' )
+                        esc_attr__('Option One', 'invoicing'),
+                        esc_attr__('Option Two', 'invoicing'),
+                        esc_attr__('Option Three', 'invoicing')
                     ),
                 )
             ),
 
             array(
                 'type' => 'checkbox',
-                'name' => __( 'Checkbox', 'invoicing' ),
+                'name' => __('Checkbox', 'invoicing'),
                 'defaults'         => array(
                     'value'        => '',
-                    'label'        => __( 'Checkbox Label', 'invoicing' ),
+                    'label'        => __('Checkbox Label', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -134,24 +134,24 @@ 
 
             array( 
                 'type' => 'radio',
-                'name' => __( 'Multiple Choice', 'invoicing' ),
+                'name' => __('Multiple Choice', 'invoicing'),
                 'defaults'     => array(
-                    'label'    => __( 'Select one choice', 'invoicing' ),
+                    'label'    => __('Select one choice', 'invoicing'),
                     'options'  => array(
-                        esc_attr__( 'Choice One', 'invoicing' ),
-                        esc_attr__( 'Choice Two', 'invoicing' ),
-                        esc_attr__( 'Choice Three', 'invoicing' )
+                        esc_attr__('Choice One', 'invoicing'),
+                        esc_attr__('Choice Two', 'invoicing'),
+                        esc_attr__('Choice Three', 'invoicing')
                     ),
                 )
             ),
 
             array( 
                 'type' => 'date',
-                'name' => __( 'Date', 'invoicing' ),
+                'name' => __('Date', 'invoicing'),
                 'defaults' => array(
                     'placeholder'  => '',
                     'value'        => '',
-                    'label'        => __( 'Date', 'invoicing' ),
+                    'label'        => __('Date', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -159,11 +159,11 @@ 
 
             array( 
                 'type' => 'time',
-                'name' => __( 'Time', 'invoicing' ),
+                'name' => __('Time', 'invoicing'),
                 'defaults' => array(
                     'placeholder'  => '',
                     'value'        => '',
-                    'label'        => __( 'Time', 'invoicing' ),
+                    'label'        => __('Time', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -171,11 +171,11 @@ 
 
             array( 
                 'type' => 'number',
-                'name' => __( 'Number', 'invoicing' ),
+                'name' => __('Number', 'invoicing'),
                 'defaults' => array(
                     'placeholder'  => '',
                     'value'        => '',
-                    'label'        => __( 'Number', 'invoicing' ),
+                    'label'        => __('Number', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -183,11 +183,11 @@ 
 
             array( 
                 'type' => 'website',
-                'name' => __( 'Website', 'invoicing' ),
+                'name' => __('Website', 'invoicing'),
                 'defaults' => array(
                     'placeholder'  => 'http://example.com',
                     'value'        => '',
-                    'label'        => __( 'Website', 'invoicing' ),
+                    'label'        => __('Website', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -195,11 +195,11 @@ 
 
             array( 
                 'type' => 'email',
-                'name' => __( 'Email', 'invoicing' ),
+                'name' => __('Email', 'invoicing'),
                 'defaults'  => array(
                     'placeholder'  => 'jon@snow.com',
                     'value'        => '',
-                    'label'        => __( 'Email Address', 'invoicing' ),
+                    'label'        => __('Email Address', 'invoicing'),
                     'description'  => '',
                     'required'     => false,
                 )
@@ -207,14 +207,14 @@ 
 
             array( 
                 'type' => 'address',
-                'name' => __( 'Address', 'invoicing' ),
+                'name' => __('Address', 'invoicing'),
                 'defaults'  => array(
 
                     'fields' => array(
                         array(
                             'placeholder'  => 'Jon',
                             'value'        => '',
-                            'label'        => __( 'First Name', 'invoicing' ),
+                            'label'        => __('First Name', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -224,7 +224,7 @@ 
                         array(
                             'placeholder'  => 'Snow',
                             'value'        => '',
-                            'label'        => __( 'Last Name', 'invoicing' ),
+                            'label'        => __('Last Name', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -234,7 +234,7 @@ 
                         array(
                             'placeholder'  => '',
                             'value'        => '',
-                            'label'        => __( 'Address', 'invoicing' ),
+                            'label'        => __('Address', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -244,7 +244,7 @@ 
                         array(
                             'placeholder'  => '',
                             'value'        => '',
-                            'label'        => __( 'City', 'invoicing' ),
+                            'label'        => __('City', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -252,9 +252,9 @@ 
                         ),
 
                         array(
-                            'placeholder'  => __( 'Select your country' ),
+                            'placeholder'  => __('Select your country'),
                             'value'        => '',
-                            'label'        => __( 'Country', 'invoicing' ),
+                            'label'        => __('Country', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -262,9 +262,9 @@ 
                         ),
 
                         array(
-                            'placeholder'  => __( 'Choose a state', 'invoicing' ),
+                            'placeholder'  => __('Choose a state', 'invoicing'),
                             'value'        => '',
-                            'label'        => __( 'State / Province', 'invoicing' ),
+                            'label'        => __('State / Province', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -274,7 +274,7 @@ 
                         array(
                             'placeholder'  => '',
                             'value'        => '',
-                            'label'        => __( 'ZIP / Postcode', 'invoicing' ),
+                            'label'        => __('ZIP / Postcode', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -284,7 +284,7 @@ 
                         array(
                             'placeholder'  => '',
                             'value'        => '',
-                            'label'        => __( 'Phone', 'invoicing' ),
+                            'label'        => __('Phone', 'invoicing'),
                             'description'  => '',
                             'required'     => false,
                             'visible'      => true,
@@ -296,11 +296,11 @@ 
 
             array( 
                 'type' => 'billing_email',
-                'name' => __( 'Billing Email', 'invoicing' ),
+                'name' => __('Billing Email', 'invoicing'),
                 'defaults'  => array(
                     'placeholder'  => 'jon@snow.com',
                     'value'        => '',
-                    'label'        => __( 'Billing Email', 'invoicing' ),
+                    'label'        => __('Billing Email', 'invoicing'),
                     'description'  => '',
                     'premade'      => true,
                 )
@@ -319,7 +319,7 @@ 
 
             array( 
                 'type' => 'items',
-                'name' => __( 'Items', 'invoicing' ),
+                'name' => __('Items', 'invoicing'),
                 'defaults'  => array(
                     'value'        => '',
                     'items_type'   => 'total',
@@ -330,25 +330,25 @@ 
 
             array( 
                 'type'       => 'pay_button',
-                'name'       => __( 'Payment Button', 'invoicing' ),
+                'name'       => __('Payment Button', 'invoicing'),
                 'defaults'   => array(
                     'value'        => '',
                     'class'        => 'btn-primary',
-                    'label'        => __( 'Pay Now »', 'invoicing' ),
-                    'description'  => __( 'By continuing with our payment, you are agreeing to our privacy policy and terms of service.', 'invoicing' ),
+                    'label'        => __('Pay Now »', 'invoicing'),
+                    'description'  => __('By continuing with our payment, you are agreeing to our privacy policy and terms of service.', 'invoicing'),
                     'premade'      => true,
                 )
             )
         );
 
-        $this->elements = apply_filters( 'wpinv_filter_core_payment_form_elements', $this->elements );
+        $this->elements = apply_filters('wpinv_filter_core_payment_form_elements', $this->elements);
         return $this->elements;
     }
 
     /**
      * Returns the restrict markup.
      */
-    public function get_restrict_markup( $field, $field_type ) {
+    public function get_restrict_markup($field, $field_type) {
         $restrict = "$field.type=='$field_type'";
         return "v-if=\"$restrict\"";
     }
@@ -356,15 +356,15 @@ 
     /**
      * Renders the title element template.
      */
-    public function render_heading_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'heading' );
+    public function render_heading_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'heading');
         echo "<component :is='$field.level' $restrict v-html='$field.text'></component>";
     }
 
     /**
      * Renders the title element on the frontend.
      */
-    public function frontend_render_heading_template( $field ) {
+    public function frontend_render_heading_template($field) {
         $tag = $field['level'];
         echo "<$tag>{$field['text']}</$tag>";
     }
@@ -372,10 +372,10 @@ 
     /**
      * Renders the edit title element template.
      */
-    public function edit_heading_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'heading' );
-        $label    = __( 'Heading', 'invoicing' );
-        $label2   = __( 'Select Heading Level', 'invoicing' );
+    public function edit_heading_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'heading');
+        $label    = __('Heading', 'invoicing');
+        $label2   = __('Select Heading Level', 'invoicing');
         $id       = $field . '.id + "_edit"';
         $id2      = $field . '.id + "_edit2"';
 
@@ -407,8 +407,8 @@ 
     /**
      * Renders a paragraph element template.
      */
-    public function render_paragraph_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'paragraph' );
+    public function render_paragraph_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'paragraph');
         $label    = "$field.text";
         echo "<p $restrict v-html='$label' style='font-size: 16px;'></p>";
     }
@@ -416,16 +416,16 @@ 
     /**
      * Renders the paragraph element on the frontend.
      */
-    public function frontend_render_paragraph_template( $field ) {
+    public function frontend_render_paragraph_template($field) {
         echo "<p>{$field['text']}</p>";
     }
 
