wp/wp-includes/class-wp-embed.php
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     1 <?php
       
     2 /**
       
     3  * API for easily embedding rich media such as videos and images into content.
       
     4  *
       
     5  * @package WordPress
       
     6  * @subpackage Embed
       
     7  * @since 2.9.0
       
     8  */
       
     9 class WP_Embed {
       
    10 	var $handlers = array();
       
    11 	var $post_ID;
       
    12 	var $usecache = true;
       
    13 	var $linkifunknown = true;
       
    14 
       
    15 	/**
       
    16 	 * Constructor
       
    17 	 */
       
    18 	function __construct() {
       
    19 		// Hack to get the [embed] shortcode to run before wpautop()
       
    20 		add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
       
    21 
       
    22 		// Shortcode placeholder for strip_shortcodes()
       
    23 		add_shortcode( 'embed', '__return_false' );
       
    24 
       
    25 		// Attempts to embed all URLs in a post
       
    26 		add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
       
    27 
       
    28 		// When a post is saved, invalidate the oEmbed cache
       
    29 		add_action( 'pre_post_update', array( $this, 'delete_oembed_caches' ) );
       
    30 
       
    31 		// After a post is saved, cache oEmbed items via AJAX
       
    32 		add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );
       
    33 	}
       
    34 
       
    35 	/**
       
    36 	 * Process the [embed] shortcode.
       
    37 	 *
       
    38 	 * Since the [embed] shortcode needs to be run earlier than other shortcodes,
       
    39 	 * this function removes all existing shortcodes, registers the [embed] shortcode,
       
    40 	 * calls {@link do_shortcode()}, and then re-registers the old shortcodes.
       
    41 	 *
       
    42 	 * @uses $shortcode_tags
       
    43 	 * @uses remove_all_shortcodes()
       
    44 	 * @uses add_shortcode()
       
    45 	 * @uses do_shortcode()
       
    46 	 *
       
    47 	 * @param string $content Content to parse
       
    48 	 * @return string Content with shortcode parsed
       
    49 	 */
       
    50 	function run_shortcode( $content ) {
       
    51 		global $shortcode_tags;
       
    52 
       
    53 		// Back up current registered shortcodes and clear them all out
       
    54 		$orig_shortcode_tags = $shortcode_tags;
       
    55 		remove_all_shortcodes();
       
    56 
       
    57 		add_shortcode( 'embed', array( $this, 'shortcode' ) );
       
    58 
       
    59 		// Do the shortcode (only the [embed] one is registered)
       
    60 		$content = do_shortcode( $content );
       
    61 
       
    62 		// Put the original shortcodes back
       
    63 		$shortcode_tags = $orig_shortcode_tags;
       
    64 
       
    65 		return $content;
       
    66 	}
       
    67 
       
    68 	/**
       
    69 	 * If a post/page was saved, then output JavaScript to make
       
    70 	 * an AJAX request that will call WP_Embed::cache_oembed().
       
    71 	 */
       
    72 	function maybe_run_ajax_cache() {
       
    73 		$post = get_post();
       
    74 
       
    75 		if ( ! $post || empty($_GET['message']) || 1 != $_GET['message'] )
       
    76 			return;
       
    77 
       
    78 ?>
       
    79 <script type="text/javascript">
       
    80 /* <![CDATA[ */
       
    81 	jQuery(document).ready(function($){
       
    82 		$.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post->ID, 'relative' ); ?>");
       
    83 	});
       
    84 /* ]]> */
       
    85 </script>
       
    86 <?php
       
    87 	}
       
    88 
       
    89 	/**
       
    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.
       
    92 	 *
       
    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 callback $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.
       
    97 	 */
       
    98 	function register_handler( $id, $regex, $callback, $priority = 10 ) {
       
    99 		$this->handlers[$priority][$id] = array(
       
   100 			'regex'    => $regex,
       
   101 			'callback' => $callback,
       
   102 		);
       
   103 	}
       
   104 
       
   105 	/**
       
   106 	 * Unregister a previously registered embed handler. Do not use this function directly, use {@link wp_embed_unregister_handler()} instead.
       
   107 	 *
       
   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).
       
   110 	 */
       
   111 	function unregister_handler( $id, $priority = 10 ) {
       
   112 		if ( isset($this->handlers[$priority][$id]) )
       
   113 			unset($this->handlers[$priority][$id]);
       
   114 	}
       
   115 
       
   116 	/**
       
   117 	 * The {@link do_shortcode()} callback function.
       
   118 	 *
       
   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.
       
