AyeCode / invoicing

includes/payments/class-getpaid-checkout.php

Indentation +297 added lines, -297 removed lines

@@ -12,180 +12,180 @@ 
  */
 class GetPaid_Checkout {
 
-	/**
-	 * @var GetPaid_Payment_Form_Submission
-	 */
-	protected $payment_form_submission;
-
-	/**
-	 * Class constructor.
-	 * 
-	 * @param GetPaid_Payment_Form_Submission $submission
-	 */
-	public function __construct( $submission ) {
-		$this->payment_form_submission = $submission;
-	}
-
-	/**
-	 * Processes the checkout.
-	 *
-	 */
-	public function process_checkout() {
-
-		// Validate the submission.
-		$this->validate_submission();
-
-		// Prepare the invoice.
-		$items      = $this->get_submission_items();
-		$invoice    = $this->get_submission_invoice();
-		$invoice    = $this->process_submission_invoice( $invoice, $items );
-		$prepared   = $this->prepare_submission_data_for_saving();
-
-		$this->prepare_billing_info( $invoice );
-
-		$shipping   = $this->prepare_shipping_info( $invoice );
-
-		// Save the invoice.
-		$invoice->set_is_viewed( true );
-		$invoice->recalculate_total();
+    /**
+     * @var GetPaid_Payment_Form_Submission
+     */
+    protected $payment_form_submission;
+
+    /**
+     * Class constructor.
+     * 
+     * @param GetPaid_Payment_Form_Submission $submission
+     */
+    public function __construct( $submission ) {
+        $this->payment_form_submission = $submission;
+    }
+
+    /**
+     * Processes the checkout.
+     *
+     */
+    public function process_checkout() {
+
+        // Validate the submission.
+        $this->validate_submission();
+
+        // Prepare the invoice.
+        $items      = $this->get_submission_items();
+        $invoice    = $this->get_submission_invoice();
+        $invoice    = $this->process_submission_invoice( $invoice, $items );
+        $prepared   = $this->prepare_submission_data_for_saving();
+
+        $this->prepare_billing_info( $invoice );
+
+        $shipping   = $this->prepare_shipping_info( $invoice );
+
+        // Save the invoice.
+        $invoice->set_is_viewed( true );
+        $invoice->recalculate_total();
         $invoice->save();
 
-		do_action( 'getpaid_checkout_invoice_updated', $invoice );
+        do_action( 'getpaid_checkout_invoice_updated', $invoice );
 
-		// Send to the gateway.
-		$this->post_process_submission( $invoice, $prepared, $shipping );
-	}
+        // Send to the gateway.
+        $this->post_process_submission( $invoice, $prepared, $shipping );
+    }
 
-	/**
-	 * Validates the submission.
-	 *
-	 */
-	protected function validate_submission() {
+    /**
+     * Validates the submission.
+     *
+     */
+    protected function validate_submission() {
 
-		$submission = $this->payment_form_submission;
-		$data       = $submission->get_data();
+        $submission = $this->payment_form_submission;
+        $data       = $submission->get_data();
 
-		// Do we have an error?
+        // Do we have an error?
         if ( ! empty( $submission->last_error ) ) {
-			wp_send_json_error( $submission->last_error );
+            wp_send_json_error( $submission->last_error );
         }
 
-		// We need a billing email.
+        // We need a billing email.
         if ( ! $submission->has_billing_email() ) {
             wp_send_json_error( __( 'Provide a valid billing email.', 'invoicing' ) );
-		}
+        }
 
-		// Non-recurring gateways should not be allowed to process recurring invoices.
-		if ( $submission->should_collect_payment_details() && $submission->has_recurring && ! wpinv_gateway_support_subscription( $data['wpi-gateway'] ) ) {
-			wp_send_json_error( __( 'The selected payment gateway does not support subscription payments.', 'invoicing' ) );
-		}
+        // Non-recurring gateways should not be allowed to process recurring invoices.
+        if ( $submission->should_collect_payment_details() && $submission->has_recurring && ! wpinv_gateway_support_subscription( $data['wpi-gateway'] ) ) {
+            wp_send_json_error( __( 'The selected payment gateway does not support subscription payments.', 'invoicing' ) );
+        }
 