     /**
      * Renders the edit paragraph element template.
      */
-    public function edit_paragraph_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'paragraph' );
-        $label    = __( 'Enter your text', 'invoicing' );
+    public function edit_paragraph_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'paragraph');
+        $label    = __('Enter your text', 'invoicing');
         $id       = $field . '.id + "_edit"';
         echo "
             <div $restrict>
@@ -441,8 +441,8 @@ 
     /**
      * Renders the text element template.
      */
-    public function render_text_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'text' );
+    public function render_text_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'text');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -457,23 +457,23 @@ 
     /**
      * Renders the text element on the frontend.
      */
-    public function frontend_render_text_template( $field ) {
+    public function frontend_render_text_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
-                'placeholder'=> esc_attr( $field['placeholder'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
+                'placeholder'=> esc_attr($field['placeholder']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -484,16 +484,16 @@ 
     /**
      * Renders the edit text element template.
      */
-    public function edit_text_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'text' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_text_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'text');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -521,8 +521,8 @@ 
     /**
      * Renders the textarea element template.
      */
-    public function render_textarea_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'textarea' );
+    public function render_textarea_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'textarea');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -537,24 +537,24 @@ 
     /**
      * Renders the textarea element on the frontend.
      */
-    public function frontend_render_textarea_template( $field ) {
+    public function frontend_render_textarea_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->textarea(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
-                'placeholder'=> esc_attr( $field['placeholder'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
+                'placeholder'=> esc_attr($field['placeholder']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
                 'rows'       => 3,
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -565,16 +565,16 @@ 
     /**
      * Renders the edit textarea element template.
      */
-    public function edit_textarea_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'textarea' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_textarea_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'textarea');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -602,8 +602,8 @@ 
     /**
      * Renders the select element template.
      */
-    public function render_select_template( $field ) {
-        $restrict    = $this->get_restrict_markup( $field, 'select' );
+    public function render_select_template($field) {
+        $restrict    = $this->get_restrict_markup($field, 'select');
         $label       = "$field.label";
         $placeholder = "$field.placeholder";
         $id          = $field . '.id';
@@ -623,24 +623,24 @@ 
     /**
      * Renders the select element on the frontend.
      */
-    public function frontend_render_select_template( $field ) {
+    public function frontend_render_select_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->select(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
-                'placeholder'=> esc_attr( $field['placeholder'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
+                'placeholder'=> esc_attr($field['placeholder']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'options'    => array_combine( $field['options'], $field['options'] ),
+                'options'    => array_combine($field['options'], $field['options']),
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -651,18 +651,18 @@ 
     /**
      * Renders the edit select element template.
      */
-    public function edit_select_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'select' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_select_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'select');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
-        $label6   = __( 'Available Options', 'invoicing' );
+        $label6   = __('Available Options', 'invoicing');
         echo "
             <div $restrict>
                 <div class='form-group'>
@@ -700,8 +700,8 @@ 
     /**
      * Renders the checkbox element template.
      */
-    public function render_checkbox_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'checkbox' );
+    public function render_checkbox_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'checkbox');
         $label    = "$field.label";
         echo "
             <div class='form-check' $restrict>
@@ -716,24 +716,24 @@ 
     /**
      * Renders the checkbox element on the frontend.
      */
-    public function frontend_render_checkbox_template( $field ) {
+    public function frontend_render_checkbox_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'value'      => esc_attr__( 'Yes', 'invoicing' ),
+                'value'      => esc_attr__('Yes', 'invoicing'),
                 'type'       => 'checkbox',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -744,14 +744,14 @@ 
     /**
      * Renders the edit checkbox element template.
      */
-    public function edit_checkbox_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'checkbox' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_checkbox_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'checkbox');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Help text', 'invoicing' );
-        $label3   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label2   = __('Help text', 'invoicing');
+        $label3   = esc_attr__('Add some help text for this field', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label4   = __( 'Is this field required?', 'invoicing' );
+        $label4   = __('Is this field required?', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
         echo "
             <div $restrict>
@@ -775,8 +775,8 @@ 
     /**
      * Renders the radio element template.
      */
-    public function render_radio_template( $field ) {
-        $restrict    = $this->get_restrict_markup( $field, 'radio' );
+    public function render_radio_template($field) {
+        $restrict    = $this->get_restrict_markup($field, 'radio');
         $label       = "$field.label";
         $id          = $field . '.id';
         echo "
@@ -795,20 +795,20 @@ 
     /**
      * Renders the radio element on the frontend.
      */
-    public function frontend_render_radio_template( $field ) {
+    public function frontend_render_radio_template($field) {
         
         echo "<div class='form-group'>";
 
-        if ( ! empty( $field['label'] ) ) {
-            $label = wp_kses_post( $field['label'] );
+        if (!empty($field['label'])) {
+            $label = wp_kses_post($field['label']);
             echo "<legend class='col-form-label'>$label</legend>";
         }
 
-        foreach( $field['options'] as $index => $option ) {
+        foreach ($field['options'] as $index => $option) {
             $id    = $field['id'] . $index;
             $name  = $field['id'];
-            $value = esc_attr( $option );
-            $label = wp_kses_post( $option );
+            $value = esc_attr($option);
+            $label = wp_kses_post($option);
 
             echo "
                 <div class='form-check'>
@@ -818,8 +818,8 @@ 
             ";
         }
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -830,16 +830,16 @@ 
     /**
      * Renders the edit radio element template.
      */
-    public function edit_radio_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'radio' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_radio_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'radio');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Help text', 'invoicing' );
-        $label3   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label2   = __('Help text', 'invoicing');
+        $label3   = esc_attr__('Add some help text for this field', 'invoicing');
         $id2      = $field . '.id + "_edit3"';
-        $label4   = __( 'Is this field required?', 'invoicing' );
+        $label4   = __('Is this field required?', 'invoicing');
         $id3      = $field . '.id + "_edit4"';
-        $label5   = __( 'Available Options', 'invoicing' );
+        $label5   = __('Available Options', 'invoicing');
         echo "
             <div $restrict>
                 <div class='form-group'>
@@ -873,8 +873,8 @@ 
     /**
      * Renders the address element template.
      */
-    public function render_address_template( $field ) {
-        $restrict    = $this->get_restrict_markup( $field, 'address' );
+    public function render_address_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'address');
 
         echo "
             <div class='wpinv-address-wrapper' $restrict>
@@ -896,55 +896,55 @@ 
     /**
      * Renders the address element on the frontend.
      */
-    public function frontend_render_address_template( $field ) {
+    public function frontend_render_address_template($field) {
         
         echo "<div class='wpinv-address-fields'>";
 
-        foreach( $field['fields'] as $address_field ) {
+        foreach ($field['fields'] as $address_field) {
 
-            if ( empty( $address_field['visible'] ) ) {
+            if (empty($address_field['visible'])) {
                 continue;
             }
 
-            $class = esc_attr( $address_field['name'] );
+            $class = esc_attr($address_field['name']);
             echo "<div class='form-group $class'>";
 
             $label = $address_field['label'];
 
-            if ( ! empty( $address_field['required'] ) ) {
+            if (!empty($address_field['required'])) {
                 $label .= "<span class='text-danger'> *</span>";
             }
 
-            if ( 'wpinv_country' == $address_field['name'] ) {
+            if ('wpinv_country' == $address_field['name']) {
 
-                echo aui()->select( array(
+                echo aui()->select(array(
                     'options'          => wpinv_get_country_list(),
-                    'name'             => esc_attr( $address_field['name'] ),
-                    'id'               => esc_attr( $address_field['name'] ),
+                    'name'             => esc_attr($address_field['name']),
+                    'id'               => esc_attr($address_field['name']),
                     'value'            => wpinv_get_default_country(),
-                    'placeholder'      => esc_attr( $address_field['placeholder'] ),
+                    'placeholder'      => esc_attr($address_field['placeholder']),
                     'required'         => (bool) $address_field['required'],
                     'no_wrap'          => true,
-                    'label'            => wp_kses_post( $label ),
+                    'label'            => wp_kses_post($label),
                     'select2'          => false,
                 ));
     
-            } else if ( 'wpinv_state' == $address_field['name'] ) {
+            } else if ('wpinv_state' == $address_field['name']) {
 
-                $states = wpinv_get_country_states( wpinv_get_default_country() );
+                $states = wpinv_get_country_states(wpinv_get_default_country());
                 $state  = wpinv_get_default_state();
 
-                if ( ! empty( $states ) ) {
+                if (!empty($states)) {
 
-                    echo aui()->select( array(
+                    echo aui()->select(array(
                         'options'          => $states,
-                        'name'             => esc_attr( $address_field['name'] ),
-                        'id'               => esc_attr( $address_field['name'] ),
+                        'name'             => esc_attr($address_field['name']),
+                        'id'               => esc_attr($address_field['name']),
                         'value'            => $state,
-                        'placeholder'      => esc_attr( $address_field['placeholder'] ),
+                        'placeholder'      => esc_attr($address_field['placeholder']),
                         'required'         => (bool) $address_field['required'],
                         'no_wrap'          => true,
-                        'label'            => wp_kses_post( $label ),
+                        'label'            => wp_kses_post($label),
                         'select2'          => false,
                     ));
 
@@ -952,10 +952,10 @@ 
 
                     echo aui()->input(
                         array(
-                            'name'       => esc_attr( $address_field['name'] ),
-                            'id'         => esc_attr( $address_field['name'] ),
+                            'name'       => esc_attr($address_field['name']),
+                            'id'         => esc_attr($address_field['name']),
                             'required'   => (bool) $address_field['required'],
-                            'label'      => wp_kses_post( $label ),
+                            'label'      => wp_kses_post($label),
                             'no_wrap'    => true,
                             'type'       => 'text',
                         )
@@ -967,12 +967,12 @@ 
 
                 echo aui()->input(
                     array(
-                        'name'       => esc_attr( $address_field['name'] ),
-                        'id'         => esc_attr( $address_field['name'] ),
+                        'name'       => esc_attr($address_field['name']),
+                        'id'         => esc_attr($address_field['name']),
                         'required'   => (bool) $address_field['required'],
-                        'label'      => wp_kses_post( $label ),
+                        'label'      => wp_kses_post($label),
                         'no_wrap'    => true,
-                        'placeholder' => esc_attr( $address_field['placeholder'] ),
+                        'placeholder' => esc_attr($address_field['placeholder']),
                         'type'       => 'text',
                     )
                 );
@@ -980,8 +980,8 @@ 
             }
             
 
-            if ( ! empty( $address_field['description'] ) ) {
-                $description = wp_kses_post( $address_field['description'] );
+            if (!empty($address_field['description'])) {
+                $description = wp_kses_post($address_field['description']);
                 echo "<small class='form-text text-muted'>$description</small>";
             }
     