   121 	 *
       
   122 	 * @uses wp_oembed_get()
       
   123 	 * @uses wp_parse_args()
       
   124 	 * @uses wp_embed_defaults()
       
   125 	 * @uses WP_Embed::maybe_make_link()
       
   126 	 * @uses get_option()
       
   127 	 * @uses author_can()
       
   128 	 * @uses wp_cache_get()
       
   129 	 * @uses wp_cache_set()
       
   130 	 * @uses get_post_meta()
       
   131 	 * @uses update_post_meta()
       
   132 	 *
       
   133 	 * @param array $attr Shortcode attributes.
       
   134 	 * @param string $url The URL attempting to be embedded.
       
   135 	 * @return string The embed HTML on success, otherwise the original URL.
       
   136 	 */
       
   137 	function shortcode( $attr, $url = '' ) {
       
   138 		$post = get_post();
       
   139 
       
   140 		if ( empty( $url ) )
       
   141 			return '';
       
   142 
       
   143 		$rawattr = $attr;
       
   144 		$attr = wp_parse_args( $attr, wp_embed_defaults() );
       
   145 
       
   146 		// kses converts & into &amp; and we need to undo this
       
   147 		// See http://core.trac.wordpress.org/ticket/11311
       
   148 		$url = str_replace( '&amp;', '&', $url );
       
   149 
       
   150 		// Look for known internal handlers
       
   151 		ksort( $this->handlers );
       
   152 		foreach ( $this->handlers as $priority => $handlers ) {
       
   153 			foreach ( $handlers as $id => $handler ) {
       
   154 				if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
       
   155 					if ( false !== $return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr ) )
       
   156 						/**
       
   157 						 * Filter the returned embed handler.
       
   158 						 *
       
   159 						 * @since 2.9.0
       
   160 						 *
       
   161 						 * @param mixed  $return The shortcode callback function to call.
       
   162 						 * @param string $url    The attempted embed URL.
       
   163 						 * @param array  $attr   An array of shortcode attributes.
       
   164 						 */
       
   165 						return apply_filters( 'embed_handler_html', $return, $url, $attr );
       
   166 				}
       
   167 			}
       
   168 		}
       
   169 
       
   170 		$post_ID = ( ! empty( $post->ID ) ) ? $post->ID : null;
       
   171 		if ( ! empty( $this->post_ID ) ) // Potentially set by WP_Embed::cache_oembed()
       
   172 			$post_ID = $this->post_ID;
       
   173 
       
   174 		// Unknown URL format. Let oEmbed have a go.
       
   175 		if ( $post_ID ) {
       
   176 
       
   177 			// Check for a cached result (stored in the post meta)
       
   178 			$cachekey = '_oembed_' . md5( $url . serialize( $attr ) );
       
   179 			if ( $this->usecache ) {
       
   180 				$cache = get_post_meta( $post_ID, $cachekey, true );
       
   181 
       
   182 				// Failures are cached
       
   183 				if ( '{{unknown}}' === $cache )
       
   184 					return $this->maybe_make_link( $url );
       
   185 
       
   186 				if ( ! empty( $cache ) )
       
   187 					/**
       
   188 					 * Filter the cached oEmbed HTML.
       
   189 					 *
       
   190 					 * @since 2.9.0
       
   191 					 *
       
   192 					 * @param mixed  $cache   The cached HTML result, stored in post meta.
       
   193 					 * @param string $url     The attempted embed URL.
       
   194 					 * @param array  $attr    An array of shortcode attributes.
       
   195 					 * @param int    $post_ID Post ID.
       
   196 					 */
       
   197 					return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_ID );
       
   198 			}
       
   199 
       
   200 			/**
       
   201 			 * Filter whether to inspect the given URL for discoverable <link> tags.
       
   202 			 *
       
   203 			 * @see WP_oEmbed::discover()
       
   204 			 *
       
   205 			 * @param bool false Whether to enable <link> tag discovery. Default false.
       
   206 			 */
       
   207 			$attr['discover'] = ( apply_filters( 'embed_oembed_discover', false ) && author_can( $post_ID, 'unfiltered_html' ) );
       
   208 
       
   209 			// Use oEmbed to get the HTML
       
   210 			$html = wp_oembed_get( $url, $attr );
       
   211 
       
   212 			// Cache the result
       
   213 			$cache = ( $html ) ? $html : '{{unknown}}';
       
   214 			update_post_meta( $post_ID, $cachekey, $cache );
       
   215 
       
   216 			// If there was a result, return it
       
   217 			if ( $html ) {
       
   218 				/** This filter is documented in wp-includes/class-wp-embed.php */
       
   219 				return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_ID );
       
   220 			}
       
   221 		}
       
   222 
       
   223 		// Still unknown
       
   224 		return $this->maybe_make_link( $url );
       
   225 	}
       
   226 
       
   227 	/**
       
   228 	 * Delete all oEmbed caches.
       