-		// Ensure the gateway is active.
-		if ( $submission->should_collect_payment_details() && ! wpinv_is_gateway_active( $data['wpi-gateway'] ) ) {
-			wpinv_set_error( 'invalid_gateway', __( 'The selected payment gateway is not active', 'invoicing' ) );
-		}
+        // Ensure the gateway is active.
+        if ( $submission->should_collect_payment_details() && ! wpinv_is_gateway_active( $data['wpi-gateway'] ) ) {
+            wpinv_set_error( 'invalid_gateway', __( 'The selected payment gateway is not active', 'invoicing' ) );
+        }
 
-		// Clear any existing errors.
-		wpinv_clear_errors();
+        // Clear any existing errors.
+        wpinv_clear_errors();
 
-		// Allow themes and plugins to hook to errors
-		do_action( 'getpaid_checkout_error_checks', $submission );
+        // Allow themes and plugins to hook to errors
+        do_action( 'getpaid_checkout_error_checks', $submission );
 
-		// Do we have any errors?
+        // Do we have any errors?
         if ( wpinv_get_errors() ) {
             wp_send_json_error( getpaid_get_errors_html() );
-		}
+        }
 
-	}
+    }
 
-	/**
-	 * Retrieves submission items.
-	 *
-	 * @return GetPaid_Form_Item[]
-	 */
-	protected function get_submission_items() {
+    /**
+     * Retrieves submission items.
+     *
+     * @return GetPaid_Form_Item[]
+     */
+    protected function get_submission_items() {
 
-		$items = $this->payment_form_submission->get_items();
+        $items = $this->payment_form_submission->get_items();
 
         // Ensure that we have items.
         if ( empty( $items ) && ! $this->payment_form_submission->has_fees() ) {
             wp_send_json_error( __( 'Please provide at least one item or amount.', 'invoicing' ) );
-		}
-
-		return $items;
-	}
-
-	/**
-	 * Retrieves submission invoice.
-	 *
-	 * @return WPInv_Invoice
-	 */
-	protected function get_submission_invoice() {
-		$submission = $this->payment_form_submission;
-
-		if ( ! $submission->has_invoice() ) {
-			$invoice = new WPInv_Invoice();
-			$invoice->set_created_via( 'payment_form' );
-			return $invoice;
         }
 
-		$invoice = $submission->get_invoice();
+        return $items;
+    }
+
+    /**
+     * Retrieves submission invoice.
+     *
+     * @return WPInv_Invoice
+     */
+    protected function get_submission_invoice() {
+        $submission = $this->payment_form_submission;
+
+        if ( ! $submission->has_invoice() ) {
+            $invoice = new WPInv_Invoice();
+            $invoice->set_created_via( 'payment_form' );
+            return $invoice;
+        }
+
+        $invoice = $submission->get_invoice();
 
-		// Make sure that it is neither paid or refunded.
-		if ( $invoice->is_paid() || $invoice->is_refunded() ) {
-			wp_send_json_error( __( 'This invoice has already been paid for.', 'invoicing' ) );
-		}
+        // Make sure that it is neither paid or refunded.
+        if ( $invoice->is_paid() || $invoice->is_refunded() ) {
+            wp_send_json_error( __( 'This invoice has already been paid for.', 'invoicing' ) );
+        }
 
-		return $invoice;
-	}
+        return $invoice;
+    }
 
-	/**
-	 * Processes the submission invoice.
-	 *
-	 * @param WPInv_Invoice $invoice
-	 * @param GetPaid_Form_Item[] $items
-	 * @return WPInv_Invoice
-	 */
-	protected function process_submission_invoice( $invoice, $items ) {
+    /**
+     * Processes the submission invoice.
+     *
+     * @param WPInv_Invoice $invoice
+     * @param GetPaid_Form_Item[] $items
+     * @return WPInv_Invoice
+     */
+    protected function process_submission_invoice( $invoice, $items ) {
 