@@ -996,13 +996,13 @@ 
     /**
      * Renders the edit address element template.
      */
-    public function edit_address_template( $field ) {
-        $restrict  = $this->get_restrict_markup( $field, 'address' );
-        $label     = __( 'Field Label', 'invoicing' );
-        $label2    = __( 'Placeholder', 'invoicing' );
-        $label3    = __( 'Description', 'invoicing' );
-        $label4    = __( 'Is required', 'invoicing' );
-        $label5    = __( 'Is visible', 'invoicing' );
+    public function edit_address_template($field) {
+        $restrict  = $this->get_restrict_markup($field, 'address');
+        $label     = __('Field Label', 'invoicing');
+        $label2    = __('Placeholder', 'invoicing');
+        $label3    = __('Description', 'invoicing');
+        $label4    = __('Is required', 'invoicing');
+        $label5    = __('Is visible', 'invoicing');
         $id        = $field . '.id + "_edit_label"';
         $id2       = $field . '.id + "_edit_placeholder"';
         $id3       = $field . '.id + "_edit_description"';
@@ -1070,8 +1070,8 @@ 
     /**
      * Renders the email element template.
      */
-    public function render_email_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'email' );
+    public function render_email_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'email');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -1086,8 +1086,8 @@ 
     /**
      * Renders the billing_email element template.
      */
-    public function render_billing_email_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'billing_email' );
+    public function render_billing_email_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'billing_email');
         $label    = "$field.label";
         echo "
             <div $restrict>
@@ -1101,24 +1101,24 @@ 
     /**
      * Renders the email element on the frontend.
      */
-    public function frontend_render_email_template( $field ) {
+    public function frontend_render_email_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'placeholder' => esc_attr($field['placeholder']),
                 'type'       => 'email',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1129,30 +1129,30 @@ 
     /**
      * Renders the billing email element on the frontend.
      */
-    public function frontend_render_billing_email_template( $field ) {
+    public function frontend_render_billing_email_template($field) {
         
         echo "<div class='form-group'>";
         $value = '';
 
-        if ( is_user_logged_in() ) {
+        if (is_user_logged_in()) {
             $user  = wp_get_current_user();
-            $value = sanitize_email( $user->user_email );
+            $value = sanitize_email($user->user_email);
         }
         echo aui()->input(
             array(
                 'name'       => 'billing_email',
                 'value'      => $value,
-                'id'         => esc_attr( $field['id'] ),
+                'id'         => esc_attr($field['id']),
                 'required'   => true,
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'placeholder' => esc_attr($field['placeholder']),
                 'type'       => 'email',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1163,16 +1163,16 @@ 
     /**
      * Renders the edit email element template.
      */
-    public function edit_email_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'email' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_email_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'email');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1200,16 +1200,16 @@ 
     /**
      * Renders the edit billing_email element template.
      */
-    public function edit_billing_email_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'billing_email' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_billing_email_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'billing_email');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1233,8 +1233,8 @@ 
     /**
      * Renders the website element template.
      */
-    public function render_website_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'website' );
+    public function render_website_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'website');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -1249,24 +1249,24 @@ 
     /**
      * Renders the website element on the frontend.
      */
-    public function frontend_render_website_template( $field ) {
+    public function frontend_render_website_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'placeholder' => esc_attr($field['placeholder']),
                 'type'       => 'url',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1277,16 +1277,16 @@ 
     /**
      * Renders the edit website element template.
      */
-    public function edit_website_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'website' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_website_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'website');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1314,8 +1314,8 @@ 
     /**
      * Renders the date element template.
      */
-    public function render_date_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'date' );
+    public function render_date_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'date');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -1330,24 +1330,24 @@ 
     /**
      * Renders the date element on the frontend.
      */
-    public function frontend_render_date_template( $field ) {
+    public function frontend_render_date_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'label'      => wp_kses_post($field['label']),
+                'placeholder' => esc_attr($field['placeholder']),
                 'no_wrap'    => true,
                 'type'       => 'date',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1358,16 +1358,16 @@ 
     /**
      * Renders the edit date element template.
      */
-    public function edit_date_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'date' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_date_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'date');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1395,8 +1395,8 @@ 
     /**
      * Renders the time element template.
      */
-    public function render_time_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'time' );
+    public function render_time_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'time');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -1411,24 +1411,24 @@ 
     /**
      * Renders the time element on the frontend.
      */
-    public function frontend_render_time_template( $field ) {
+    public function frontend_render_time_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
+                'label'      => wp_kses_post($field['label']),
                 'no_wrap'    => true,
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'placeholder' => esc_attr($field['placeholder']),
                 'type'       => 'time',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1439,16 +1439,16 @@ 
     /**
      * Renders the edit time element template.
      */
-    public function edit_time_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'time' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_time_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'time');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1476,8 +1476,8 @@ 
     /**
      * Renders the number element template.
      */
-    public function render_number_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'number' );
+    public function render_number_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'number');
         $label    = "$field.label";
         echo "
             <div $restrict class='wpinv-payment-form-field-preview'>
@@ -1492,24 +1492,24 @@ 
     /**
      * Renders the number element on the frontend.
      */
-    public function frontend_render_number_template( $field ) {
+    public function frontend_render_number_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
                 'required'   => (bool) $field['required'],
-                'label'      => wp_kses_post( $field['label'] ),
-                'placeholder' => esc_attr( $field['placeholder'] ),
+                'label'      => wp_kses_post($field['label']),
+                'placeholder' => esc_attr($field['placeholder']),
                 'no_wrap'    => true,
                 'type'       => 'number',
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1520,16 +1520,16 @@ 
     /**
      * Renders the edit number element template.
      */
-    public function edit_number_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'number' );
-        $label    = __( 'Field Label', 'invoicing' );
+    public function edit_number_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'number');
+        $label    = __('Field Label', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Placeholder text', 'invoicing' );
+        $label2   = __('Placeholder text', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label3   = __( 'Help text', 'invoicing' );
-        $label4   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label3   = __('Help text', 'invoicing');
+        $label4   = esc_attr__('Add some help text for this field', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
-        $label5   = __( 'Is this field required?', 'invoicing' );
+        $label5   = __('Is this field required?', 'invoicing');
         $id4      = $field . '.id + "_edit4"';
         echo "
             <div $restrict>
@@ -1557,23 +1557,23 @@ 
     /**
      * Renders the separator element template.
      */
-    public function render_separator_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'separator' );
+    public function render_separator_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'separator');
         echo "<hr class='featurette-divider mt-0 mb-2' $restrict>";
     }
 
     /**
      * Renders the separator element on the frontend.
      */
-    public function frontend_render_separator_template( $field ) {
+    public function frontend_render_separator_template($field) {
         echo '<hr class="featurette-divider mt-0 mb-2" />';
     }
 
     /**
      * Renders the pay button element template.
      */
-    public function render_pay_button_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'pay_button' );
+    public function render_pay_button_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'pay_button');
         $label    = "$field.label";
         echo "
             <div $restrict>
@@ -1586,28 +1586,28 @@ 
     /**
      * Renders the pay_button element on the frontend.
      */
-    public function frontend_render_pay_button_template( $field ) {
+    public function frontend_render_pay_button_template($field) {
 
         echo "<div class='mt-4 mb-4'>";
-            do_action( 'wpinv_payment_mode_select' );
+            do_action('wpinv_payment_mode_select');
         echo "</div>";
 
         echo "<div class='form-group'>";
 
-        $class = 'wpinv-payment-form-submit btn btn-block submit-button ' . sanitize_html_class( $field['class'] );
+        $class = 'wpinv-payment-form-submit btn btn-block submit-button ' . sanitize_html_class($field['class']);
         echo aui()->input(
             array(
-                'name'       => esc_attr( $field['id'] ),
-                'id'         => esc_attr( $field['id'] ),
-                'value'      => esc_attr( $field['label'] ),
+                'name'       => esc_attr($field['id']),
+                'id'         => esc_attr($field['id']),
+                'value'      => esc_attr($field['label']),
                 'no_wrap'    => true,
                 'type'       => 'submit',
                 'class'      => $class,
             )
         );
 
-        if ( ! empty( $field['description'] ) ) {
-            $description = wp_kses_post( $field['description'] );
+        if (!empty($field['description'])) {
+            $description = wp_kses_post($field['description']);
             echo "<small class='form-text text-muted'>$description</small>";
         }
 
@@ -1618,14 +1618,14 @@ 
     /**
      * Renders the pay button element template.
      */
-    public function edit_pay_button_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'pay_button' );
-        $label    = __( 'Button Text', 'invoicing' );
+    public function edit_pay_button_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'pay_button');
+        $label    = __('Button Text', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label2   = __( 'Help text', 'invoicing' );
-        $label3   = esc_attr__( 'Add some help text for this field', 'invoicing' );
+        $label2   = __('Help text', 'invoicing');
+        $label3   = esc_attr__('Add some help text for this field', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label4   = esc_attr__( 'Button Type', 'invoicing' );
+        $label4   = esc_attr__('Button Type', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
         echo "
             <div $restrict>
@@ -1641,15 +1641,15 @@ 
                     <label :for='$id3'>$label4</label>
 
                     <select class='form-control custom-select' :id='$id3' v-model='$field.class'>
-                        <option value='btn-primary'>"   . __( 'Primary', 'invoicing' ) ."</option>
-                        <option value='btn-secondary'>" . __( 'Secondary', 'invoicing' ) ."</option>
-                        <option value='btn-success'>"   . __( 'Success', 'invoicing' ) ."</option>
-                        <option value='btn-danger'>"    . __( 'Danger', 'invoicing' ) ."</option>
-                        <option value='btn-warning'>"   . __( 'Warning', 'invoicing' ) ."</option>
-                        <option value='btn-info'>"      . __( 'Info', 'invoicing' ) ."</option>
-                        <option value='btn-light'>"     . __( 'Light', 'invoicing' ) ."</option>
-                        <option value='btn-dark'>"      . __( 'Dark', 'invoicing' ) ."</option>
-                        <option value='btn-link'>"      . __( 'Link', 'invoicing' ) ."</option>
+                        <option value='btn-primary'>" . __('Primary', 'invoicing') . "</option>
+                        <option value='btn-secondary'>" . __('Secondary', 'invoicing') . "</option>
+                        <option value='btn-success'>"   . __('Success', 'invoicing') . "</option>
+                        <option value='btn-danger'>"    . __('Danger', 'invoicing') . "</option>
+                        <option value='btn-warning'>"   . __('Warning', 'invoicing') . "</option>
+                        <option value='btn-info'>"      . __('Info', 'invoicing') . "</option>
+                        <option value='btn-light'>"     . __('Light', 'invoicing') . "</option>
+                        <option value='btn-dark'>"      . __('Dark', 'invoicing') . "</option>
+                        <option value='btn-link'>"      . __('Link', 'invoicing') . "</option>
                     </select>
                 </div>
             </div>
@@ -1660,8 +1660,8 @@ 
     /**
      * Renders the alert element template.
      */
-    public function render_alert_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'alert' );
+    public function render_alert_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'alert');
         $text     = "$field.text";
         echo "
             <div $restrict class='alert' :class='$field.class' role='alert'>
@@ -1676,15 +1676,15 @@ 
     /**
      * Renders the alert element on the frontend.
      */
-    public function frontend_render_alert_template( $field ) {
+    public function frontend_render_alert_template($field) {
         
         echo "<div class='form-group'>";
 
         echo aui()->alert(
             array(
-                'content'     => wp_kses_post( $field['text'] ),
+                'content'     => wp_kses_post($field['text']),
                 'dismissible' => $field['dismissible'],
-                'type'        => str_replace( 'alert-', '', $field['class'] ),
+                'type'        => str_replace('alert-', '', $field['class']),
             )
         );
 
