elementemplater-class.php

<?php

class ElemenTemplater {

        /**
         * A reference to an instance of this class.
         */
        private static $instance;

        /**
         * The array of templates that this plugin tracks.
         */
        protected $templates;

        /**
         * Returns an instance of this class. 
         */
        public static function get_instance() {

                if( null == self::$instance ) {
                    self::$instance = new ElemenTemplater();
                } 

                return self::$instance;

        }

        public function elementemplater_load_plugin_textdomain() {
		    load_plugin_textdomain( 'elementemplater' );
	    }
		
        /**
         * Initializes the plugin by setting filters and administration functions.
         */
        private function __construct() {

                $this->templates = array();
				
				add_action( 'init', array( $this, 'elementemplater_load_plugin_textdomain' ) );
				
				add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_styles' ), 998 );
				add_action( 'wp_enqueue_scripts', array( $this, 'elementemplater_styles' ), 999 );
				add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_scripts' ), 9999 );

                // Add a filter to the attributes metabox to inject template into the cache.
				if ( version_compare( floatval($GLOBALS['wp_version']), '4.7', '<' ) ) { // 4.6.1 and older
            		add_filter(
                		'page_attributes_dropdown_pages_args',
                		array( $this, 'register_project_templates' )
            		);
				} else { // Add a filter to the wp 4.7 version attributes metabox
            		add_filter(
                		'theme_page_templates', array( $this, 'add_new_template' )
            		);
				}

                // Add a filter to the save post to inject out template into the page cache
                add_filter(
					'wp_insert_post_data', 
					array( $this, 'register_project_templates' ) 
				);


                // Add a filter to the template include to determine if the page has our 
				// template assigned and return it's path
                add_filter(
					'template_include', 
					array( $this, 'view_project_template') 
				);

                // Add your templates to this array.
				$this->templates = array(
                    'templates/builder-fullwidth.php'     => __( 'Elementor Fullwidth Blank', 'elementemplater' ),
					'templates/builder-fullwidth-std.php' => __( 'Elementor Fullwidth Standard', 'elementemplater' ),
                );				
        }
		
		/**
     	 * Adds our template to the page dropdown for v4.7+
     	 *
     	 */
    	public function add_new_template( $posts_templates ) {
        	$posts_templates = array_merge( $posts_templates, $this->templates );
        	return $posts_templates;
    	}

        /**
         * Adds our template to the pages cache in order to trick WordPress
         * into thinking the template file exists where it doens't really exist.
         *
         */

        public function register_project_templates( $atts ) {

                // Create the key used for the themes cache
                $cache_key = 'page_templates-' . md5( get_theme_root() . '/' . get_stylesheet() );

                // Retrieve the cache list. 
				// If it doesn't exist, or it's empty prepare an array
				$templates = wp_get_theme()->get_page_templates();
                if ( empty( $templates ) ) {
                        $templates = array();
                } 

                // New cache, therefore remove the old one
                wp_cache_delete( $cache_key , 'themes');

                // Now add our template to the list of templates by merging our templates
                // with the existing templates array from the cache.
                $templates = array_merge( $templates, $this->templates );

                // Add the modified cache to allow WordPress to pick it up for listing
                // available templates
                wp_cache_add( $cache_key, $templates, 'themes', 1800 );

                return $atts;

        } 

        /**
         * Checks if the template is assigned to the page
         */
        public function view_project_template( $template ) {

                global $post;

                if (!isset($this->templates[get_post_meta( 
					$post->ID, '_wp_page_template', true 
				)] ) ) {
					
                    return $template;
						
                } 

                $file = plugin_dir_path(__FILE__). get_post_meta( 
					$post->ID, '_wp_page_template', true 
				);
				
                // Just to be safe, we check if the file exist first
                if( file_exists( $file ) ) {
                    return $file;
                } 
				else { echo $file; }

                return $template;

        }
		
		/**
	     * Enqueue Custom CSS - theme agnostic.
	     * @since   1.0.1
	     * @return  void
	     */
	    public function enqueue_styles() {
			if ( is_page_template( 'templates/builder-fullwidth.php' ) ) {
				wp_register_style( 'builder-fullwidth-style', plugins_url( 'assets/custom.css', __FILE__ ) );
			    wp_enqueue_style( 'builder-fullwidth-style' );
			}
		}
		
		 public function enqueue_scripts() {
			if ( is_page_template( 'templates/builder-fullwidth.php' ) ) {
				wp_enqueue_script( 'builder-fullwidth-js', plugins_url( 'assets/custom.js', __FILE__ ), array( 'jquery' ), '', true );
			}
		}
		
		/**
	     * Enqueue CSS for active theme.
	     * @since   1.0.0
	     * @return  void
	     */
	    public function elementemplater_styles() {
		    $theme = get_option( 'template' );
            $filename = plugin_dir_path( __FILE__ ) . 'inc/themes/' . $theme . '.php';
            if (file_exists($filename)) {
                include_once( $filename );
            }
	    }
} 

add_action( 'plugins_loaded', array( 'ElemenTemplater', 'get_instance' ) );