AutoLoadNextPost / auto-load-next-post

auto-load-next-post.php

<?php
/**
 * Plugin Name: Auto Load Next Post
 * Plugin URI:  https://autoloadnextpost.com
 * Description: Increase your pageviews on your site as readers continue reading your posts scrolling down the page.
 * Author:      Sébastien Dumont
 * Author URI:  https://sebastiendumont.com
 * Version:     1.4.12
 * Text Domain: auto-load-next-post
 * Domain Path: /languages/
 *
 * Copyright: © 2018 Sébastien Dumont, (mailme@sebastiendumont.com)
 *
 * License: GNU General Public License v3.0
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 *
 * @package   Auto Load Next Post
 * @author    Sébastien Dumont
 * @copyright Copyright © 2018, Sébastien Dumont
 * @license   GNU General Public License v3.0 http://www.gnu.org/licenses/gpl-3.0.html
 */

/**
 * Main Auto Load Next Post Class
 *
 * The main instance of the plugin.
 *
 * @version 1.4.10
 */
if ( ! class_exists('Auto_Load_Next_Post') ) {

	class Auto_Load_Next_Post {

		/**
		 * @var Auto_Load_Next_Post - The single instance of the class
		 *
		 * @access protected
		 * @static
		 * @since  1.0.0
		 */
		protected static $_instance = null;

		/**
		 * Main Auto Load Next Post Instance
		 *
		 * Ensures only one instance of Auto Load Next Post is loaded or can be loaded.
		 *
		 * @access public
		 * @since  1.0.0
		 * @static
		 * @see    Auto_Load_Next_Post()
		 * @return Auto_Load_Next_Post Single instance.
		 */
		public static function instance() {
			if ( is_null( self::$_instance ) ) {
				self::$_instance = new self();
				self::$_instance->setup_constants();
				self::$_instance->includes();
			}
			return self::$_instance;
		} // END instance()

		/**
		 * Cloning is forbidden.
		 *
		 * @access public
		 * @since  1.0.0
		 * @return void
		 */
		public function __clone() {
			// Cloning instances of the class is forbidden
			_doing_it_wrong( __FUNCTION__, __( 'Cloning this object is forbidden.', 'auto-load-next-post' ), AUTO_LOAD_NEXT_POST_VERSION );
		} // END __clone()

		/**
		 * Unserializing instances of this class is forbidden.
		 *
		 * @access public
		 * @since  1.0.0
		 * @return void
		 */
		public function __wakeup() {
			_doing_it_wrong( __FUNCTION__, __( 'Unserializing instances of this class is forbidden.', 'auto-load-next-post' ), AUTO_LOAD_NEXT_POST_VERSION );
		} // END __wakeup()

		/**
		 * Auto_Load_Next_Post Constructor
		 *
		 * @access public
		 * @since  1.0.0
		 * @return Auto_Load_Next_Post

Adding a @return annotation to constructors is generally not recommended as a constructor does not have a meaningful return value.

		 */
		public function __construct() {
			// Auto-load classes on demand
			if ( function_exists("__autoload") ) {
				spl_autoload_register("__autoload");
			}

			spl_autoload_register( array( $this, 'autoload' ) );

			// Load translation files.
			add_action( 'init', array( $this, 'load_plugin_textdomain' ) );

			// Load Auto Load Next Post scripts on the frontend.
			add_action( 'wp_enqueue_scripts', array( $this, 'alnp_scripts' ) );
		} // END __construct()

		/**
		 * Auto-load Auto Load Next Post classes on demand to reduce memory consumption.
		 *
		 * @since  1.0.0
		 * @access public
		 * @param  mixed $class
		 * @return void
		 */
		public function autoload( $class ) {
			$path  = null;
			$file  = strtolower( 'class-' . str_replace( '_', '-', $class ) ) . '.php';

			if ( strpos( $class, 'auto_load_next_post_admin' ) === 0 ) {
				$path = AUTO_LOAD_NEXT_POST_FILE_PATH . '/includes/admin/';
			} else if ( strpos( $class, 'auto_load_next_post_' ) === 0 ) {
				$path = AUTO_LOAD_NEXT_POST_FILE_PATH . '/includes/';
			}

			if ( $path !== null && is_readable( $path . $file ) ) {
				include_once( $path . $file );
				return true;
			}
		} // END autoload()