@@ -1695,14 +1695,14 @@ 
     /**
      * Renders the alert element template.
      */
-    public function edit_alert_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'alert' );
-        $label    = __( 'Alert Text', 'invoicing' );
-        $label2   = esc_attr__( 'Enter your alert text here', 'invoicing' );
+    public function edit_alert_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'alert');
+        $label    = __('Alert Text', 'invoicing');
+        $label2   = esc_attr__('Enter your alert text here', 'invoicing');
         $id       = $field . '.id + "_edit"';
-        $label3   = __( 'Is Dismissible?', 'invoicing' );
+        $label3   = __('Is Dismissible?', 'invoicing');
         $id2      = $field . '.id + "_edit2"';
-        $label4   = esc_attr__( 'Alert Type', 'invoicing' );
+        $label4   = esc_attr__('Alert Type', 'invoicing');
         $id3      = $field . '.id + "_edit3"';
         echo "
             <div $restrict>
@@ -1718,14 +1718,14 @@ 
                     <label :for='$id3'>$label4</label>
 
                     <select class='form-control custom-select' :id='$id3' v-model='$field.class'>
-                        <option value='alert-primary'>"   . __( 'Primary', 'invoicing' ) ."</option>
-                        <option value='alert-secondary'>" . __( 'Secondary', 'invoicing' ) ."</option>
-                        <option value='alert-success'>"   . __( 'Success', 'invoicing' ) ."</option>
-                        <option value='alert-danger'>"    . __( 'Danger', 'invoicing' ) ."</option>
-                        <option value='alert-warning'>"   . __( 'Warning', 'invoicing' ) ."</option>
-                        <option value='alert-info'>"      . __( 'Info', 'invoicing' ) ."</option>
-                        <option value='alert-light'>"     . __( 'Light', 'invoicing' ) ."</option>
-                        <option value='alert-dark'>"      . __( 'Dark', 'invoicing' ) ."</option>
+                        <option value='alert-primary'>" . __('Primary', 'invoicing') . "</option>
+                        <option value='alert-secondary'>" . __('Secondary', 'invoicing') . "</option>
+                        <option value='alert-success'>"   . __('Success', 'invoicing') . "</option>
+                        <option value='alert-danger'>"    . __('Danger', 'invoicing') . "</option>
+                        <option value='alert-warning'>"   . __('Warning', 'invoicing') . "</option>
+                        <option value='alert-info'>"      . __('Info', 'invoicing') . "</option>
+                        <option value='alert-light'>"     . __('Light', 'invoicing') . "</option>
+                        <option value='alert-dark'>"      . __('Dark', 'invoicing') . "</option>
                     </select>
                 </div>
             </div>
@@ -1736,8 +1736,8 @@ 
     /**
      * Renders the discount element template.
      */
-    public function render_discount_template( $field ) {
-        $restrict  = $this->get_restrict_markup( $field, 'discount' );
+    public function render_discount_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'discount');
         ?>
 
             <div <?php echo $restrict; ?> class="discount_field  border rounded p-3">
@@ -1754,13 +1754,13 @@ 
     /**
      * Renders the discount element on the frontend.
      */
-    public function frontend_render_discount_template( $field ) {
+    public function frontend_render_discount_template($field) {
         
-        $placeholder = esc_attr( $field['input_label'] );
-        $label       = sanitize_text_field( $field['button_label'] );
+        $placeholder = esc_attr($field['input_label']);
+        $label       = sanitize_text_field($field['button_label']);
         $description = '';
 
-        if ( ! empty( $field['description'] ) ) {
+        if (!empty($field['description'])) {
             $description = "<small class='form-text text-muted'>{$field['description']}</small>";
         }
 ?>
@@ -1781,12 +1781,12 @@ 
     /**
      * Renders the discount element template.
      */
-    public function edit_discount_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'discount' );
-        $label    = __( 'Discount Input Placeholder', 'invoicing' );
-        $label2   = __( 'Help Text', 'invoicing' );
-        $label3   = esc_attr__( 'Add some help text for this field', 'invoicing' );
-        $label4   = __( 'Button Text', 'invoicing' );
+    public function edit_discount_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'discount');
+        $label    = __('Discount Input Placeholder', 'invoicing');
+        $label2   = __('Help Text', 'invoicing');
+        $label3   = esc_attr__('Add some help text for this field', 'invoicing');
+        $label4   = __('Button Text', 'invoicing');
         $id       = $field . '.id + "_edit"';
         $id2      = $field . '.id + "_edit2"';
         $id3      = $field . '.id + "_edit3"';
@@ -1815,21 +1815,21 @@ 
     /**
      * Renders the items element template.
      */
-    public function render_items_template( $field ) {
-        $restrict  = $this->get_restrict_markup( $field, 'items' );
-        $label     = __( 'Item totals will appear here. Click to set items.', 'invoicing' );
+    public function render_items_template($field) {
+        $restrict  = $this->get_restrict_markup($field, 'items');
+        $label     = __('Item totals will appear here. Click to set items.', 'invoicing');
         echo "<div $restrict class='item_totals p-4 bg-warning text-center'>$label</div>";
     }
 
     /**
      * Renders the items element on the frontend.
      */
-    public function frontend_render_items_template( $field, $items ) {
+    public function frontend_render_items_template($field, $items) {
         
         echo "<div class='form-group item_totals'>";
         
-        $id = esc_attr( $field['id'] );
-        if ( 'total' == $field[ 'items_type' ] ) {
+        $id = esc_attr($field['id']);
+        if ('total' == $field['items_type']) {
             $total     = 0;
             $tax       = 0;
             $sub_total = 0;
@@ -1838,16 +1838,16 @@ 
             <div class="border item_totals_type_total">
 
                 <?php
-                    foreach( $items as $item ) {
+                    foreach ($items as $item) {
 
-                        $amount = floatval( $item['price'] );
+                        $amount = floatval($item['price']);
 
-                        if ( wpinv_use_taxes() ) {
+                        if (wpinv_use_taxes()) {
 
-                            $rate = wpinv_get_tax_rate( wpinv_get_default_country(), false, (int) $item['id'] );
+                            $rate = wpinv_get_tax_rate(wpinv_get_default_country(), false, (int) $item['id']);
 
-                            if ( wpinv_prices_include_tax() ) {
-                                $pre_tax  = ( $amount - $amount * $rate * 0.01 );
+                            if (wpinv_prices_include_tax()) {
+                                $pre_tax  = ($amount - $amount * $rate * 0.01);
                                 $item_tax = $amount - $pre_tax;
                             } else {
                                 $pre_tax  = $amount;
@@ -1859,27 +1859,27 @@ 
                             $total     = $sub_total + $tax;
 
                         } else {
-                            $total  = $total + $amount;
+                            $total = $total + $amount;
                         }
 
                         $class  = 'col-8';
                         $class2 = '';
 
-                        if ( ! empty( $item['allow_quantities'] ) ) {
+                        if (!empty($item['allow_quantities'])) {
                             $class = 'col-6 pt-2';
                             $class2 = 'pt-2';
                         }
 
-                        if ( ! empty( $item['custom_price'] ) ) {
+                        if (!empty($item['custom_price'])) {
                             $class .= ' pt-2';
                         }
             
                 ?>
                     <div  class="item_totals_item">
                         <div class='row pl-2 pr-2 pt-2'>
-                            <div class='<?php echo $class; ?>'><?php echo esc_html( $item['title'] ) ?></div>
+                            <div class='<?php echo $class; ?>'><?php echo esc_html($item['title']) ?></div>
 
-                            <?php  if ( ! empty( $item['allow_quantities'] ) ) { ?>
+                            <?php  if (!empty($item['allow_quantities'])) { ?>
 
                                 <div class='col-2'>
                                     <input name='wpinv-item-<?php echo (int) $item['id']; ?>-quantity' type='number' class='form-control wpinv-item-quantity-input pr-1' value='1' min='1' required>
@@ -1887,11 +1887,11 @@ 
 
                             <?php } else { ?>
                                 <input type='hidden' class='wpinv-item-quantity-input' value='1'>
-                            <?php } if ( empty( $item['custom_price'] ) ) { ?>
+                            <?php } if (empty($item['custom_price'])) { ?>
 
                                 <div class='col-4 <?php echo $class2; ?>'>
-                                    <?php echo wpinv_price( wpinv_format_amount( $item['price'] ) ) ?>
-                                    <input name='wpinv-items[<?php echo (int) $item['id']; ?>]' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval( $item['price'] ); ?>'>
+                                    <?php echo wpinv_price(wpinv_format_amount($item['price'])) ?>
+                                    <input name='wpinv-items[<?php echo (int) $item['id']; ?>]' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval($item['price']); ?>'>
                                 </div>
 
                             <?php } else {?>
@@ -1899,15 +1899,15 @@ 
                                 <div class='col-4'>
                                     <div class='input-group'>
 
-                                        <?php if ( 'left' == wpinv_currency_position() ) { ?>
+                                        <?php if ('left' == wpinv_currency_position()) { ?>
                                             <div class='input-group-prepend'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
                                         <?php } ?>
 
-                                        <input type='number' name='wpinv-items[<?php echo (int) $item['id']; ?>]' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval( $item['price'] ); ?>' value='<?php echo floatval( $item['price'] ); ?>' min='<?php echo intval( $item['minimum_price'] ); ?>'>
+                                        <input type='number' name='wpinv-items[<?php echo (int) $item['id']; ?>]' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval($item['price']); ?>' value='<?php echo floatval($item['price']); ?>' min='<?php echo intval($item['minimum_price']); ?>'>
                                     
