Your IP : 216.73.216.5
<?php
/**
* File: UserExperience_LazyLoad_Plugin.php
*
* @package W3TC
*/
namespace W3TC;
/**
* Class UserExperience_LazyLoad_Plugin
*/
class UserExperience_LazyLoad_Plugin {
/**
* Configuration object for lazy loading plugin.
*
* @var Config
*/
private $config;
/**
* Mapping of attachment URLs to post IDs.
*
* @var array
*/
private $posts_by_url = array();
/**
* Constructor to initialize the UserExperience_LazyLoad_Plugin class.
*
* Sets up the configuration object for managing plugin settings.
*
* @return void
*/
public function __construct() {
$this->config = Dispatcher::config();
}
/**
* Runs the lazy loading plugin.
*
* Initializes output buffer callbacks, hooks for various Google Maps plugins,
* and registers necessary WordPress filters.
*
* @return void
*/
public function run() {
Util_Bus::add_ob_callback( 'lazyload', array( $this, 'ob_callback' ) );
$this->metaslider_hooks();
if ( $this->config->get_boolean( 'lazyload.googlemaps.google_maps_easy' ) ) {
$p = new UserExperience_LazyLoad_GoogleMaps_GoogleMapsEasy();
add_filter( 'w3tc_lazyload_mutator_before', array( $p, 'w3tc_lazyload_mutator_before' ) );
}
if ( $this->config->get_boolean( 'lazyload.googlemaps.wp_google_maps' ) ) {
add_filter(
'w3tc_lazyload_mutator_before',
array(
new UserExperience_LazyLoad_GoogleMaps_WPGoogleMaps(),
'w3tc_lazyload_mutator_before',
)
);
}
if ( $this->config->get_boolean( 'lazyload.googlemaps.wp_google_map_plugin' ) ) {
$p = new UserExperience_LazyLoad_GoogleMaps_WPGoogleMapPlugin();
add_filter( 'w3tc_lazyload_mutator_before', array( $p, 'w3tc_lazyload_mutator_before' ) );
}
add_filter( 'wp_get_attachment_url', array( $this, 'wp_get_attachment_url' ), 10, 2 );
add_filter( 'w3tc_footer_comment', array( $this, 'w3tc_footer_comment' ) );
}
/**
* Output buffer callback for processing HTML content.
*
* Modifies the HTML buffer to include lazy loading functionality, embeds the
* lazy loading script, and processes content through a mutator.
*
* @param string $buffer The output buffer content.
*
* @return string The modified or unmodified buffer content.
*/
public function ob_callback( $buffer ) {
if ( '' === $buffer || ! \W3TC\Util_Content::is_html_xml( $buffer ) ) {
return $buffer;
}
$can_process = array(
'enabled' => true,
'buffer' => $buffer,
'reason' => null,
);
$can_process = $this->can_process( $can_process );
$can_process = apply_filters( 'w3tc_lazyload_can_process', $can_process );
// set reject reason in comment.
if ( $can_process['enabled'] ) {
$reject_reason = '';
} else {
$reject_reason = empty( $can_process['reason'] ) ? ' (not specified)' : ' (' . $can_process['reason'] . ')';
}
$buffer = str_replace( '{w3tc_lazyload_reject_reason}', $reject_reason, $buffer );
// processing.
if ( ! $can_process['enabled'] ) {
return $buffer;
}
$mutator = new UserExperience_LazyLoad_Mutator( $this->config, $this->posts_by_url );
$buffer = $mutator->run( $buffer );
// embed lazyload script.
if ( $mutator->content_modified() ) {
$buffer = apply_filters( 'w3tc_lazyload_embed_script', $buffer );
$is_embed_script = apply_filters( 'w3tc_lazyload_is_embed_script', true );
if ( $is_embed_script ) {
$buffer = $this->embed_script( $buffer );
}
}
return $buffer;
}
/**
* Checks if lazy loading can process the current request.
*
* Determines if lazy loading should be enabled based on context such as
* admin area, feed, or short initialization.
*
* @param array $can_process Array with processing status, buffer content, and reason.
*
* @return array Updated array with processing status and reason.
*/
private function can_process( $can_process ) {
if ( defined( 'WP_ADMIN' ) ) {
$can_process['enabled'] = false;
$can_process['reason'] = 'WP_ADMIN';
return $can_process;
}
if ( defined( 'SHORTINIT' ) && SHORTINIT ) {
$can_process['enabled'] = false;
$can_process['reason'] = 'SHORTINIT';
return $can_process;
}
if ( function_exists( 'is_feed' ) && is_feed() ) {
$can_process['enabled'] = false;
$can_process['reason'] = 'feed';
return $can_process;
}
return $can_process;
}
/**
* Appends a lazy loading footer comment to strings.
*
* Adds a footer comment indicating the use of lazy loading and any reject reasons.
*
* @param array $strings Existing footer comments.
*
* @return array Modified footer comments.
*/
public function w3tc_footer_comment( $strings ) {
$strings[] = __( 'Lazy Loading', 'w3-total-cache' ) . '{w3tc_lazyload_reject_reason}';
return $strings;
}
/**
* Embeds the lazy loading script into the HTML content.
