[Smush] - Bakery Carousel Excludes. Alter Smush's buffer for pages with Bakery Carousel

wpmudev_smush_bakery_carousel.php

<?php
/**
* Plugin Name: [Smush] - Bakery Carousel Excludes
* Plugin URI: https://premium.wpmudev.org/
* Description: Alter Smush's buffer for pages with Bakery Carousel
* Author: Panos Lyrakis @ WPMUDEV
* Author URI: https://premium.wpmudev.org/
* License: GPLv2 or later
*/

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

if ( ! class_exists( 'WPMUDEV_Smush_Bakery_Carousel_Excludes' ) ) {
    
    class WPMUDEV_Smush_Bakery_Carousel_Excludes {

        private static $_instance 		= null;

        private $lazy_load 				= false;
        private $cdn 					= false;
        private $background_images  	= false;
        protected $settings 			= null;
        protected $options 			= null;

        public static function get_instance() {

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

        private function __construct() {

        	$this->init();
        	add_action( 'template_redirect', array( $this, 'attempt_alter_buffer' ) );        	
        }

        private function init() {

        	$this->settings = WP_Smush_Settings::get_instance();
			$background_images = $this->settings->get( 'background_images' );

			if ( $background_images ) {
				$this->background_images = true;
			}

			//$this->parser->enable( 'cdn' );
			//$this->cdn = true;
			$this->lazy_load = true;
		}

        public function attempt_alter_buffer() {
        	ob_start( array( $this, 'maybe_alter_buffer' ) );
        }

        public function maybe_alter_buffer( $content, $flags ) {

        	$content = ob_get_contents();

			if ( strpos( $content, 'wpb_images_carousel' ) === false ) {
				return $content;
			}

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

			if ( $this->background_images ) {
				$content = $this->process_background_images( $content );
			}

			return $content;

        }

        protected function process_images( $content ) {

        	$images = WP_Smush_Page_Parser::get_images_from_content( $content );

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

			foreach ( $images[0] as $key => $image ) {
				$img_src   = $images['img_url'][ $key ];
				$new_image = $image;

				// Then update the image with correct CDN links.
				if ( $this->cdn ) {
					$new_image = WP_Smush::get_instance()->core()->mod->cdn->parse_image( $img_src, $new_image );
				}

				// First prepare for lazy-loading, as that does not require any URL rewrites.
				if ( $this->lazy_load ) {
					$new_image = $this->parse_image( $img_src, $new_image );					
				}

				$content = str_replace( $image, $new_image, $content );
			}

        	return $content;
        }


        public function parse_image( $src, $image ) {
			/**
			 * Filter to skip a single image from lazy load.
			 *
			 * @param bool   $skip  Should skip? Default: false.
			 * @param string $src   Image url.
			 */
			if ( apply_filters( 'smush_skip_image_from_lazy_load', false, $src ) ) {
				return $image;
			}

			$this->options = $this->settings->get_setting( WP_SMUSH_PREFIX . 'lazy_load' );

			// Avoid conflicts if attributes are set (another plugin, for example).
			if ( false !== strpos( $image, 'data-src' ) ) {
				return $image;
			}

			/**
			 * Check if some image formats are excluded.
			 */
			if ( in_array( false, $this->options['format'], true ) ) {
				$ext = strtolower( pathinfo( $src, PATHINFO_EXTENSION ) );
				$ext = 'jpg' === $ext ? 'jpeg' : $ext;

				if ( isset( $this->options['format'][ $ext ] ) && ! $this->options['format'][ $ext ] ) {
					return $image;
				}
			}

			if ( $this->has_excluded_class_or_id( $image ) ) {
				return $image;
			}

			$new_image = $image;

			$src = WP_Smush_Page_Parser::get_attribute( $new_image, 'src' );
			WP_Smush_Page_Parser::remove_attribute( $new_image, 'src' );
			WP_Smush_Page_Parser::add_attribute( $new_image, 'data-src', $src );

			// Change srcset to data-srcset attribute.
			//$new_image = preg_replace( '/<img(.*?)(srcset=)(.*?)>/i', '<img$1data-$2$3>', $new_image );

			// Add .lazyload class.
			$class = WP_Smush_Page_Parser::get_attribute( $new_image, 'class' );
			if ( $class ) {
				$class .= ' lazyload';
			} else {
				$class = 'lazyload';
			}
			WP_Smush_Page_Parser::remove_attribute( $new_image, 'class' );
			WP_Smush_Page_Parser::add_attribute( $new_image, 'class', apply_filters( 'wp_smush_lazy_load_classes', $class ) );

			WP_Smush_Page_Parser::add_attribute( $new_image, 'src', 'data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==' );

			// Use noscript element in HTML to load elements normally when JavaScript is disabled in browser.
			$new_image .= '<noscript>' . $image . '</noscript>';

			return $new_image;
		}


		private function has_excluded_class_or_id( $image ) {
			$image_classes = WP_Smush_Page_Parser::get_attribute( $image, 'class' );
			$image_classes = explode( ' ', $image_classes );
			$image_id      = '#' . WP_Smush_Page_Parser::get_attribute( $image, 'id' );

			if ( in_array( $image_id, $this->options['exclude-classes'], true ) ) {
				return true;
			}

			foreach ( $image_classes as $class ) {
				// Skip Revolution Slider images.
				if ( 'rev-slidebg' === $class ) {
					return true;
				}

				// Internal class to skip images.
				if ( 'no-lazyload' === $class ) {
					return true;
				}

				if ( in_array( ".{$class}", $this->options['exclude-classes'], true ) ) {
					return true;
				}
			}

			return false;
		}


		private function process_background_images( $content ) {
			$images = self::get_background_images( $content );

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

			foreach ( $images[0] as $key => $image ) {
				$img_src   = $images['img_url'][ $key ];
				$new_image = $image;

				// Update the image with correct CDN links.
				$new_image = WP_Smush::get_instance()->core()->mod->cdn->parse_background_image( $img_src, $new_image );

				$content = str_replace( $image, $new_image, $content );
			}

			return $content;
		}


		private static function get_background_images( $content ) {
			$images = array();

			if ( preg_match_all( '/(?:background-image:?\surl\([\'|"](?P<img_url>http?s?:?\/\/[^"\']*\.(?:png|jpg|jpeg|gif))[\'|"]\)?;){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 ] );
					}
				}
			}

			return $images;
		}

    }

    if ( ! function_exists( 'wpmudev_smush_bakery_carousel_excludes' ) ) {

        function wpmudev_smush_bakery_carousel_excludes() {
            return WPMUDEV_Smush_Bakery_Carousel_Excludes::get_instance();
        };

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

}