-                                        <?php if ( 'left' != wpinv_currency_position() ) { ?>
+                                        <?php if ('left' != wpinv_currency_position()) { ?>
                                             <div class='input-group-append'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
@@ -1918,28 +1918,28 @@ 
                             <?php } ?>
 
                         </div>
-                        <?php if ( ! empty( $item['description'] )) { ?>
-                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                        <?php if (!empty($item['description'])) { ?>
+                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                         <?php } ?>
                     </div>
                 <?php } ?>
 
                 <div class='mt-4 border-top item_totals_total p-2'>
 
-                    <?php if ( wpinv_use_taxes() ) { ?>
+                    <?php if (wpinv_use_taxes()) { ?>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Sub Total', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price( wpinv_format_amount( $sub_total ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Sub Total', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price(wpinv_format_amount($sub_total)) ?></strong></div>
                         </div>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Tax', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price( wpinv_format_amount( $tax ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Tax', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price(wpinv_format_amount($tax)) ?></strong></div>
                         </div>
                     <?php } ?>
 
                     <div class='row'>
-                        <div class='col-8'><strong class='mr-5'><?php _e( 'Total', 'invoicing' ); ?></strong></div>
-                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price( wpinv_format_amount( $total ) ) ?></strong></div>
+                        <div class='col-8'><strong class='mr-5'><?php _e('Total', 'invoicing'); ?></strong></div>
+                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price(wpinv_format_amount($total)) ?></strong></div>
                     </div>
 
                 </div>
@@ -1947,22 +1947,22 @@ 
             </div>
         <?php } ?>
 
-        <?php if ( 'radio' == $field[ 'items_type' ] ) { ?>
+        <?php if ('radio' == $field['items_type']) { ?>
             <div class="item_totals_type_radio">
 
                 <?php
-                    foreach( $items as $index => $item ) {
+                    foreach ($items as $index => $item) {
 
-                        if ( ! empty( $item['required'] ) ) {
+                        if (!empty($item['required'])) {
                             continue;
                         }
                 ?>
                     <div  class="form-check">
-                        <input class='form-check-input wpinv-items-selector' <?php checked( ! isset( $selected_radio_item ) ); $selected_radio_item = 1; ?> type='radio' value='<?php echo $item['id']; ?>' id='<?php echo $id . $index; ?>' name='wpinv-payment-form-selected-item'>
-                        <label class='form-check-label' for='<?php echo $id . $index; ?>'><?php echo sanitize_text_field( $item['title'] ); ?>&nbsp;<strong><?php echo wpinv_price( wpinv_format_amount( (float) sanitize_text_field(  $item['price'] ) ) ); ?></strong></label>
+                        <input class='form-check-input wpinv-items-selector' <?php checked(!isset($selected_radio_item)); $selected_radio_item = 1; ?> type='radio' value='<?php echo $item['id']; ?>' id='<?php echo $id . $index; ?>' name='wpinv-payment-form-selected-item'>
+                        <label class='form-check-label' for='<?php echo $id . $index; ?>'><?php echo sanitize_text_field($item['title']); ?>&nbsp;<strong><?php echo wpinv_price(wpinv_format_amount((float) sanitize_text_field($item['price']))); ?></strong></label>
                     </div>
-                    <?php if ( ! empty( $item['description'] )) { ?>
-                        <small class='form-text text-muted pl-4 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                    <?php if (!empty($item['description'])) { ?>
+                        <small class='form-text text-muted pl-4 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                     <?php } ?>
                 <?php } ?>
 
@@ -1974,32 +1974,32 @@ 
                         $tax       = 0;
                         $sub_total = 0;
 
-                        foreach ( $items as $item ) {
+                        foreach ($items as $item) {
 
                             $class  = 'col-8';
                             $class2 = '';
 
-                            if ( ! empty( $item['allow_quantities'] ) ) {
+                            if (!empty($item['allow_quantities'])) {
                                 $class = 'col-6 pt-2';
                                 $class2 = 'pt-2';
                             }
 
-                            if ( ! empty( $item['custom_price'] ) ) {
+                            if (!empty($item['custom_price'])) {
                                 $class .= ' pt-2';
                             }
 
                             $class3 = 'd-none';
                             $name   = '';
-                            if ( ! empty( $item['required'] ) || ! isset( $totals_selected_radio_item ) ) {
+                            if (!empty($item['required']) || !isset($totals_selected_radio_item)) {
 
-                                $amount = floatval( $item['price'] );
+                                $amount = floatval($item['price']);
 
-                                if ( wpinv_use_taxes() ) {
+                                if (wpinv_use_taxes()) {
 
-                                    $rate = wpinv_get_tax_rate( wpinv_get_default_country(), false, (int) $item['id'] );
+                                    $rate = wpinv_get_tax_rate(wpinv_get_default_country(), false, (int) $item['id']);
 
-                                    if ( wpinv_prices_include_tax() ) {
-                                        $pre_tax  = ( $amount - $amount * $rate * 0.01 );
+                                    if (wpinv_prices_include_tax()) {
+                                        $pre_tax  = ($amount - $amount * $rate * 0.01);
                                         $item_tax = $amount - $pre_tax;
                                     } else {
                                         $pre_tax  = $amount;
@@ -2011,13 +2011,13 @@ 
                                     $total     = $sub_total + $tax;
 
                                 } else {
-                                    $total  = $total + $amount;
+                                    $total = $total + $amount;
                                 }
 
                                 $class3 = '';
                                 $name   = "wpinv-items[{$item['id']}]";
 
-                                if ( empty( $item['required'] ) ) {
+                                if (empty($item['required'])) {
                                     $totals_selected_radio_item = 1;
                                 }
 
@@ -2029,9 +2029,9 @@ 
 
                     <div  class="item_totals_item <?php echo $class3; ?>" data-id="<?php echo (int) $item['id']; ?>">
                         <div class='row pl-2 pr-2 pt-2'>
-                            <div class='<?php echo $class; ?>'><?php echo esc_html( $item['title'] ) ?></div>
+                            <div class='<?php echo $class; ?>'><?php echo esc_html($item['title']) ?></div>
 
-                            <?php  if ( ! empty( $item['allow_quantities'] ) ) { ?>
+                            <?php  if (!empty($item['allow_quantities'])) { ?>
 
                                 <div class='col-2'>
                                     <input name='wpinv-item-<?php echo (int) $item['id']; ?>-quantity' type='number' class='form-control wpinv-item-quantity-input pr-1' value='1' min='1' required>
@@ -2039,11 +2039,11 @@ 
 
                             <?php } else { ?>
                                 <input type='hidden' class='wpinv-item-quantity-input' value='1'>
-                            <?php } if ( empty( $item['custom_price'] ) ) { ?>
+                            <?php } if (empty($item['custom_price'])) { ?>
 
                                 <div class='col-4 <?php echo $class2; ?>'>
-                                    <?php echo wpinv_price( wpinv_format_amount( $item['price'] ) ) ?>
-                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval( $item['price'] ); ?>'>
+                                    <?php echo wpinv_price(wpinv_format_amount($item['price'])) ?>
+                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval($item['price']); ?>'>
                                 </div>
 
                             <?php } else {?>
@@ -2051,15 +2051,15 @@ 
                                 <div class='col-4'>
                                     <div class='input-group'>
 
-                                        <?php if ( 'left' == wpinv_currency_position() ) { ?>
+                                        <?php if ('left' == wpinv_currency_position()) { ?>
                                             <div class='input-group-prepend'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
                                         <?php } ?>
 
-                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval( $item['price'] ); ?>' value='<?php echo floatval( $item['price'] ); ?>' min='<?php echo intval( $item['minimum_price'] ); ?>'>
+                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval($item['price']); ?>' value='<?php echo floatval($item['price']); ?>' min='<?php echo intval($item['minimum_price']); ?>'>
                                     
-                                        <?php if ( 'left' != wpinv_currency_position() ) { ?>
+                                        <?php if ('left' != wpinv_currency_position()) { ?>
                                             <div class='input-group-append'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
@@ -2070,27 +2070,27 @@ 
                             <?php } ?>
 
                         </div>
-                        <?php if ( ! empty( $item['description'] )) { ?>
-                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                        <?php if (!empty($item['description'])) { ?>
+                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                         <?php } ?>
                     </div>
                 <?php } ?>
 
                 <div class='mt-4 border-top item_totals_total p-2'>
-                    <?php if ( wpinv_use_taxes() ) { ?>
+                    <?php if (wpinv_use_taxes()) { ?>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Sub Total', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price( wpinv_format_amount( $sub_total ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Sub Total', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price(wpinv_format_amount($sub_total)) ?></strong></div>
                         </div>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Tax', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price( wpinv_format_amount( $tax ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Tax', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price(wpinv_format_amount($tax)) ?></strong></div>
                         </div>
                     <?php } ?>
 
                     <div class='row'>
-                        <div class='col-8'><strong class='mr-5'><?php _e( 'Total', 'invoicing' ); ?></strong></div>
-                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price( wpinv_format_amount( $total ) ) ?></strong></div>
+                        <div class='col-8'><strong class='mr-5'><?php _e('Total', 'invoicing'); ?></strong></div>
+                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price(wpinv_format_amount($total)) ?></strong></div>
                     </div>
                 </div>
 
@@ -2098,22 +2098,22 @@ 
             </div>
         <?php } ?>
 
-        <?php if ( 'checkbox' == $field[ 'items_type' ] ) { ?>
+        <?php if ('checkbox' == $field['items_type']) { ?>
 
             <div class="item_totals_type_checkbox">
 
                 <?php
-                    foreach ( $items as $index => $item ) {
+                    foreach ($items as $index => $item) {
 
-                        if ( ! empty( $item['required'] ) ) {
+                        if (!empty($item['required'])) {
                             continue;
                         }
 
-                        $title = sanitize_text_field(  $item['title'] );
-                        $price = wpinv_price( wpinv_format_amount( (float) sanitize_text_field(  $item['price'] ) ) );
-                        $item_id    = esc_attr( $id . "_$index" );
-                        $value = esc_attr( $item['id'] );
-                        $checked = checked( ! isset( $selected_checkbox_item ), true, false );
+                        $title = sanitize_text_field($item['title']);
+                        $price = wpinv_price(wpinv_format_amount((float) sanitize_text_field($item['price'])));
+                        $item_id = esc_attr($id . "_$index");
+                        $value = esc_attr($item['id']);
+                        $checked = checked(!isset($selected_checkbox_item), true, false);
                         $selected_checkbox_item = 1;
 
