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 an 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' ) );
41 * Process the [embed] shortcode.
43 * Since the [embed] shortcode needs to be run earlier than other shortcodes,
44 * this function removes all existing shortcodes, registers the [embed] shortcode,
45 * calls {@link do_shortcode()}, and then re-registers the old shortcodes.
47 * @global array $shortcode_tags
49 * @param string $content Content to parse
50 * @return string Content with shortcode parsed
52 public function run_shortcode( $content ) {
53 global $shortcode_tags;
55 // Back up current registered shortcodes and clear them all out
56 $orig_shortcode_tags = $shortcode_tags;
57 remove_all_shortcodes();
59 add_shortcode( 'embed', array( $this, 'shortcode' ) );
61 // Do the shortcode (only the [embed] one is registered)
62 $content = do_shortcode( $content, true );
64 // Put the original shortcodes back
65 $shortcode_tags = $orig_shortcode_tags;
71 * If a post/page was saved, then output JavaScript to make
72 * an AJAX request that will call WP_Embed::cache_oembed().
74 public function maybe_run_ajax_cache() {
77 if ( ! $post || empty( $_GET['message'] ) )
81 <script type="text/javascript">
82 jQuery(document).ready(function($){
83 $.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post->ID, 'relative' ); ?>");
90 * Register an embed handler. Do not use this function directly, use {@link wp_embed_register_handler()} instead.
91 * This function should probably also only be used for sites that do not support oEmbed.
93 * @param string $id An internal ID/name for the handler. Needs to be unique.
94 * @param string $regex The regex that will be used to see if this handler should be used for a URL.
95 * @param callable $callback The callback function that will be called if the regex is matched.
96 * @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.
98 public function register_handler( $id, $regex, $callback, $priority = 10 ) {
99 $this->handlers[$priority][$id] = array(
101 'callback' => $callback,
106 * Unregister a previously registered embed handler. Do not use this function directly, use {@link wp_embed_unregister_handler()} instead.
108 * @param string $id The handler ID that should be removed.
109 * @param int $priority Optional. The priority of the handler to be removed (default: 10).
111 public function unregister_handler( $id, $priority = 10 ) {
112 unset( $this->handlers[ $priority ][ $id ] );
116 * The {@link do_shortcode()} callback function.
118 * Attempts to convert a URL into embed HTML. Starts by checking the URL against the regex of the registered embed handlers.
119 * If none of the regex matches and it's enabled, then the URL will be given to the {@link WP_oEmbed} class.
121 * @param array $attr {
122 * Shortcode attributes. Optional.
124 * @type int $width Width of the embed in pixels.
125 * @type int $height Height of the embed in pixels.
127 * @param string $url The URL attempting to be embedded.
128 * @return string|false The embed HTML on success, otherwise the original URL.
129 * `->maybe_make_link()` can return false on failure.
131 public function shortcode( $attr, $url = '' ) {
134 if ( empty( $url ) && ! empty( $attr['src'] ) ) {
138 $this->last_url = $url;
140 if ( empty( $url ) ) {
141 $this->last_attr = $attr;
146 $attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );
148 $this->last_attr = $attr;
150 // kses converts & into & and we need to undo this
151 // See https://core.trac.wordpress.org/ticket/11311
152 $url = str_replace( '&', '&', $url );
154 // Look for known internal handlers
155 ksort( $this->handlers );
156 foreach ( $this->handlers as $priority => $handlers ) {
157 foreach ( $handlers as $id => $handler ) {
158 if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
159 if ( false !== $return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr ) )
161 * Filter the returned embed handler.
165 * @see WP_Embed::shortcode()
167 * @param mixed $return The shortcode callback function to call.
168 * @param string $url The attempted embed URL.
169 * @param array $attr An array of shortcode attributes.
171 return apply_filters( 'embed_handler_html', $return, $url, $attr );
176 $post_ID = ( ! empty( $post->ID ) ) ? $post->ID : null;
177 if ( ! empty( $this->post_ID ) ) // Potentially set by WP_Embed::cache_oembed()
178 $post_ID = $this->post_ID;
180 // Unknown URL format. Let oEmbed have a go.
183 // Check for a cached result (stored in the post meta)
184 $key_suffix = md5( $url . serialize( $attr ) );
185 $cachekey = '_oembed_' . $key_suffix;
186 $cachekey_time = '_oembed_time_' . $key_suffix;
189 * Filter the oEmbed TTL value (time to live).
193 * @param int $time Time to live (in seconds).
194 * @param string $url The attempted embed URL.
195 * @param array $attr An array of shortcode attributes.
196 * @param int $post_ID Post ID.
