wpmudev_smushcdn_bg_fix

<?php
/**
* Plugin Name: [Smush Pro] - data background support
* Plugin URI: https://premium.wpmudev.org/
* Description:
* Author: Alessandro Kaounas @ WPMUDEV
* Author URI: https://premium.wpmudev.org/
* License: GPLv2 or later
*/

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

use Smush\WP_Smush;
use Smush\Core\Settings;
use Smush\Core\Modules\Helpers\Parser;

if ( ! class_exists( 'WPMUDEV_Smush_Smart_Slider' ) ) {

    class WPMUDEV_Smush_Smart_Slider {

        private static $_instance       = null;

        private $cdn                    = false;
        private $lazy_load              = false;

        public static function get_instance() {

            if( is_null( self::$_instance ) ){
                self::$_instance = new WPMUDEV_Smush_Smart_Slider();
            }
            return self::$_instance;

        }

        private function __construct() {

            $this->init();

        }

        private function init() {

            $settings = Settings::get_instance();

            if ( $settings->get( 'lazy_load' ) ) {
                $this->lazy_load = $settings->get( 'lazy_load' );
            }

            if ( $settings->get( 'cdn' ) ) {
                $this->cdn = $settings->get( 'cdn' );
            }

            // Do not parse page if CDN and Lazy load modules are disabled.
            if ( ! $this->cdn && ! $this->lazy_load ) {
                return $content;
            }

            add_action( 'template_redirect', function () { ob_start( array( $this, 'parse_page' ) ); }, 1 );

        }

        public function parse_page( $content ) {

            if ( empty( $content ) || apply_filters( 'wp_smush_should_skip_parse', false ) ) {
                return $content;
            }

            $content = $this->process_custom_images( $content );

            return $content;

        }

        private function process_custom_images( $content ) {

            // Match elements with $this->data_attr attribute
            if ( preg_match_all( '/(?:data-(?:desktop|ae-bg|desktop-retina|tablet|tablet-retina|mobile|mobile-retina)=[\'|"](?P<img_url>(http?s?:?|)\/\/[^"\']*\.(?:png|jpg|jpeg|gif))[\'|"]\)?){1}/is', $content, $images ) ) {
                foreach ( $images as $key => $unused ) {
                    // Simplify the output as much as possible, mostly for confirming test results.
                    if ( is_numeric( $key ) && $key > 0 ) {
                        unset( $images[ $key ] );
                    }
                }
            }

            if ( empty( $images ) ) {
                return $content;
            }

            foreach ( $images['img_url'] as $key => $image ) {

                $content = str_replace( $image, WP_Smush::get_instance()->core()->mod->cdn->generate_cdn_url( $image ), $content );

            }

            return $content;

        }

    }

    if ( ! function_exists( 'wpmudev_smush_smart_slider' ) ) {

        function wpmudev_smush_smart_slider() {
            return WPMUDEV_Smush_Smart_Slider::get_instance();
        };

        add_action( 'plugins_loaded', 'wpmudev_smush_smart_slider', 99 );
    }

}