                         echo "
@@ -2122,7 +2122,7 @@ 
                                 <label for='$item_id' class='custom-control-label'>$title &nbsp; ($price)</label>
                             </div>";
 
-                        if ( ! empty( $item['description'] ) ) {
+                        if (!empty($item['description'])) {
                             echo "<small class='form-text text-muted'>{$item['description']}</small>";
                         }
                     }
@@ -2136,31 +2136,31 @@ 
                         $tax       = 0;
                         $sub_total = 0;
 
-                        foreach ( $items as $item ) {
+                        foreach ($items as $item) {
 
                             $class  = 'col-8';
                             $class2 = '';
 
-                            if ( ! empty( $item['allow_quantities'] ) ) {
+                            if (!empty($item['allow_quantities'])) {
                                 $class = 'col-6 pt-2';
                                 $class2 = 'pt-2';
                             }
 
-                            if ( ! empty( $item['custom_price'] ) ) {
+                            if (!empty($item['custom_price'])) {
                                 $class .= ' pt-2';
                             }
 
                             $class3 = 'd-none';
-                            $name  = '';
-                            if ( ! empty( $item['required'] ) || ! isset( $totals_selected_checkbox_item ) ) {
+                            $name = '';
+                            if (!empty($item['required']) || !isset($totals_selected_checkbox_item)) {
 
-                                $amount = floatval( $item['price'] );
-                                if ( wpinv_use_taxes() ) {
+                                $amount = floatval($item['price']);
+                                if (wpinv_use_taxes()) {
 
-                                    $rate = wpinv_get_tax_rate( wpinv_get_default_country(), false, (int) $item['id'] );
+                                    $rate = wpinv_get_tax_rate(wpinv_get_default_country(), false, (int) $item['id']);
 
-                                    if ( wpinv_prices_include_tax() ) {
-                                        $pre_tax  = ( $amount - $amount * $rate * 0.01 );
+                                    if (wpinv_prices_include_tax()) {
+                                        $pre_tax  = ($amount - $amount * $rate * 0.01);
                                         $item_tax = $amount - $pre_tax;
                                     } else {
                                         $pre_tax  = $amount;
@@ -2172,13 +2172,13 @@ 
                                     $total     = $sub_total + $tax;
 
                                 } else {
-                                    $total  = $total + $amount;
+                                    $total = $total + $amount;
                                 }
 
                                 $class3 = '';
-                                $name  = "wpinv-items[{$item['id']}]";
+                                $name = "wpinv-items[{$item['id']}]";
 
-                                if ( empty( $item['required'] ) ) {
+                                if (empty($item['required'])) {
                                     $totals_selected_checkbox_item = 1;
                                 }
 
@@ -2190,9 +2190,9 @@ 
 
                     <div  class="item_totals_item <?php echo $class3; ?>" data-id="<?php echo (int) $item['id']; ?>">
                         <div class='row pl-2 pr-2 pt-2'>
-                            <div class='<?php echo $class; ?>'><?php echo esc_html( $item['title'] ) ?></div>
+                            <div class='<?php echo $class; ?>'><?php echo esc_html($item['title']) ?></div>
 
-                            <?php  if ( ! empty( $item['allow_quantities'] ) ) { ?>
+                            <?php  if (!empty($item['allow_quantities'])) { ?>
 
                                 <div class='col-2'>
                                     <input name='wpinv-item-<?php echo (int) $item['id']; ?>-quantity' type='number' class='form-control wpinv-item-quantity-input pr-1' value='1' min='1' required>
@@ -2200,11 +2200,11 @@ 
 
                             <?php } else { ?>
                                 <input type='hidden' class='wpinv-item-quantity-input' value='1'>
-                            <?php } if ( empty( $item['custom_price'] ) ) { ?>
+                            <?php } if (empty($item['custom_price'])) { ?>
 
                                 <div class='col-4 <?php echo $class2; ?>'>
-                                    <?php echo wpinv_price( wpinv_format_amount( $item['price'] ) ) ?>
-                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval( $item['price'] ); ?>'>
+                                    <?php echo wpinv_price(wpinv_format_amount($item['price'])) ?>
+                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval($item['price']); ?>'>
                                 </div>
 
                             <?php } else {?>
@@ -2212,15 +2212,15 @@ 
                                 <div class='col-4'>
                                     <div class='input-group'>
 
-                                        <?php if ( 'left' == wpinv_currency_position() ) { ?>
+                                        <?php if ('left' == wpinv_currency_position()) { ?>
                                             <div class='input-group-prepend'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
                                         <?php } ?>
 
-                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval( $item['price'] ); ?>' value='<?php echo floatval( $item['price'] ); ?>' min='<?php echo intval( $item['minimum_price'] ); ?>'>
+                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval($item['price']); ?>' value='<?php echo floatval($item['price']); ?>' min='<?php echo intval($item['minimum_price']); ?>'>
                                     
-                                        <?php if ( 'left' != wpinv_currency_position() ) { ?>
+                                        <?php if ('left' != wpinv_currency_position()) { ?>
                                             <div class='input-group-append'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
@@ -2231,35 +2231,35 @@ 
                             <?php } ?>
 
                         </div>
-                        <?php if ( ! empty( $item['description'] )) { ?>
-                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                        <?php if (!empty($item['description'])) { ?>
+                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                         <?php } ?>
                     </div>
                 <?php } ?>
 
                 <div class='mt-4 border-top item_totals_total p-2'>
 
-                    <?php if ( wpinv_use_taxes() ) { ?>
+                    <?php if (wpinv_use_taxes()) { ?>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Sub Total', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price( wpinv_format_amount( $sub_total ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Sub Total', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price(wpinv_format_amount($sub_total)) ?></strong></div>
                         </div>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Tax', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price( wpinv_format_amount( $tax ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Tax', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price(wpinv_format_amount($tax)) ?></strong></div>
                         </div>
                     <?php } ?>
 
                     <div class='row'>
-                        <div class='col-8'><strong class='mr-5'><?php _e( 'Total', 'invoicing' ); ?></strong></div>
-                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price( wpinv_format_amount( $total ) ) ?></strong></div>
+                        <div class='col-8'><strong class='mr-5'><?php _e('Total', 'invoicing'); ?></strong></div>
+                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price(wpinv_format_amount($total)) ?></strong></div>
                     </div>
                 </div>
             </div>
             </div>
         <?php } ?>
 
-        <?php if ( 'select' == $field[ 'items_type' ] ) { ?>
+        <?php if ('select' == $field['items_type']) { ?>
 
             <div class="item_totals_type_select">
 
@@ -2267,17 +2267,17 @@ 
 
                     $options  = array();
                     $selected = '';
-                    foreach ( $items as $index => $item ) {
+                    foreach ($items as $index => $item) {
 
-                        if ( ! empty( $item['required'] ) ) {
+                        if (!empty($item['required'])) {
                             continue;
                         }
 
-                        $title = sanitize_text_field(  $item['title'] );
-                        $price = wpinv_price( wpinv_format_amount( (float) sanitize_text_field(  $item['price'] ) ) );
-                        $options[ $item['id'] ] = "$title &nbsp; ($price)";
+                        $title = sanitize_text_field($item['title']);
+                        $price = wpinv_price(wpinv_format_amount((float) sanitize_text_field($item['price'])));
+                        $options[$item['id']] = "$title &nbsp; ($price)";
 
-                        if ( ! isset( $selected_item ) ) {
+                        if (!isset($selected_item)) {
                             $selected = $item['id'];
                             $selected_item = 1;
                         }
@@ -2288,7 +2288,7 @@ 
                         array(
                                 'name'        => 'payment-form-items',
                                 'id'          => $id,
-                                'placeholder' => __( 'Select an item', 'invoicing' ),
+                                'placeholder' => __('Select an item', 'invoicing'),
                                 'no_wrap'     => true,
                                 'options'     => $options,
                                 'class'       => 'wpi_select2 wpinv-items-select-selector',
@@ -2305,31 +2305,31 @@ 
                         $tax       = 0;
                         $sub_total = 0;
 
-                        foreach ( $items as $item ) {
+                        foreach ($items as $item) {
 
                             $class  = 'col-8';
                             $class2 = '';
 
-                            if ( ! empty( $item['allow_quantities'] ) ) {
+                            if (!empty($item['allow_quantities'])) {
                                 $class = 'col-6 pt-2';
                                 $class2 = 'pt-2';
                             }
 
-                            if ( ! empty( $item['custom_price'] ) ) {
+                            if (!empty($item['custom_price'])) {
                                 $class .= ' pt-2';
                             }
 
                             $class3 = 'd-none';
-                            $name  = '';
-                            if ( ! empty( $item['required'] ) || ! isset( $totals_selected_select_item ) ) {
+                            $name = '';
+                            if (!empty($item['required']) || !isset($totals_selected_select_item)) {
 
-                                $amount = floatval( $item['price'] );
-                                if ( wpinv_use_taxes() ) {
+                                $amount = floatval($item['price']);
+                                if (wpinv_use_taxes()) {
 
-                                    $rate = wpinv_get_tax_rate( wpinv_get_default_country(), false, (int) $item['id'] );
+                                    $rate = wpinv_get_tax_rate(wpinv_get_default_country(), false, (int) $item['id']);
 
-                                    if ( wpinv_prices_include_tax() ) {
-                                        $pre_tax  = ( $amount - $amount * $rate * 0.01 );
+                                    if (wpinv_prices_include_tax()) {
+                                        $pre_tax  = ($amount - $amount * $rate * 0.01);
                                         $item_tax = $amount - $pre_tax;
                                     } else {
                                         $pre_tax  = $amount;
@@ -2341,13 +2341,13 @@ 
                                     $total     = $sub_total + $tax;
 
                                 } else {
-                                    $total  = $total + $amount;
+                                    $total = $total + $amount;
                                 }
 
                                 $class3 = '';
-                                $name  = "wpinv-items[{$item['id']}]";
+                                $name = "wpinv-items[{$item['id']}]";
 