198 $ttl = apply_filters( 'oembed_ttl', DAY_IN_SECONDS, $url, $attr, $post_ID );
200 $cache = get_post_meta( $post_ID, $cachekey, true );
201 $cache_time = get_post_meta( $post_ID, $cachekey_time, true );
203 if ( ! $cache_time ) {
207 $cached_recently = ( time() - $cache_time ) < $ttl;
209 if ( $this->usecache || $cached_recently ) {
210 // Failures are cached. Serve one if we're using the cache.
211 if ( '{{unknown}}' === $cache )
212 return $this->maybe_make_link( $url );
214 if ( ! empty( $cache ) ) {
216 * Filter the cached oEmbed HTML.
220 * @see WP_Embed::shortcode()
222 * @param mixed $cache The cached HTML result, stored in post meta.
223 * @param string $url The attempted embed URL.
224 * @param array $attr An array of shortcode attributes.
225 * @param int $post_ID Post ID.
227 return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_ID );
232 * Filter whether to inspect the given URL for discoverable link tags.
236 * @see WP_oEmbed::discover()
238 * @param bool $enable Whether to enable `<link>` tag discovery. Default false.
240 $attr['discover'] = ( apply_filters( 'embed_oembed_discover', false ) && author_can( $post_ID, 'unfiltered_html' ) );
242 // Use oEmbed to get the HTML
243 $html = wp_oembed_get( $url, $attr );
245 // Maybe cache the result
247 update_post_meta( $post_ID, $cachekey, $html );
248 update_post_meta( $post_ID, $cachekey_time, time() );
249 } elseif ( ! $cache ) {
250 update_post_meta( $post_ID, $cachekey, '{{unknown}}' );
253 // If there was a result, return it
255 /** This filter is documented in wp-includes/class-wp-embed.php */
256 return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_ID );
261 return $this->maybe_make_link( $url );
265 * Delete all oEmbed caches. Unused by core as of 4.0.0.
267 * @param int $post_ID Post ID to delete the caches for.
269 public function delete_oembed_caches( $post_ID ) {
270 $post_metas = get_post_custom_keys( $post_ID );
271 if ( empty($post_metas) )
274 foreach( $post_metas as $post_meta_key ) {
275 if ( '_oembed_' == substr( $post_meta_key, 0, 8 ) )
276 delete_post_meta( $post_ID, $post_meta_key );
281 * Triggers a caching of all oEmbed results.
283 * @param int $post_ID Post ID to do the caching for.
285 public function cache_oembed( $post_ID ) {
286 $post = get_post( $post_ID );
288 $post_types = get_post_types( array( 'show_ui' => true ) );
290 * Filter the array of post types to cache oEmbed results for.
294 * @param array $post_types Array of post types to cache oEmbed results for. Defaults to post types with `show_ui` set to true.
296 if ( empty( $post->ID ) || ! in_array( $post->post_type, apply_filters( 'embed_cache_oembed_types', $post_types ) ) ){
301 if ( ! empty( $post->post_content ) ) {
302 $this->post_ID = $post->ID;
303 $this->usecache = false;
305 $content = $this->run_shortcode( $post->post_content );
306 $this->autoembed( $content );
308 $this->usecache = true;
313 * Passes any unlinked URLs that are on their own line to {@link WP_Embed::shortcode()} for potential embedding.
315 * @uses WP_Embed::autoembed_callback()
317 * @param string $content The content to be searched.
318 * @return string Potentially modified $content.
320 public function autoembed( $content ) {
321 // Replace line breaks from all HTML elements with placeholders.
322 $content = wp_replace_in_html_tags( $content, array( "\n" => '<!-- wp-line-break -->' ) );
324 // Find URLs that are on their own line.
325 $content = preg_replace_callback( '|^(\s*)(https?://[^\s"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
327 // Put the line breaks back.
328 return str_replace( '<!-- wp-line-break -->', "\n", $content );
332 * Callback function for {@link WP_Embed::autoembed()}.
334 * @param array $match A regex match array.
335 * @return string The embed HTML on success, otherwise the original URL.
337 public function autoembed_callback( $match ) {
338 $oldval = $this->linkifunknown;
339 $this->linkifunknown = false;
340 $return = $this->shortcode( array(), $match[2] );
341 $this->linkifunknown = $oldval;
343 return $match[1] . $return . $match[3];
347 * Conditionally makes a hyperlink based on an internal class variable.
349 * @param string $url URL to potentially be linked.
350 * @return false|string Linked URL or the original URL. False if 'return_false_on_fail' is true.
352 public function maybe_make_link( $url ) {
353 if ( $this->return_false_on_fail ) {
357 $output = ( $this->linkifunknown ) ? '<a href="' . esc_url($url) . '">' . esc_html($url) . '</a>' : $url;
360 * Filter the returned, maybe-linked embed URL.
364 * @param string $output The linked or original URL.
365 * @param string $url The original URL.
367 return apply_filters( 'embed_maybe_make_link', $output, $url );
370 $GLOBALS['wp_embed'] = new WP_Embed();