3 * API for easily embedding rich media such as videos and images into content.
10 public $handlers = array();
12 public $usecache = true;
13 public $linkifunknown = true;
14 public $last_attr = array();
15 public $last_url = '';
18 * When a URL cannot be embedded, return false instead of returning a link
19 * or the URL. Bypasses the 'embed_maybe_make_link' filter.
21 public $return_false_on_fail = false;
26 public function __construct() {
27 // Hack to get the [embed] shortcode to run before wpautop()
28 add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
30 // Shortcode placeholder for strip_shortcodes()
31 add_shortcode( 'embed', '__return_false' );
33 // Attempts to embed all URLs in a post
34 add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
36 // After a post is saved, cache oEmbed items via AJAX
37 add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );
38 add_action( 'edit_page_form', array( $this, 'maybe_run_ajax_cache' ) );
42 * Process the [embed] shortcode.
44 * Since the [embed] shortcode needs to be run earlier than other shortcodes,
45 * this function removes all existing shortcodes, registers the [embed] shortcode,
46 * calls {@link do_shortcode()}, and then re-registers the old shortcodes.
48 * @global array $shortcode_tags
50 * @param string $content Content to parse
51 * @return string Content with shortcode parsed
53 public function run_shortcode( $content ) {
54 global $shortcode_tags;
56 // Back up current registered shortcodes and clear them all out
57 $orig_shortcode_tags = $shortcode_tags;
58 remove_all_shortcodes();
60 add_shortcode( 'embed', array( $this, 'shortcode' ) );
62 // Do the shortcode (only the [embed] one is registered)
63 $content = do_shortcode( $content, true );
65 // Put the original shortcodes back
66 $shortcode_tags = $orig_shortcode_tags;
72 * If a post/page was saved, then output JavaScript to make
73 * an AJAX request that will call WP_Embed::cache_oembed().
75 public function maybe_run_ajax_cache() {
78 if ( ! $post || empty( $_GET['message'] ) )
82 <script type="text/javascript">
83 jQuery(document).ready(function($){
84 $.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post->ID, 'relative' ); ?>");
91 * Register an embed handler. Do not use this function directly, use {@link wp_embed_register_handler()} instead.
92 * This function should probably also only be used for sites that do not support oEmbed.
94 * @param string $id An internal ID/name for the handler. Needs to be unique.
95 * @param string $regex The regex that will be used to see if this handler should be used for a URL.
96 * @param callable $callback The callback function that will be called if the regex is matched.
97 * @param int $priority Optional. Used to specify the order in which the registered handlers will be tested (default: 10). Lower numbers correspond with earlier testing, and handlers with the same priority are tested in the order in which they were added to the action.
99 public function register_handler( $id, $regex, $callback, $priority = 10 ) {
100 $this->handlers[$priority][$id] = array(
102 'callback' => $callback,
107 * Unregister a previously registered embed handler. Do not use this function directly, use {@link wp_embed_unregister_handler()} instead.
109 * @param string $id The handler ID that should be removed.
110 * @param int $priority Optional. The priority of the handler to be removed (default: 10).
112 public function unregister_handler( $id, $priority = 10 ) {
113 unset( $this->handlers[ $priority ][ $id ] );
117 * The {@link do_shortcode()} callback function.
119 * Attempts to convert a URL into embed HTML. Starts by checking the URL against the regex of the registered embed handlers.
120 * If none of the regex matches and it's enabled, then the URL will be given to the {@link WP_oEmbed} class.
122 * @param array $attr {
123 * Shortcode attributes. Optional.
125 * @type int $width Width of the embed in pixels.
126 * @type int $height Height of the embed in pixels.
128 * @param string $url The URL attempting to be embedded.
129 * @return string|false The embed HTML on success, otherwise the original URL.
130 * `->maybe_make_link()` can return false on failure.
132 public function shortcode( $attr, $url = '' ) {
135 if ( empty( $url ) && ! empty( $attr['src'] ) ) {
139 $this->last_url = $url;
141 if ( empty( $url ) ) {
142 $this->last_attr = $attr;
147 $attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );
149 $this->last_attr = $attr;
151 // kses converts & into & and we need to undo this
152 // See https://core.trac.wordpress.org/ticket/11311
153 $url = str_replace( '&', '&', $url );
155 // Look for known internal handlers
156 ksort( $this->handlers );
157 foreach ( $this->handlers as $priority => $handlers ) {
158 foreach ( $handlers as $id => $handler ) {
159 if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
160 if ( false !== $return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr ) )
162 * Filter the returned embed handler.
166 * @see WP_Embed::shortcode()
168 * @param mixed $return The shortcode callback function to call.
169 * @param string $url The attempted embed URL.
170 * @param array $attr An array of shortcode attributes.
172 return apply_filters( 'embed_handler_html', $return, $url, $attr );
177 $post_ID = ( ! empty( $post->ID ) ) ? $post->ID : null;
178 if ( ! empty( $this->post_ID ) ) // Potentially set by WP_Embed::cache_oembed()
179 $post_ID = $this->post_ID;
181 // Unknown URL format. Let oEmbed have a go.
184 // Check for a cached result (stored in the post meta)
185 $key_suffix = md5( $url . serialize( $attr ) );
186 $cachekey = '_oembed_' . $key_suffix;
187 $cachekey_time = '_oembed_time_' . $key_suffix;
190 * Filter the oEmbed TTL value (time to live).