-                                if ( empty( $item['required'] ) ) {
+                                if (empty($item['required'])) {
                                     $totals_selected_select_item = 1;
                                 }
 
@@ -2359,9 +2359,9 @@ 
 
                     <div  class="item_totals_item <?php echo $class3; ?>" data-id="<?php echo (int) $item['id']; ?>">
                         <div class='row pl-2 pr-2 pt-2'>
-                            <div class='<?php echo $class; ?>'><?php echo esc_html( $item['title'] ) ?></div>
+                            <div class='<?php echo $class; ?>'><?php echo esc_html($item['title']) ?></div>
 
-                            <?php  if ( ! empty( $item['allow_quantities'] ) ) { ?>
+                            <?php  if (!empty($item['allow_quantities'])) { ?>
 
                                 <div class='col-2'>
                                     <input name='wpinv-item-<?php echo (int) $item['id']; ?>-quantity' type='number' class='form-control wpinv-item-quantity-input pr-1' value='1' min='1' required>
@@ -2369,11 +2369,11 @@ 
 
                             <?php } else { ?>
                                 <input type='hidden' class='wpinv-item-quantity-input' value='1'>
-                            <?php } if ( empty( $item['custom_price'] ) ) { ?>
+                            <?php } if (empty($item['custom_price'])) { ?>
 
                                 <div class='col-4 <?php echo $class2; ?>'>
-                                    <?php echo wpinv_price( wpinv_format_amount( $item['price'] ) ) ?>
-                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval( $item['price'] ); ?>'>
+                                    <?php echo wpinv_price(wpinv_format_amount($item['price'])) ?>
+                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval($item['price']); ?>'>
                                 </div>
 
                             <?php } else {?>
@@ -2381,15 +2381,15 @@ 
                                 <div class='col-4'>
                                     <div class='input-group'>
 
-                                        <?php if ( 'left' == wpinv_currency_position() ) { ?>
+                                        <?php if ('left' == wpinv_currency_position()) { ?>
                                             <div class='input-group-prepend'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
                                         <?php } ?>
 
-                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval( $item['price'] ); ?>' value='<?php echo floatval( $item['price'] ); ?>' min='<?php echo intval( $item['minimum_price'] ); ?>'>
+                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval($item['price']); ?>' value='<?php echo floatval($item['price']); ?>' min='<?php echo intval($item['minimum_price']); ?>'>
                                     
-                                        <?php if ( 'left' != wpinv_currency_position() ) { ?>
+                                        <?php if ('left' != wpinv_currency_position()) { ?>
                                             <div class='input-group-append'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
@@ -2400,34 +2400,34 @@ 
                             <?php } ?>
 
                         </div>
-                        <?php if ( ! empty( $item['description'] )) { ?>
-                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                        <?php if (!empty($item['description'])) { ?>
+                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                         <?php } ?>
                     </div>
                 <?php } ?>
 
                 <div class='mt-4 border-top item_totals_total p-2'>
 
-                    <?php if ( wpinv_use_taxes() ) { ?>
+                    <?php if (wpinv_use_taxes()) { ?>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Sub Total', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price( wpinv_format_amount( $sub_total ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Sub Total', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price(wpinv_format_amount($sub_total)) ?></strong></div>
                         </div>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Tax', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price( wpinv_format_amount( $tax ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Tax', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price(wpinv_format_amount($tax)) ?></strong></div>
                         </div>
                     <?php } ?>
                     <div class='row'>
-                        <div class='col-8'><strong class='mr-5'><?php _e( 'Total', 'invoicing' ); ?></strong></div>
-                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price( wpinv_format_amount( $total ) ) ?></strong></div>
+                        <div class='col-8'><strong class='mr-5'><?php _e('Total', 'invoicing'); ?></strong></div>
+                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price(wpinv_format_amount($total)) ?></strong></div>
                     </div>
                 </div>
 
             </div>
         <?php } ?>
 
-        <?php if ( 'multi_select' == $field[ 'items_type' ] ) { ?>
+        <?php if ('multi_select' == $field['items_type']) { ?>
 
             <div class="item_totals_type_multi_select">
 
@@ -2436,18 +2436,18 @@ 
                     $options  = array();
                     $selected = array();
 
-                    foreach ( $items as $index => $item ) {
+                    foreach ($items as $index => $item) {
 
-                        if ( ! empty( $item['required'] ) ) {
+                        if (!empty($item['required'])) {
                             continue;
                         }
 
-                        $title = sanitize_text_field(  $item['title'] );
-                        $price = wpinv_price( wpinv_format_amount( (float) sanitize_text_field(  $item['price'] ) ) );
-                        $options[ $item['id'] ] = "$title &nbsp; ($price)";
+                        $title = sanitize_text_field($item['title']);
+                        $price = wpinv_price(wpinv_format_amount((float) sanitize_text_field($item['price'])));
+                        $options[$item['id']] = "$title &nbsp; ($price)";
 
-                        if ( ! isset( $selected_item ) ) {
-                            $selected = array( $item['id'] );
+                        if (!isset($selected_item)) {
+                            $selected = array($item['id']);
                             $selected_item = 1;
                         }
 
@@ -2474,31 +2474,31 @@ 
                         $tax       = 0;
                         $sub_total = 0;
 
-                        foreach ( $items as $item ) {
+                        foreach ($items as $item) {
 
                             $class  = 'col-8';
                             $class2 = '';
 
-                            if ( ! empty( $item['allow_quantities'] ) ) {
+                            if (!empty($item['allow_quantities'])) {
                                 $class = 'col-6 pt-2';
                                 $class2 = 'pt-2';
                             }
 
-                            if ( ! empty( $item['custom_price'] ) ) {
+                            if (!empty($item['custom_price'])) {
                                 $class .= ' pt-2';
                             }
 
                             $class3 = 'd-none';
-                            $name  = '';
-                            if ( ! empty( $item['required'] ) || ! isset( $totals_selected_select_item ) ) {
+                            $name = '';
+                            if (!empty($item['required']) || !isset($totals_selected_select_item)) {
 
-                                $amount = floatval( $item['price'] );
-                                if ( wpinv_use_taxes() ) {
+                                $amount = floatval($item['price']);
+                                if (wpinv_use_taxes()) {
 
-                                    $rate = wpinv_get_tax_rate( wpinv_get_default_country(), false, (int) $item['id'] );
+                                    $rate = wpinv_get_tax_rate(wpinv_get_default_country(), false, (int) $item['id']);
 
-                                    if ( wpinv_prices_include_tax() ) {
-                                        $pre_tax  = ( $amount - $amount * $rate * 0.01 );
+                                    if (wpinv_prices_include_tax()) {
+                                        $pre_tax  = ($amount - $amount * $rate * 0.01);
                                         $item_tax = $amount - $pre_tax;
                                     } else {
                                         $pre_tax  = $amount;
@@ -2510,13 +2510,13 @@ 
                                     $total     = $sub_total + $tax;
 
                                 } else {
-                                    $total  = $total + $amount;
+                                    $total = $total + $amount;
                                 }
 
                                 $class3 = '';
-                                $name  = "wpinv-items[{$item['id']}]";
+                                $name = "wpinv-items[{$item['id']}]";
 
-                                if ( empty( $item['required'] ) ) {
+                                if (empty($item['required'])) {
                                     $totals_selected_select_item = 1;
                                 }
 
@@ -2528,9 +2528,9 @@ 
 
                     <div  class="item_totals_item <?php echo $class3; ?>" data-id="<?php echo (int) $item['id']; ?>">
                         <div class='row pl-2 pr-2 pt-2'>
-                            <div class='<?php echo $class; ?>'><?php echo esc_html( $item['title'] ) ?></div>
+                            <div class='<?php echo $class; ?>'><?php echo esc_html($item['title']) ?></div>
 
-                            <?php  if ( ! empty( $item['allow_quantities'] ) ) { ?>
+                            <?php  if (!empty($item['allow_quantities'])) { ?>
 
                                 <div class='col-2'>
                                     <input name='wpinv-item-<?php echo (int) $item['id']; ?>-quantity' type='number' class='form-control wpinv-item-quantity-input pr-1' value='1' min='1' required>
@@ -2538,11 +2538,11 @@ 
 
                             <?php } else { ?>
                                 <input type='hidden' class='wpinv-item-quantity-input' value='1'>
-                            <?php } if ( empty( $item['custom_price'] ) ) { ?>
+                            <?php } if (empty($item['custom_price'])) { ?>
 
                                 <div class='col-4 <?php echo $class2; ?>'>
-                                    <?php echo wpinv_price( wpinv_format_amount( $item['price'] ) ) ?>
-                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval( $item['price'] ); ?>'>
+                                    <?php echo wpinv_price(wpinv_format_amount($item['price'])) ?>
+                                    <input name='<?php echo $name; ?>' type='hidden' class='wpinv-item-price-input' value='<?php echo floatval($item['price']); ?>'>
                                 </div>
 
                             <?php } else {?>
@@ -2550,15 +2550,15 @@ 
                                 <div class='col-4'>
                                     <div class='input-group'>
 
-                                        <?php if ( 'left' == wpinv_currency_position() ) { ?>
+                                        <?php if ('left' == wpinv_currency_position()) { ?>
                                             <div class='input-group-prepend'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
                                         <?php } ?>
 
-                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval( $item['price'] ); ?>' value='<?php echo floatval( $item['price'] ); ?>' min='<?php echo intval( $item['minimum_price'] ); ?>'>
+                                        <input type='number' name='<?php echo $name; ?>' class='form-control wpinv-item-price-input' placeholder='<?php echo floatval($item['price']); ?>' value='<?php echo floatval($item['price']); ?>' min='<?php echo intval($item['minimum_price']); ?>'>
                                     
-                                        <?php if ( 'left' != wpinv_currency_position() ) { ?>
+                                        <?php if ('left' != wpinv_currency_position()) { ?>
                                             <div class='input-group-append'>
                                                 <span class='input-group-text'><?php echo wpinv_currency_symbol(); ?></span>
                                             </div>
@@ -2569,35 +2569,35 @@ 
                             <?php } ?>
 
                         </div>
-                        <?php if ( ! empty( $item['description'] )) { ?>
-                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post( $item['description'] ); ?></small>
+                        <?php if (!empty($item['description'])) { ?>
+                            <small class='form-text text-muted pl-2 pr-2 m-0'><?php echo wp_kses_post($item['description']); ?></small>
                         <?php } ?>
                     </div>
                 <?php } ?>
 