   229 	 *
       
   230 	 * @param int $post_ID Post ID to delete the caches for.
       
   231 	 */
       
   232 	function delete_oembed_caches( $post_ID ) {
       
   233 		$post_metas = get_post_custom_keys( $post_ID );
       
   234 		if ( empty($post_metas) )
       
   235 			return;
       
   236 
       
   237 		foreach( $post_metas as $post_meta_key ) {
       
   238 			if ( '_oembed_' == substr( $post_meta_key, 0, 8 ) )
       
   239 				delete_post_meta( $post_ID, $post_meta_key );
       
   240 		}
       
   241 	}
       
   242 
       
   243 	/**
       
   244 	 * Triggers a caching of all oEmbed results.
       
   245 	 *
       
   246 	 * @param int $post_ID Post ID to do the caching for.
       
   247 	 */
       
   248 	function cache_oembed( $post_ID ) {
       
   249 		$post = get_post( $post_ID );
       
   250 
       
   251 		$post_types = array( 'post', 'page' );
       
   252 		/**
       
   253 		 * Filter the array of post types to cache oEmbed results for.
       
   254 		 *
       
   255 		 * @since 2.9.0
       
   256 		 *
       
   257 		 * @param array $post_types Array of post types to cache oEmbed results for. Default 'post', 'page'.
       
   258 		 */
       
   259 		if ( empty($post->ID) || !in_array( $post->post_type, apply_filters( 'embed_cache_oembed_types', $post_types ) ) )
       
   260 			return;
       
   261 
       
   262 		// Trigger a caching
       
   263 		if ( !empty($post->post_content) ) {
       
   264 			$this->post_ID = $post->ID;
       
   265 			$this->usecache = false;
       
   266 
       
   267 			$content = $this->run_shortcode( $post->post_content );
       
   268 			$this->autoembed( $content );
       
   269 
       
   270 			$this->usecache = true;
       
   271 		}
       
   272 	}
       
   273 
       
   274 	/**
       
   275 	 * Passes any unlinked URLs that are on their own line to {@link WP_Embed::shortcode()} for potential embedding.
       
   276 	 *
       
   277 	 * @uses WP_Embed::autoembed_callback()
       
   278 	 *
       
   279 	 * @param string $content The content to be searched.
       
   280 	 * @return string Potentially modified $content.
       
   281 	 */
       
   282 	function autoembed( $content ) {
       
   283 		return preg_replace_callback( '|^\s*(https?://[^\s"]+)\s*$|im', array( $this, 'autoembed_callback' ), $content );
       
   284 	}
       
   285 
       
   286 	/**
       
   287 	 * Callback function for {@link WP_Embed::autoembed()}.
       
   288 	 *
       
   289 	 * @uses WP_Embed::shortcode()
       
   290 	 *
       
   291 	 * @param array $match A regex match array.
       
   292 	 * @return string The embed HTML on success, otherwise the original URL.
       
   293 	 */
       
   294 	function autoembed_callback( $match ) {
       
   295 		$oldval = $this->linkifunknown;
       
   296 		$this->linkifunknown = false;
       
   297 		$return = $this->shortcode( array(), $match[1] );
       
   298 		$this->linkifunknown = $oldval;
       
   299 
       
   300 		return "\n$return\n";
       
   301 	}
       
   302 
       
   303 	/**
       
   304 	 * Conditionally makes a hyperlink based on an internal class variable.
       
   305 	 *
       
   306 	 * @param string $url URL to potentially be linked.
       
   307 	 * @return string Linked URL or the original URL.
       
   308 	 */
       
   309 	function maybe_make_link( $url ) {
       
   310 		$output = ( $this->linkifunknown ) ? '<a href="' . esc_url($url) . '">' . esc_html($url) . '</a>' : $url;
       
   311 
       
   312 		/**
       
   313 		 * Filter the returned, maybe-linked embed URL.
       
   314 		 *
       
   315 		 * @since 2.9.0
       
   316 		 *
       
   317 		 * @param string $output The linked or original URL.
       
   318 		 * @param string $url    The original URL.
       
   319 		 */
       
   320 		return apply_filters( 'embed_maybe_make_link', $output, $url );
       
   321 	}
       
   322 }
       
   323 $GLOBALS['wp_embed'] = new WP_Embed();