		/**
		 * Setup Constants
		 *
		 * @since   1.4.3
		 * @version 1.4.10
		 * @access private
		 */
		private function setup_constants() {
			$this->define('AUTO_LOAD_NEXT_POST_VERSION', '1.4.10');
			$this->define('AUTO_LOAD_NEXT_POST_FILE', __FILE__);
			$this->define('AUTO_LOAD_NEXT_POST_SLUG', 'auto-load-next-post');

			$this->define('AUTO_LOAD_NEXT_POST_URL_PATH', untrailingslashit(plugins_url('/', __FILE__)));
			$this->define('AUTO_LOAD_NEXT_POST_FILE_PATH', untrailingslashit(plugin_dir_path(__FILE__)));
			$this->define('AUTO_LOAD_NEXT_POST_TEMPLATE_PATH', 'auto-load-next-post/');

			$this->define('AUTO_LOAD_NEXT_POST_WP_VERSION_REQUIRE', '4.3');

			$suffix       = defined('SCRIPT_DEBUG') && SCRIPT_DEBUG ? '' : '.min';
			$debug_suffix = defined('ALNP_DEV_DEBUG') && ALNP_DEV_DEBUG ? '.dev' : '';

			$this->define('AUTO_LOAD_NEXT_POST_SCRIPT_MODE', $suffix);
			$this->define('AUTO_LOAD_NEXT_POST_DEBUG_MODE', $debug_suffix);
		} // END setup_constants()

		/**
		 * Define constant if not already set.
		 *
		 * @param  string $name
		 * @param  string|bool $value
		 * @access private
		 * @since  1.4.3
		 */
		private function define( $name, $value ) {
			if ( ! defined( $name ) ) {
				define( $name, $value );
			}
		} // END define()

		/*-----------------------------------------------------------------------------------*/
		/*  Load Files                                                                       */
		/*-----------------------------------------------------------------------------------*/

		/**
		 * Include required core files used in admin and on the frontend.
		 *
		 * @access  public
		 * @since   1.0.0
		 * @version 1.4.10
		 * @return  void
		 */
		public function includes() {
			include_once( dirname( __FILE__ ) . '/includes/auto-load-next-post-core-functions.php'); // Contains core functions for the front/back end.

			// Include admin class to handle all back-end functions.
			if ( is_admin() ) {
				include_once( dirname( __FILE__ ) . '/includes/admin/class-auto-load-next-post-admin.php'); // Admin section.
			}

			// Install.
			require_once( dirname( __FILE__ ) . '/includes/class-auto-load-next-post-install.php' );

			/**
			 * Auto Load Next Post is fully loaded.
			 */
			do_action( 'auto_load_next_post_loaded' );
		} // END includes()

		/**
		 * Make the plugin translation ready.
		 *
		 * Translations should be added in the WordPress language directory:
		 *      - WP_LANG_DIR/plugins/auto-load-next-post-LOCALE.mo
		 *
		 * @access  public
		 * @since   1.0.0
		 * @version 1.4.10
		 * @return  void
		 */
		public function load_plugin_textdomain() {
			load_plugin_textdomain( 'auto-load-next-post', false, dirname( plugin_basename( __FILE__ ) ) . '/languages/' );
		} // END load_plugin_textdomain()

		/**
		 * Registers and enqueues stylesheets and javascripts for the front of the site.
		 *
		 * @access  public
		 * @since   1.3.2
		 * @version 1.4.12
		 */
		public function alnp_scripts() {
			/**
			 * Load the Javascript if found as a singluar post.
			 */
			if ( is_singular() && get_post_type() == 'post' ) {
				$this->load_file( 'auto-load-next-post-scrollspy', '/assets/js/libs/scrollspy' . AUTO_LOAD_NEXT_POST_SCRIPT_MODE . '.js', true, array('jquery'), AUTO_LOAD_NEXT_POST_VERSION );