                 <div class='mt-4 border-top item_totals_total p-2'>
 
-                    <?php if ( wpinv_use_taxes() ) { ?>
+                    <?php if (wpinv_use_taxes()) { ?>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Sub Total', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price( wpinv_format_amount( $sub_total ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Sub Total', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-sub-total'><?php echo wpinv_price(wpinv_format_amount($sub_total)) ?></strong></div>
                         </div>
                         <div class='row'>
-                            <div class='col-8'><strong class='mr-5'><?php _e( 'Tax', 'invoicing' ); ?></strong></div>
-                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price( wpinv_format_amount( $tax ) ) ?></strong></div>
+                            <div class='col-8'><strong class='mr-5'><?php _e('Tax', 'invoicing'); ?></strong></div>
+                            <div class='col-4'><strong class='wpinv-items-tax' ><?php echo wpinv_price(wpinv_format_amount($tax)) ?></strong></div>
                         </div>
                     <?php } ?>
 
                     <div class='row'>
-                        <div class='col-8'><strong class='mr-5'><?php _e( 'Total', 'invoicing' ); ?></strong></div>
-                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price( wpinv_format_amount( $total ) ) ?></strong></div>
+                        <div class='col-8'><strong class='mr-5'><?php _e('Total', 'invoicing'); ?></strong></div>
+                        <div class='col-4'><strong class='wpinv-items-total' data-currency='<?php echo wpinv_currency_symbol(); ?>' data-currency-position='<?php echo wpinv_currency_position(); ?>'><?php echo wpinv_price(wpinv_format_amount($total)) ?></strong></div>
                     </div>
                 </div>
 
             </div>
         <?php } ?>
-        <?php if ( ! empty( $field[ 'description' ] ) ) { ?>
-            <small class='form-text text-muted'><?php echo wp_kses_post( $field[ 'description' ] ); ?></small>
+        <?php if (!empty($field['description'])) { ?>
+            <small class='form-text text-muted'><?php echo wp_kses_post($field['description']); ?></small>
         <?php } ?>
         </div>
         <?php
@@ -2606,20 +2606,20 @@ 
     /**
      * Renders the items element template.
      */
-    public function edit_items_template( $field ) {
-        $restrict = $this->get_restrict_markup( $field, 'items' );
-        $label    = __( 'Let customers...', 'invoicing' );
-        $label2   = __( 'Available Items', 'invoicing' );
-        $label3   = esc_attr__( 'Add some help text for this element', 'invoicing' );
+    public function edit_items_template($field) {
+        $restrict = $this->get_restrict_markup($field, 'items');
+        $label    = __('Let customers...', 'invoicing');
+        $label2   = __('Available Items', 'invoicing');
+        $label3   = esc_attr__('Add some help text for this element', 'invoicing');
         $id       = $field . '.id + "_edit"';
         $id2      = $field . '.id + "_edit2"';
         $id3      = $field . '.id + "_edit3"';
         $id4      = $field . '.id + "_edit4"';
-        $label4   = esc_attr__( 'This will be shown to the customer as the recommended price', 'invoicing' );
-        $label5   = esc_attr__( 'Allow users to pay what they want', 'invoicing' );
-        $label6   = esc_attr__( 'Enter the minimum price that a user can pay', 'invoicing' );
-        $label7   = esc_attr__( 'Allow users to buy several quantities', 'invoicing' );
-        $label8   = esc_attr__( 'This item is required', 'invoicing' );
+        $label4   = esc_attr__('This will be shown to the customer as the recommended price', 'invoicing');
+        $label5   = esc_attr__('Allow users to pay what they want', 'invoicing');
+        $label6   = esc_attr__('Enter the minimum price that a user can pay', 'invoicing');
+        $label7   = esc_attr__('Allow users to buy several quantities', 'invoicing');
+        $label8   = esc_attr__('This item is required', 'invoicing');
         echo "<div $restrict>
 
                 <label>$label2</label>
@@ -2689,7 +2689,7 @@ 
                 <div class='form-group mt-2'>
 
                     <select class='form-control custom-select' v-model='selected_item' @change='addSelectedItem'>
-                        <option value=''>"        . __( 'Add an existing item to the form', 'invoicing' ) ."</option>
+                        <option value=''>" . __('Add an existing item to the form', 'invoicing') . "</option>
                         <option v-for='(item, index) in all_items' :value='index'>{{item.title}}</option>
                     </select>
 
@@ -2704,11 +2704,11 @@ 
                     <label :for='$id2'>$label</label>
 
                     <select class='form-control custom-select' :id='$id2' v-model='$field.items_type'>
-                        <option value='total'>"        . __( 'Buy all items on the list', 'invoicing' ) ."</option>
-                        <option value='radio'>"        . __( 'Select a single item from the list', 'invoicing' ) ."</option>
-                        <option value='checkbox'>"     . __( 'Select one or more items on the list', 'invoicing' ) ."</option>
-                        <option value='select'>"       . __( 'Select a single item from a dropdown', 'invoicing' ) ."</option>
-                        <option value='multi_select'>" . __( 'Select a one or more items from a dropdown', 'invoicing' ) ."</option>
+                        <option value='total'>" . __('Buy all items on the list', 'invoicing') . "</option>
+                        <option value='radio'>"        . __('Select a single item from the list', 'invoicing') . "</option>
+                        <option value='checkbox'>"     . __('Select one or more items on the list', 'invoicing') . "</option>
+                        <option value='select'>"       . __('Select a single item from a dropdown', 'invoicing') . "</option>
+                        <option value='multi_select'>" . __('Select a one or more items from a dropdown', 'invoicing') . "</option>
                     </select>
 
                 </div>
@@ -2733,7 +2733,7 @@ 
             'orderby'        => 'title',
             'order'          => 'ASC',
             'posts_per_page' => -1,
-            'post_status'    => array( 'publish' ),
+            'post_status'    => array('publish'),
             'meta_query'     => array(
                 array(
                     'key'       => '_wpinv_type',
@@ -2743,24 +2743,24 @@ 
             )
         );
     
-        $items = get_posts( apply_filters( 'wpinv_payment_form_item_dropdown_query_args', $item_args ) );
+        $items = get_posts(apply_filters('wpinv_payment_form_item_dropdown_query_args', $item_args));
 
-        if ( empty( $items ) ) {
+        if (empty($items)) {
             return array();
         }
 
-        $options    = array();
-        foreach ( $items as $item ) {
-            $title            = esc_html( $item->post_title );
-            $title           .= wpinv_get_item_suffix( $item->ID, false );
-            $id               = absint( $item->ID );
-            $price            = wpinv_sanitize_amount( get_post_meta( $id, '_wpinv_price', true ) );
-            $recurring        = (bool) get_post_meta( $id, '_wpinv_is_recurring', true );
+        $options = array();
+        foreach ($items as $item) {
+            $title            = esc_html($item->post_title);
+            $title           .= wpinv_get_item_suffix($item->ID, false);
+            $id               = absint($item->ID);
+            $price            = wpinv_sanitize_amount(get_post_meta($id, '_wpinv_price', true));
+            $recurring        = (bool) get_post_meta($id, '_wpinv_is_recurring', true);
             $description      = $item->post_excerpt;
-            $custom_price     = (bool) get_post_meta( $id, '_wpinv_dynamic_pricing', true );
-            $minimum_price    = (float) get_post_meta( $id, '_minimum_price', true );
+            $custom_price     = (bool) get_post_meta($id, '_wpinv_dynamic_pricing', true);
+            $minimum_price    = (float) get_post_meta($id, '_minimum_price', true);
             $allow_quantities = false;
-            $options[]        = compact( 'title', 'id', 'price', 'recurring', 'description', 'custom_price', 'minimum_price', 'allow_quantities' );
+            $options[]        = compact('title', 'id', 'price', 'recurring', 'description', 'custom_price', 'minimum_price', 'allow_quantities');
 
         }
         return $options;
@@ -2770,47 +2770,47 @@ 
     /**
      * Returns an array of items for the currently being edited form.
      */
-    public function get_form_items( $id = false ) {
+    public function get_form_items($id = false) {
         
-        if ( empty( $id ) ) {
-            return wpinv_get_data( 'sample-payment-form-items' );
+        if (empty($id)) {
+            return wpinv_get_data('sample-payment-form-items');
         }
         
-        $form_elements = get_post_meta( $id, 'wpinv_form_items', true );
+        $form_elements = get_post_meta($id, 'wpinv_form_items', true);
 
-        if ( is_array( $form_elements ) ) {
+        if (is_array($form_elements)) {
             return $form_elements;
         }
 
-        return wpinv_get_data( 'sample-payment-form-items' );
+        return wpinv_get_data('sample-payment-form-items');
 
     }
 
     /**
      * Returns an array of elements for the currently being edited form.
      */
-    public function get_form_elements( $id = false ) {
+    public function get_form_elements($id = false) {
 
-        if ( empty( $id ) ) {
-            return wpinv_get_data( 'sample-payment-form' );
+        if (empty($id)) {
+            return wpinv_get_data('sample-payment-form');
         }
         
-        $form_elements = get_post_meta( $id, 'wpinv_form_elements', true );
+        $form_elements = get_post_meta($id, 'wpinv_form_elements', true);
 
-        if ( is_array( $form_elements ) ) {
+        if (is_array($form_elements)) {
             return $form_elements;
         }
 
-        return wpinv_get_data( 'sample-payment-form' );
+        return wpinv_get_data('sample-payment-form');
     }
 
     /**
      * Sends a redrect response to payment details.
      *
      */
-    public function send_redirect_response( $url ) {
-        $url = urlencode( $url );
-        wp_send_json_success( $url );
+    public function send_redirect_response($url) {
+        $url = urlencode($url);
+        wp_send_json_success($url);
     }
 
     /**
@@ -2821,12 +2821,12 @@ 
 
         $errors = wpinv_get_errors();
 
-        if ( ! empty( $errors ) ) {
+        if (!empty($errors)) {
             wpinv_print_errors();
             exit;
         }
 
-        wp_send_json_error( __( 'An error occured while processing your payment. Please try again.', 'invoicing' ) );
+        wp_send_json_error(__('An error occured while processing your payment. Please try again.', 'invoicing'));
         exit;
 
     }