-		$submission = $this->payment_form_submission;
+        $submission = $this->payment_form_submission;
 
-		// Set-up the invoice details.
-		$invoice->set_email( sanitize_email( $submission->get_billing_email() ) );
-		$invoice->set_user_id( $this->get_submission_customer() );
-		$invoice->set_payment_form( absint( $submission->get_payment_form()->get_id() ) );
+        // Set-up the invoice details.
+        $invoice->set_email( sanitize_email( $submission->get_billing_email() ) );
+        $invoice->set_user_id( $this->get_submission_customer() );
+        $invoice->set_payment_form( absint( $submission->get_payment_form()->get_id() ) );
         $invoice->set_items( $items );
         $invoice->set_fees( $submission->get_fees() );
         $invoice->set_taxes( $submission->get_taxes() );
-		$invoice->set_discounts( $submission->get_discounts() );
-		$invoice->set_gateway( $submission->get_field( 'wpi-gateway' ) );
-		$invoice->set_currency( $submission->get_currency() );
+        $invoice->set_discounts( $submission->get_discounts() );
+        $invoice->set_gateway( $submission->get_field( 'wpi-gateway' ) );
+        $invoice->set_currency( $submission->get_currency() );
 
-		$address_confirmed = $submission->get_field( 'confirm-address' );
-		$invoice->set_address_confirmed( ! empty( $address_confirmed ) );
+        $address_confirmed = $submission->get_field( 'confirm-address' );
+        $invoice->set_address_confirmed( ! empty( $address_confirmed ) );
 
-		if ( $submission->has_discount_code() ) {
+        if ( $submission->has_discount_code() ) {
             $invoice->set_discount_code( $submission->get_discount_code() );
-		}
-
-		getpaid_maybe_add_default_address( $invoice );
-		return $invoice;
-	}
-
-	/**
-	 * Retrieves the submission's customer.
-	 *
-	 * @return int The customer id.
-	 */
-	protected function get_submission_customer() {
-		$submission = $this->payment_form_submission;
-
-		// If this is an existing invoice...
-		if ( $submission->has_invoice() ) {
-			return $submission->get_invoice()->get_user_id();
-		}
-
-		// (Maybe) create the user.
+        }
+
+        getpaid_maybe_add_default_address( $invoice );
+        return $invoice;
+    }
+
+    /**
+     * Retrieves the submission's customer.
+     *
+     * @return int The customer id.
+     */
+    protected function get_submission_customer() {
+        $submission = $this->payment_form_submission;
+
+        // If this is an existing invoice...
+        if ( $submission->has_invoice() ) {
+            return $submission->get_invoice()->get_user_id();
+        }
+
+        // (Maybe) create the user.
         $user = get_current_user_id();
 
         if ( empty( $user ) ) {
@@ -195,11 +195,11 @@ 
         if ( empty( $user ) ) {
             $user = wpinv_create_user( $submission->get_billing_email() );
 
-			// (Maybe) send new user notification.
-			$should_send_notification = wpinv_get_option( 'disable_new_user_emails' );
-			if ( ! empty( $user ) && is_numeric( $user ) && apply_filters( 'getpaid_send_new_user_notification', empty( $should_send_notification ), $user ) ) {
-				wp_send_new_user_notifications( $user, 'user' );
-			}
+            // (Maybe) send new user notification.
+            $should_send_notification = wpinv_get_option( 'disable_new_user_emails' );
+            if ( ! empty( $user ) && is_numeric( $user ) && apply_filters( 'getpaid_send_new_user_notification', empty( $should_send_notification ), $user ) ) {
+                wp_send_new_user_notifications( $user, 'user' );
+            }
 
         }
 
@@ -209,49 +209,49 @@ 
 
         if ( is_numeric( $user ) ) {
             return $user;
-		}
+        }
 
-		return $user->ID;
+        return $user->ID;
 
-	}
+    }
 
-	/**
+    /**
      * Prepares submission data for saving to the database.
      *
-	 * @return array
+     * @return array
      */
     public function prepare_submission_data_for_saving() {
 
