#iU', $buffer, $tags_match ); if ( ! isset( $tags_match[0] ) ) { return $buffer; } foreach ( $tags_match[0] as $i => $tag ) { // Strip query args. $url = strtok( $tags_match[1][ $i ] , '?' ); $deferred_js_files = array_flip( get_rocket_deferred_js_files() ); // Check if this file should be deferred. if ( isset( $deferred_js_files[ $url ] ) ) { $deferred_tag = str_replace( '>', ' defer>', $tag ); $buffer = str_replace( $tag, $deferred_tag, $buffer ); } } return $buffer; } add_filter( 'rocket_buffer', 'rocket_insert_deferred_js', 11 ); /** * Defer all JS files. * * @since 2.10 * @author Remy Perona * * @param string $buffer HTML content. * @return string Updated HTML content */ function rocket_defer_js( $buffer ) { if ( ! get_rocket_option( 'defer_all_js' ) ) { return $buffer; } if ( is_rocket_post_excluded_option( 'defer_all_js' ) ) { return $buffer; } // Get all JS files with this regex. preg_match_all( '##iU', $buffer, $tags_match ); if ( ! isset( $tags_match[0] ) ) { return $buffer; } $exclude_defer_js = array_flip( get_rocket_exclude_defer_js() ); foreach ( $tags_match[0] as $i => $tag ) { // Strip query args. $path = parse_url( $tags_match[2][ $i ] , PHP_URL_PATH ); // Check if this file should be deferred. if ( isset( $exclude_defer_js[ $path ] ) ) { continue; } // Don't add defer if already async. if ( false !== strpos( $tags_match[1][ $i ], 'async' ) || false !== strpos( $tags_match[3][ $i ], 'async' ) ) { continue; } // Don't add defer if already defer. if ( false !== strpos( $tags_match[1][ $i ], 'defer' ) || false !== strpos( $tags_match[3][ $i ], 'defer' ) ) { continue; } $deferred_tag = str_replace( '>', ' defer>', $tag ); $buffer = str_replace( $tag, $deferred_tag, $buffer ); } return $buffer; } add_filter( 'rocket_buffer', 'rocket_defer_js', 14 );