194 * @param int $time Time to live (in seconds).
195 * @param string $url The attempted embed URL.
196 * @param array $attr An array of shortcode attributes.
197 * @param int $post_ID Post ID.
199 $ttl = apply_filters( 'oembed_ttl', DAY_IN_SECONDS, $url, $attr, $post_ID );
201 $cache = get_post_meta( $post_ID, $cachekey, true );
202 $cache_time = get_post_meta( $post_ID, $cachekey_time, true );
204 if ( ! $cache_time ) {
208 $cached_recently = ( time() - $cache_time ) < $ttl;
210 if ( $this->usecache || $cached_recently ) {
211 // Failures are cached. Serve one if we're using the cache.
212 if ( '{{unknown}}' === $cache )
213 return $this->maybe_make_link( $url );
215 if ( ! empty( $cache ) ) {
217 * Filter the cached oEmbed HTML.
221 * @see WP_Embed::shortcode()
223 * @param mixed $cache The cached HTML result, stored in post meta.
224 * @param string $url The attempted embed URL.
225 * @param array $attr An array of shortcode attributes.
226 * @param int $post_ID Post ID.
228 return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_ID );
233 * Filter whether to inspect the given URL for discoverable link tags.
236 * @since 4.4.0 The default value changed to true.
238 * @see WP_oEmbed::discover()
240 * @param bool $enable Whether to enable `<link>` tag discovery. Default true.
242 $attr['discover'] = ( apply_filters( 'embed_oembed_discover', true ) );
244 // Use oEmbed to get the HTML
245 $html = wp_oembed_get( $url, $attr );
247 // Maybe cache the result
249 update_post_meta( $post_ID, $cachekey, $html );
250 update_post_meta( $post_ID, $cachekey_time, time() );
251 } elseif ( ! $cache ) {
252 update_post_meta( $post_ID, $cachekey, '{{unknown}}' );
255 // If there was a result, return it
257 /** This filter is documented in wp-includes/class-wp-embed.php */
258 return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_ID );
263 return $this->maybe_make_link( $url );
267 * Delete all oEmbed caches. Unused by core as of 4.0.0.
269 * @param int $post_ID Post ID to delete the caches for.
271 public function delete_oembed_caches( $post_ID ) {
272 $post_metas = get_post_custom_keys( $post_ID );
273 if ( empty($post_metas) )
276 foreach ( $post_metas as $post_meta_key ) {
277 if ( '_oembed_' == substr( $post_meta_key, 0, 8 ) )
278 delete_post_meta( $post_ID, $post_meta_key );
283 * Triggers a caching of all oEmbed results.
285 * @param int $post_ID Post ID to do the caching for.
287 public function cache_oembed( $post_ID ) {
288 $post = get_post( $post_ID );
290 $post_types = get_post_types( array( 'show_ui' => true ) );
292 * Filter the array of post types to cache oEmbed results for.
296 * @param array $post_types Array of post types to cache oEmbed results for. Defaults to post types with `show_ui` set to true.
298 if ( empty( $post->ID ) || ! in_array( $post->post_type, apply_filters( 'embed_cache_oembed_types', $post_types ) ) ){
303 if ( ! empty( $post->post_content ) ) {
304 $this->post_ID = $post->ID;
305 $this->usecache = false;
307 $content = $this->run_shortcode( $post->post_content );
308 $this->autoembed( $content );
310 $this->usecache = true;
315 * Passes any unlinked URLs that are on their own line to {@link WP_Embed::shortcode()} for potential embedding.
317 * @uses WP_Embed::autoembed_callback()
319 * @param string $content The content to be searched.
320 * @return string Potentially modified $content.
322 public function autoembed( $content ) {
323 // Replace line breaks from all HTML elements with placeholders.
324 $content = wp_replace_in_html_tags( $content, array( "\n" => '<!-- wp-line-break -->' ) );
326 // Find URLs that are on their own line.
327 $content = preg_replace_callback( '|^(\s*)(https?://[^\s"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
329 // Put the line breaks back.
330 return str_replace( '<!-- wp-line-break -->', "\n", $content );
334 * Callback function for {@link WP_Embed::autoembed()}.
336 * @param array $match A regex match array.
337 * @return string The embed HTML on success, otherwise the original URL.
339 public function autoembed_callback( $match ) {
340 $oldval = $this->linkifunknown;
341 $this->linkifunknown = false;
342 $return = $this->shortcode( array(), $match[2] );
343 $this->linkifunknown = $oldval;
345 return $match[1] . $return . $match[3];
349 * Conditionally makes a hyperlink based on an internal class variable.
351 * @param string $url URL to potentially be linked.
352 * @return false|string Linked URL or the original URL. False if 'return_false_on_fail' is true.
354 public function maybe_make_link( $url ) {
355 if ( $this->return_false_on_fail ) {
359 $output = ( $this->linkifunknown ) ? '<a href="' . esc_url($url) . '">' . esc_html($url) . '</a>' : $url;
362 * Filter the returned, maybe-linked embed URL.
366 * @param string $output The linked or original URL.
367 * @param string $url The original URL.
369 return apply_filters( 'embed_maybe_make_link', $output, $url );
372 $GLOBALS['wp_embed'] = new WP_Embed();