-		$submission = $this->payment_form_submission;
+        $submission = $this->payment_form_submission;
 
-		// Prepared submission details.
+        // Prepared submission details.
         $prepared = array(
-			'all'  => array(),
-			'meta' => array(),
-		);
+            'all'  => array(),
+            'meta' => array(),
+        );
 
         // Raw submission details.
-		$data     = $submission->get_data();
+        $data     = $submission->get_data();
 
-		// Loop through the submitted details.
+        // Loop through the submitted details.
         foreach ( $submission->get_payment_form()->get_elements() as $field ) {
 
-			// Skip premade fields.
+            // Skip premade fields.
             if ( ! empty( $field['premade'] ) ) {
                 continue;
             }
 
-			// Ensure address is provided.
-			if ( $field['type'] == 'address' ) {
+            // Ensure address is provided.
+            if ( $field['type'] == 'address' ) {
                 $address_type = isset( $field['address_type'] ) && 'shipping' === $field['address_type'] ? 'shipping' : 'billing';
 
-				foreach ( $field['fields'] as $address_field ) {
+                foreach ( $field['fields'] as $address_field ) {
 
-					if ( ! empty( $address_field['visible'] ) && ! empty( $address_field['required'] ) && '' === trim( $_POST[ $address_type ][ $address_field['name'] ] ) ) {
-						wp_send_json_error( __( 'Please fill all required fields.', 'invoicing' ) );
-					}
+                    if ( ! empty( $address_field['visible'] ) && ! empty( $address_field['required'] ) && '' === trim( $_POST[ $address_type ][ $address_field['name'] ] ) ) {
+                        wp_send_json_error( __( 'Please fill all required fields.', 'invoicing' ) );
+                    }
 
-				}
+                }
 
             }
 
@@ -263,31 +263,31 @@ 
             // Handle misc fields.
             if ( isset( $data[ $field['id'] ] ) ) {
 
-				// Uploads.
-				if ( $field['type'] == 'file_upload' ) {
-					$max_file_num = empty( $field['max_file_num'] ) ? 1 : absint( $field['max_file_num'] );
+                // Uploads.
+                if ( $field['type'] == 'file_upload' ) {
+                    $max_file_num = empty( $field['max_file_num'] ) ? 1 : absint( $field['max_file_num'] );
 
-					if ( count( $data[ $field['id'] ] ) > $max_file_num ) {
-						wp_send_json_error( __( 'Maximum number of allowed files exceeded.', 'invoicing' ) );
-					}
+                    if ( count( $data[ $field['id'] ] ) > $max_file_num ) {
+                        wp_send_json_error( __( 'Maximum number of allowed files exceeded.', 'invoicing' ) );
+                    }
 
-					$value = array();
+                    $value = array();
 
-					foreach ( $data[ $field['id'] ] as $url => $name ) {
-						$value[] = sprintf(
-							'<a href="%s" target="_blank">%s</a>',
-							esc_url_raw( $url ),
-							esc_html( $name )
-						);
-					}
+                    foreach ( $data[ $field['id'] ] as $url => $name ) {
+                        $value[] = sprintf(
+                            '<a href="%s" target="_blank">%s</a>',
+                            esc_url_raw( $url ),
+                            esc_html( $name )
+                        );
+                    }
 
-					$value = implode( ' | ', $value );
+                    $value = implode( ' | ', $value );
 
-				} else if ( $field['type'] == 'checkbox' ) {
-					$value = isset( $data[ $field['id'] ] ) ? __( 'Yes', 'invoicing' ) : __( 'No', 'invoicing' );
-				} else {
-					$value = wp_kses_post( $data[ $field['id'] ] );
-				}
+                } else if ( $field['type'] == 'checkbox' ) {
+                    $value = isset( $data[ $field['id'] ] ) ? __( 'Yes', 'invoicing' ) : __( 'No', 'invoicing' );
+                } else {
+                    $value = wp_kses_post( $data[ $field['id'] ] );
+                }
 