				// Only load History.js when not in the customizer.
				if ( ! is_customize_preview() ) {
					$this->load_file( 'auto-load-next-post-history', '/assets/js/libs/jquery.history.js', true, array('jquery'), AUTO_LOAD_NEXT_POST_VERSION );
				}

				$this->load_file( 'auto-load-next-post-script', '/assets/js/frontend/auto-load-next-post' . AUTO_LOAD_NEXT_POST_DEBUG_MODE.AUTO_LOAD_NEXT_POST_SCRIPT_MODE . '.js', true, array('auto-load-next-post-scrollspy'), AUTO_LOAD_NEXT_POST_VERSION );

				// Variables for JS scripts
				wp_localize_script( 'auto-load-next-post-script', 'auto_load_next_post_params', array(
					'alnp_version'              => AUTO_LOAD_NEXT_POST_VERSION,
					'alnp_content_container'    => get_option('auto_load_next_post_content_container'),
					'alnp_title_selector'       => get_option('auto_load_next_post_title_selector'),
					'alnp_navigation_container' => get_option('auto_load_next_post_navigation_container'),
					'alnp_comments_container'   => get_option('auto_load_next_post_comments_container'),
					'alnp_remove_comments'      => get_option('auto_load_next_post_remove_comments'),
					'alnp_google_analytics'     => get_option('auto_load_next_post_google_analytics'),
					'alnp_event_on_load'        => get_option('auto_load_next_post_on_load_event'),
					'alnp_event_on_entering'    => get_option('auto_load_next_post_on_entering_event'),
					'alnp_is_customizer'        => is_customize_preview()
				) );
			} // END if is_singular() && get_post_type()
		} // END alnp_scripts()

		/**
		 * Helper function for registering and enqueueing scripts and styles.
		 *
		 * @access public
		 * @since  1.0.0
		 * @static
		 * @param  string  $name      The ID to register with WordPress.
		 * @param  string  $file_path The path to the actual file.
		 * @param  bool    $is_script Optional, argument for if the incoming file_path is a JavaScript source file.
		 * @param  array   $support   Optional, for requiring other javascripts for the source file you are calling.
		 * @param  string  $version   Optional, can match the version of the plugin or version of the source file.
		 * @global string  $wp_version
		 */
		public static function load_file( $name, $file_path, $is_script = false, $support = array(), $version = '' ) {
			global $wp_version;

			$url = AUTO_LOAD_NEXT_POST_URL_PATH . $file_path; // URL to the file.

			if ( file_exists( AUTO_LOAD_NEXT_POST_FILE_PATH . $file_path ) ) {
				if ( $is_script ) {
					wp_register_script( $name, $url, $support, $version );
					wp_enqueue_script( $name );
				} else {
					wp_register_style( $name, $url );
					wp_enqueue_style( $name );
				} // end if
			} // end if

		} // END load_file()

	} // END Auto_Load_Next_Post()

} // END class exists 'Auto_Load_Next_Post'

/**
 * This runs the plugin if the required PHP version has been met.
 */
function run_auto_load_next_post() {
	return Auto_Load_Next_Post::instance();
} // END run_auto_load_next_post()

// Fetch the Php version checker.
if ( ! class_exists( 'WP_Update_Php' ) ) {
	require_once( dirname( __FILE__ ) . '/wp-update-php/wp-update-php.php' );
}
$updatePhp = new WP_Update_Php(
	array(
		'name' => 'Auto Load Next Post',
		'textdomain' => 'auto-load-next-post'
	),
	array(
		'minimum_version' => '5.6.0',
		'recommended_version' => '7.2'
	)
);

// If the miniumum version of PHP required is available then run the plugin.
if ( $updatePhp->does_it_meet_required_php_version() ) {
	add_action('plugins_loaded', 'run_auto_load_next_post', 20);
}