*
* Adds the lazy loading JavaScript code and configuration to the appropriate
* section of the HTML buffer.
*
* phpcs:disable WordPress.WP.EnqueuedResources.NonEnqueuedScript
* phpcs:disable WordPress.WP.AlternativeFunctions
*
* @param string $buffer The HTML content buffer.
*
* @return string The modified buffer with the embedded script.
*/
private function embed_script( $buffer ) {
$js_url = plugins_url( 'pub/js/lazyload.min.js', W3TC_FILE );
$method = $this->config->get_string( 'lazyload.embed_method' );
$fire_event = 'function(t){var e;try{e=new CustomEvent("w3tc_lazyload_loaded",{detail:{e:t}})}catch(a){(e=document.createEvent("CustomEvent")).initCustomEvent("w3tc_lazyload_loaded",!1,!1,{e:t})}window.dispatchEvent(e)}';
$thresholds = '';
$config_threshold = $this->config->get_string( 'lazyload.threshold' );
if ( ! empty( $config_threshold ) ) {
$thresholds = 'thresholds:' . wp_json_encode( $config_threshold ) . ',';
}
$config = '{elements_selector:".lazy",' . $thresholds . 'callback_loaded:' . $fire_event . '}';
$on_initialized_javascript = apply_filters( 'w3tc_lazyload_on_initialized_javascript', '' );
if ( 'async_head' === $method ) {
$on_initialized_javascript_wrapped = '';
if ( ! empty( $on_initialized_javascript ) ) {
// LazyLoad::Initialized fired just before making LazyLoad global so next execution cycle have it.
$on_initialized_javascript_wrapped =
'window.addEventListener("LazyLoad::Initialized", function(){' .
'setTimeout(function() {' .
$on_initialized_javascript .
'}, 1);' .
'});';
}
$embed_script =
'<style>img.lazy{min-height:1px}</style>' .
'<link href="' . esc_url( $js_url ) . '" as="script">';
$buffer = preg_replace(
'~<head(\s+[^>]*)*>~Ui',
'\\0' . $embed_script,
$buffer,
1
);
// load lazyload in footer to make sure DOM is ready at the moment of initialization.
$footer_script =
'<script>' .
$on_initialized_javascript_wrapped .
'window.w3tc_lazyload=1,' .
'window.lazyLoadOptions=' . $config .
'</script>' .
'<script async src="' . esc_url( $js_url ) . '"></script>';
$buffer = preg_replace(
'~</body(\s+[^>]*)*>~Ui',
$footer_script . '\\0',
$buffer,
1
);
} elseif ( 'inline_footer' === $method ) {
$footer_script =
'<style>img.lazy{min-height:1px}</style>' .
'<script>' .
file_get_contents( W3TC_DIR . '/pub/js/lazyload.min.js' ) .
'window.w3tc_lazyload=new LazyLoad(' . $config . ');' .
$on_initialized_javascript .
'</script>';
$buffer = preg_replace(
'~</body(\s+[^>]*)*>~Ui',
$footer_script . '\\0',
$buffer,
1
);
} else { // 'sync_head'
$head_script =
'<style>img.lazy{min-height:1px}</style>' .
'<script src="' . esc_url( $js_url ) . '"></script>';
$buffer = preg_replace(
'~<head(\s+[^>]*)*>~Ui',
'\\0' . $head_script,
$buffer,
1
);
$footer_script =
'<script>' .
'window.w3tc_lazyload=new LazyLoad(' . $config . ');' .
$on_initialized_javascript .
'</script>';
$buffer = preg_replace(
'~</body(\s+[^>]*)*>~Ui',
$footer_script . '\\0',
$buffer,
1
);
}
return $buffer;
}
/**
* Maps attachment URLs to their corresponding post IDs.
*
* Updates the internal posts-by-URL mapping for tracking purposes.
*
* @param string $url The attachment URL.
* @param int $post_id The post ID.
*
* @return string The unmodified attachment URL.
*/
public function wp_get_attachment_url( $url, $post_id ) {
$this->posts_by_url[ $url ] = $post_id;
return $url;
}
/**
* Adds hooks specific to MetaSlider plugin compatibility.
*
* Modifies MetaSlider content to work seamlessly with lazy loading.
*
* @return void
*/
private function metaslider_hooks() {
add_filter( 'metaslider_nivo_slider_get_html', array( $this, 'metaslider_nivo_slider_get_html' ) );
}
/**
* Filters MetaSlider HTML output for compatibility.
*
* Prevents lazy loading from interfering with MetaSlider's image loading
* by adding a `no-lazy` class to images.
*
* @param string $content The MetaSlider HTML content.
*
* @return string Modified HTML content.
*/
public function metaslider_nivo_slider_get_html( $content ) {
// nivo slider use "src" attr of <img> tags to populate
// own image via JS, i.e. cant be replaced by lazyloading.
$content = preg_replace(
'~(\s+)(class=)([\"\'])(.*?)([\"\'])~',
'$1$2$3$4 no-lazy$5',
$content
);
return $content;
}
}