                 $label = $field['id'];
 
@@ -295,189 +295,189 @@ 
                     $label = $field['label'];
                 }
 
-				if ( ! empty( $field['add_meta'] ) ) {
-					$prepared['meta'][ wpinv_clean( $label ) ] = wp_kses_post_deep( $value );
-				}
-				$prepared['all'][ wpinv_clean( $label ) ] = wp_kses_post_deep( $value );
+                if ( ! empty( $field['add_meta'] ) ) {
+                    $prepared['meta'][ wpinv_clean( $label ) ] = wp_kses_post_deep( $value );
+                }
+                $prepared['all'][ wpinv_clean( $label ) ] = wp_kses_post_deep( $value );
 
             }
 
-		}
+        }
 
-		return $prepared;
+        return $prepared;
 
-	}
+    }
 
-	/**
+    /**
      * Retrieves address details.
      *
-	 * @return array
-	 * @param WPInv_Invoice $invoice
-	 * @param string $type
+     * @return array
+     * @param WPInv_Invoice $invoice
+     * @param string $type
      */
     public function prepare_address_details( $invoice, $type = 'billing' ) {
 
-		$data     = $this->payment_form_submission->get_data();
-		$type     = sanitize_key( $type );
-		$address  = array();
-		$prepared = array();
+        $data     = $this->payment_form_submission->get_data();
+        $type     = sanitize_key( $type );
+        $address  = array();
+        $prepared = array();
 
-		if ( ! empty( $data[ $type ] ) ) {
-			$address = $data[ $type ];
-		}
+        if ( ! empty( $data[ $type ] ) ) {
+            $address = $data[ $type ];
+        }
 
-		// Clean address details.
-		foreach ( $address as $key => $value ) {
-			$key             = sanitize_key( $key );
-			$key             = str_replace( 'wpinv_', '', $key );
-			$value           = wpinv_clean( $value );
-			$prepared[ $key] = apply_filters( "getpaid_checkout_{$type}_address_$key", $value, $this->payment_form_submission, $invoice );
-		}
+        // Clean address details.
+        foreach ( $address as $key => $value ) {
+            $key             = sanitize_key( $key );
+            $key             = str_replace( 'wpinv_', '', $key );
+            $value           = wpinv_clean( $value );
+            $prepared[ $key] = apply_filters( "getpaid_checkout_{$type}_address_$key", $value, $this->payment_form_submission, $invoice );
+        }
 
-		// Filter address details.
-		$prepared = apply_filters( "getpaid_checkout_{$type}_address", $prepared, $this->payment_form_submission, $invoice );
+        // Filter address details.
+        $prepared = apply_filters( "getpaid_checkout_{$type}_address", $prepared, $this->payment_form_submission, $invoice );
 
-		// Remove non-whitelisted values.
-		return array_filter( $prepared, 'getpaid_is_address_field_whitelisted', ARRAY_FILTER_USE_KEY );
+        // Remove non-whitelisted values.
+        return array_filter( $prepared, 'getpaid_is_address_field_whitelisted', ARRAY_FILTER_USE_KEY );
 
-	}
+    }
 
-	/**
+    /**
      * Prepares the billing details.
      *
-	 * @return array
-	 * @param WPInv_Invoice $invoice
+     * @return array
+     * @param WPInv_Invoice $invoice
      */
     protected function prepare_billing_info( &$invoice ) {
 
-		$billing_address = $this->prepare_address_details( $invoice, 'billing' );
+        $billing_address = $this->prepare_address_details( $invoice, 'billing' );
 
-		// Update the invoice with the billing details.
-		$invoice->set_props( $billing_address );
+        // Update the invoice with the billing details.
+        $invoice->set_props( $billing_address );
 
-	}
+    }
 
-	/**
+    /**
      * Prepares the shipping details.
      *
-	 * @return array
-	 * @param WPInv_Invoice $invoice
+     * @return array
+     * @param WPInv_Invoice $invoice
      */
     protected function prepare_shipping_info( $invoice ) {
 
