updated plugin W3 Total Cache version 2.5.0

wp-content/plugins/w3-total-cache/UserExperience_DeferScripts_Mutator.php

@@ -0,0 +1,175 @@
+<?php
+/**
+ * File: UserExperience_DeferScripts_Mutator.php
+ *
+ * JS feature mutator for buffer processing.
+ *
+ * @since 2.4.2
+ *
+ * @package W3TC
+ */
+
+namespace W3TC;
+
+/**
+ * UserExperience DeferScripts Mutator.
+ *
+ * @since 2.4.2
+ */
+class UserExperience_DeferScripts_Mutator {
+	/**
+	 * Config.
+	 *
+	 * @var object
+	 */
+	private $config;
+
+	/**
+	 * Modified flag.
+	 *
+	 * @var boolean
+	 */
+	private $modified = false;
+
+	/**
+	 * Array of includes.
+	 *
+	 * @var array
+	 */
+	private $includes = array();
+
+	/**
+	 * User Experience DeferScripts Mutator constructor.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @param object $config Config object.
+	 *
+	 * @return void
+	 */
+	public function __construct( $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * Runs User Experience DeferScripts Mutator.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @param string $buffer Buffer string containing browser output.
+	 *
+	 * @return string
+	 */
+	public function run( $buffer ) {
+		$r = apply_filters(
+			'w3tc_deferscripts_mutator_before',
+			array(
+				'buffer'   => $buffer,
+				'modified' => $this->modified,
+			)
+		);
+
+		$buffer         = $r['buffer'];
+		$this->modified = $r['modified'];
+
+		$this->includes = $this->config->get_array(
+			array(
+				'user-experience-defer-scripts',
+				'includes',
+			)
+		);
+
+		$buffer = preg_replace_callback(
+			'~<script\s[^>]+>~is',
+			array(
+				$this,
+				'tag_script',
+			),
+			$buffer
+		);
+
+		return $buffer;
+	}
+
+	/**
+	 * Get modified status flag.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @return boolean
+	 */
+	public function content_modified() {
+		return $this->modified;
+	}
+
+	/**
+	 * Modifies script tag for script matched to be deferred.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @param array $matches array of matched JS entries.
+	 *
+	 * @return string
+	 */
+	public function tag_script( $matches ) {
+		$content = $matches[0];
+
+		if ( $this->is_content_included( $content ) ) {
+			$count   = 0;
+			$content = preg_replace(
+				'~(\s)src=~is',
+				'$1data-lazy="w3tc" data-src=',
+				$content,
+				-1,
+				$count
+			);
+
+			if ( $count > 0 ) {
+				$this->modified = true;
+			}
+		}
+
+		return $content;
+	}
+
+	/**
+	 * Checks if content has already been deferred.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @param string $content script tag string.
+	 *
+	 * @return boolean
+	 */
+	private function is_content_included( $content ) {
+		foreach ( $this->includes as $w ) {
+			if ( ! empty( $w ) ) {
+				if ( strpos( $content, $w ) !== false ) {
+					return true;
+				}
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Filters out scripts so Minify doesn't touch deferred scripts.
+	 *
+	 * @since 2.4.2
+	 *
+	 * @param array $script_tags array of script tags.
+	 *
+	 * @return array
+	 */
+	public function w3tc_minify_js_script_tags( $script_tags ) {
+		return array_values(
+			array_filter(
+				$script_tags,
+				function( $i ) {
+					return ! preg_match( '~\sdata-lazy="w3tc"\s~', $i );
+				}
+			)
+		);
+	}
+}