-		$data = $this->payment_form_submission->get_data();
+        $data = $this->payment_form_submission->get_data();
 
-		if ( empty( $data['same-shipping-address'] ) ) {
-			return $this->prepare_address_details( $invoice, 'shipping' );
-		}
+        if ( empty( $data['same-shipping-address'] ) ) {
+            return $this->prepare_address_details( $invoice, 'shipping' );
+        }
 
-		return $this->prepare_address_details( $invoice, 'billing' );
+        return $this->prepare_address_details( $invoice, 'billing' );
 
-	}
+    }
 
-	/**
-	 * Confirms the submission is valid and send users to the gateway.
-	 *
-	 * @param WPInv_Invoice $invoice
-	 * @param array $prepared_payment_form_data
-	 * @param array $shipping
-	 */
-	protected function post_process_submission( $invoice, $prepared_payment_form_data, $shipping ) {
+    /**
+     * Confirms the submission is valid and send users to the gateway.
+     *
+     * @param WPInv_Invoice $invoice
+     * @param array $prepared_payment_form_data
+     * @param array $shipping
+     */
+    protected function post_process_submission( $invoice, $prepared_payment_form_data, $shipping ) {
 
-		// Ensure the invoice exists.
+        // Ensure the invoice exists.
         if ( ! $invoice->exists() ) {
             wp_send_json_error( __( 'An error occured while saving your invoice. Please try again.', 'invoicing' ) );
         }
 
-		// Save payment form data.
-		$prepared_payment_form_data = apply_filters( 'getpaid_prepared_payment_form_data', $prepared_payment_form_data, $invoice );
+        // Save payment form data.
+        $prepared_payment_form_data = apply_filters( 'getpaid_prepared_payment_form_data', $prepared_payment_form_data, $invoice );
         delete_post_meta( $invoice->get_id(), 'payment_form_data' );
-		delete_post_meta( $invoice->get_id(), 'additional_meta_data' );
-		if ( ! empty( $prepared_payment_form_data ) ) {
+        delete_post_meta( $invoice->get_id(), 'additional_meta_data' );
+        if ( ! empty( $prepared_payment_form_data ) ) {
 
-			if ( ! empty( $prepared_payment_form_data['all'] ) ) {
-				update_post_meta( $invoice->get_id(), 'payment_form_data', $prepared_payment_form_data['all'] );
-			}
+            if ( ! empty( $prepared_payment_form_data['all'] ) ) {
+                update_post_meta( $invoice->get_id(), 'payment_form_data', $prepared_payment_form_data['all'] );
+            }
 
-			if ( ! empty( $prepared_payment_form_data['meta'] ) ) {
-				update_post_meta( $invoice->get_id(), 'additional_meta_data', $prepared_payment_form_data['meta'] );
-			}
+            if ( ! empty( $prepared_payment_form_data['meta'] ) ) {
+                update_post_meta( $invoice->get_id(), 'additional_meta_data', $prepared_payment_form_data['meta'] );
+            }
 
-		}
+        }
 
-		// Save payment form data.
+        // Save payment form data.
         if ( ! empty( $shipping ) ) {
             update_post_meta( $invoice->get_id(), 'shipping_address', $shipping );
-		}
+        }
 
-		// Backwards compatibility.
+        // Backwards compatibility.
         add_filter( 'wp_redirect', array( $this, 'send_redirect_response' ) );
 
-		$this->process_payment( $invoice );
+        $this->process_payment( $invoice );
 
         // If we are here, there was an error.
-		wpinv_send_back_to_checkout( $invoice );
+        wpinv_send_back_to_checkout( $invoice );
 
-	}
+    }
 
-	/**
-	 * Processes the actual payment.
-	 *
-	 * @param WPInv_Invoice $invoice
-	 */
-	protected function process_payment( $invoice ) {
+    /**
+     * Processes the actual payment.
+     *
+     * @param WPInv_Invoice $invoice
+     */
+    protected function process_payment( $invoice ) {
 
-		// Clear any checkout errors.
-		wpinv_clear_errors();
+        // Clear any checkout errors.
+        wpinv_clear_errors();
 
-		// No need to send free invoices to the gateway.
-		if ( $invoice->is_free() ) {
-			$this->process_free_payment( $invoice );
-		}
+        // No need to send free invoices to the gateway.
+        if ( $invoice->is_free() ) {
+            $this->process_free_payment( $invoice );
+        }
 
-		$submission = $this->payment_form_submission;
+        $submission = $this->payment_form_submission;
 
-		// Fires before sending to the gateway.
-		do_action( 'getpaid_checkout_before_gateway', $invoice, $submission );
+        // Fires before sending to the gateway.
+        do_action( 'getpaid_checkout_before_gateway', $invoice, $submission );
 
-		// Allow the sumission data to be modified before it is sent to the gateway.
-		$submission_data    = $submission->get_data();
-		$submission_gateway = apply_filters( 'getpaid_gateway_submission_gateway', $invoice->get_gateway(), $submission, $invoice );
-		$submission_data    = apply_filters( 'getpaid_gateway_submission_data', $submission_data, $submission, $invoice );
+        // Allow the sumission data to be modified before it is sent to the gateway.
+        $submission_data    = $submission->get_data();
+        $submission_gateway = apply_filters( 'getpaid_gateway_submission_gateway', $invoice->get_gateway(), $submission, $invoice );
+        $submission_data    = apply_filters( 'getpaid_gateway_submission_data', $submission_data, $submission, $invoice );
 
-		// Validate the currency.
-		if ( ! apply_filters( "getpaid_gateway_{$submission_gateway}_is_valid_for_currency", true, $invoice->get_currency() ) ) {
-			wpinv_set_error( 'invalid_currency', __( 'The chosen payment gateway does not support this currency', 'invoicing' ) );
-		}
+        // Validate the currency.
+        if ( ! apply_filters( "getpaid_gateway_{$submission_gateway}_is_valid_for_currency", true, $invoice->get_currency() ) ) {
+            wpinv_set_error( 'invalid_currency', __( 'The chosen payment gateway does not support this currency', 'invoicing' ) );
+        }
 
-		// Check to see if we have any errors.
-		if ( wpinv_get_errors() ) {
-			wpinv_send_back_to_checkout( $invoice );
-		}
+        // Check to see if we have any errors.
+        if ( wpinv_get_errors() ) {
+            wpinv_send_back_to_checkout( $invoice );
+        }
 
-		// Send info to the gateway for payment processing
-		do_action( "getpaid_gateway_$submission_gateway", $invoice, $submission_data, $submission );
+        // Send info to the gateway for payment processing
+        do_action( "getpaid_gateway_$submission_gateway", $invoice, $submission_data, $submission );
 
-		// Backwards compatibility.
-		wpinv_send_to_gateway( $submission_gateway, $invoice );
+        // Backwards compatibility.
+        wpinv_send_to_gateway( $submission_gateway, $invoice );
 
-	}
+    }
 
-	/**
-	 * Marks the invoice as paid in case the checkout is free.
-	 *
-	 * @param WPInv_Invoice $invoice
-	 */
-	protected function process_free_payment( $invoice ) {
+    /**
+     * Marks the invoice as paid in case the checkout is free.
+     *
+     * @param WPInv_Invoice $invoice
+     */
+    protected function process_free_payment( $invoice ) {
 
-		$invoice->set_gateway( 'none' );
-		$invoice->add_note( __( "This is a free invoice and won't be sent to the payment gateway", 'invoicing' ), false, false, true );
-		$invoice->mark_paid();
-		wpinv_send_to_success_page( array( 'invoice_key' => $invoice->get_key() ) );
+        $invoice->set_gateway( 'none' );
+        $invoice->add_note( __( "This is a free invoice and won't be sent to the payment gateway", 'invoicing' ), false, false, true );
+        $invoice->mark_paid();
+        wpinv_send_to_success_page( array( 'invoice_key' => $invoice->get_key() ) );
 
-	}
+    }
 
-	/**
+    /**
      * Sends a redrect response to payment details.
      *
      */