Wordpress 4.6
[autoinstalls/wordpress.git] / wp-includes / class-oembed.php
index 6042fd4332630dd5423a7298db1eddf8b820955a..9790d266f67b6532410ac24adcb16df80f3331a2 100644 (file)
@@ -1,9 +1,10 @@
 <?php
 /**
- * API for fetching the HTML to embed remote content based on a provided URL.
- * Used internally by the {@link WP_Embed} class, but is designed to be generic.
+ * API for fetching the HTML to embed remote content based on a provided URL
  *
- * @link http://codex.wordpress.org/oEmbed oEmbed Codex Article
+ * Used internally by the WP_Embed class, but is designed to be generic.
+ *
+ * @link https://codex.wordpress.org/oEmbed oEmbed Codex Article
  * @link http://oembed.com/ oEmbed Homepage
  *
  * @package WordPress
  */
 
 /**
- * oEmbed class.
+ * Core class used to implement oEmbed functionality.
  *
- * @package WordPress
- * @subpackage oEmbed
  * @since 2.9.0
  */
 class WP_oEmbed {
+
+       /**
+        * A list of oEmbed providers.
+        *
+        * @since 2.9.0
+        * @access public
+        * @var array
+        */
        public $providers = array();
+
+       /**
+        * A list of an early oEmbed providers.
+        *
+        * @since 4.0.0
+        * @access public
+        * @static
+        * @var array
+        */
        public static $early_providers = array();
 
        /**
-        * Constructor
+        * A list of private/protected methods, used for backward compatibility.
+        *
+        * @since 4.2.0
+        * @access private
+        * @var array
+        */
+       private $compat_methods = array( '_fetch_with_format', '_parse_json', '_parse_xml', '_parse_body' );
+
+       /**
+        * Constructor.
         *
         * @since 2.9.0
+        * @access public
         */
        public function __construct() {
+               $host = urlencode( home_url() );
                $providers = array(
-                       '#http://(www\.)?youtube\.com/watch.*#i'              => array( 'http://www.youtube.com/oembed',                      true  ),
-                       '#https://(www\.)?youtube\.com/watch.*#i'             => array( 'http://www.youtube.com/oembed?scheme=https',         true  ),
-                       '#http://(www\.)?youtube\.com/playlist.*#i'           => array( 'http://www.youtube.com/oembed',                      true  ),
-                       '#https://(www\.)?youtube\.com/playlist.*#i'          => array( 'http://www.youtube.com/oembed?scheme=https',         true  ),
-                       '#http://youtu\.be/.*#i'                              => array( 'http://www.youtube.com/oembed',                      true  ),
-                       '#https://youtu\.be/.*#i'                             => array( 'http://www.youtube.com/oembed?scheme=https',         true  ),
-                       'http://blip.tv/*'                                    => array( 'http://blip.tv/oembed/',                             false ),
-                       '#https?://(.+\.)?vimeo\.com/.*#i'                    => array( 'http://vimeo.com/api/oembed.{format}',               true  ),
-                       '#https?://(www\.)?dailymotion\.com/.*#i'             => array( 'http://www.dailymotion.com/services/oembed',         true  ),
-                       'http://dai.ly/*'                                     => array( 'http://www.dailymotion.com/services/oembed',         false ),
-                       '#https?://(www\.)?flickr\.com/.*#i'                  => array( 'https://www.flickr.com/services/oembed/',            true  ),
-                       '#https?://flic\.kr/.*#i'                             => array( 'https://www.flickr.com/services/oembed/',            true  ),
-                       '#https?://(.+\.)?smugmug\.com/.*#i'                  => array( 'http://api.smugmug.com/services/oembed/',            true  ),
-                       '#https?://(www\.)?hulu\.com/watch/.*#i'              => array( 'http://www.hulu.com/api/oembed.{format}',            true  ),
-                       'http://revision3.com/*'                              => array( 'http://revision3.com/api/oembed/',                   false ),
-                       'http://i*.photobucket.com/albums/*'                  => array( 'http://photobucket.com/oembed',                      false ),
-                       'http://gi*.photobucket.com/groups/*'                 => array( 'http://photobucket.com/oembed',                      false ),
-                       '#https?://(www\.)?scribd\.com/doc/.*#i'              => array( 'http://www.scribd.com/services/oembed',              true  ),
-                       '#https?://wordpress.tv/.*#i'                         => array( 'http://wordpress.tv/oembed/',                        true ),
-                       '#https?://(.+\.)?polldaddy\.com/.*#i'                => array( 'https://polldaddy.com/oembed/',                      true  ),
-                       '#https?://poll\.fm/.*#i'                             => array( 'https://polldaddy.com/oembed/',                      true  ),
-                       '#https?://(www\.)?funnyordie\.com/videos/.*#i'       => array( 'http://www.funnyordie.com/oembed',                   true  ),
-                       '#https?://(www\.)?twitter\.com/.+?/status(es)?/.*#i' => array( 'https://api.twitter.com/1/statuses/oembed.{format}', true  ),
-                       '#https?://vine.co/v/.*#i'                            => array( 'https://vine.co/oembed.{format}',                    true  ),
-                       '#https?://(www\.)?soundcloud\.com/.*#i'              => array( 'http://soundcloud.com/oembed',                       true  ),
-                       '#https?://(.+?\.)?slideshare\.net/.*#i'              => array( 'https://www.slideshare.net/api/oembed/2',            true  ),
-                       '#http://instagr(\.am|am\.com)/p/.*#i'                => array( 'http://api.instagram.com/oembed',                    true  ),
-                       '#https?://(www\.)?rdio\.com/.*#i'                    => array( 'http://www.rdio.com/api/oembed/',                    true  ),
-                       '#https?://rd\.io/x/.*#i'                             => array( 'http://www.rdio.com/api/oembed/',                    true  ),
-                       '#https?://(open|play)\.spotify\.com/.*#i'            => array( 'https://embed.spotify.com/oembed/',                  true  ),
-                       '#https?://(.+\.)?imgur\.com/.*#i'                    => array( 'http://api.imgur.com/oembed',                        true  ),
-                       '#https?://(www\.)?meetu(\.ps|p\.com)/.*#i'           => array( 'http://api.meetup.com/oembed',                       true  ),
-                       '#https?://(www\.)?issuu\.com/.+/docs/.+#i'           => array( 'http://issuu.com/oembed_wp',                         true  ),
-                       '#https?://(www\.)?collegehumor\.com/video/.*#i'      => array( 'http://www.collegehumor.com/oembed.{format}',        true  ),
-                       '#https?://(www\.)?mixcloud\.com/.*#i'                => array( 'http://www.mixcloud.com/oembed',                     true  ),
-                       '#https?://(www\.|embed\.)?ted\.com/talks/.*#i'       => array( 'http://www.ted.com/talks/oembed.{format}',           true  ),
-                       '#https?://(www\.)?(animoto|video214)\.com/play/.*#i' => array( 'http://animoto.com/oembeds/create',                  true  ),
+                       '#http://((m|www)\.)?youtube\.com/watch.*#i'          => array( 'http://www.youtube.com/oembed',                             true  ),
+                       '#https://((m|www)\.)?youtube\.com/watch.*#i'         => array( 'http://www.youtube.com/oembed?scheme=https',                true  ),
+                       '#http://((m|www)\.)?youtube\.com/playlist.*#i'       => array( 'http://www.youtube.com/oembed',                             true  ),
+                       '#https://((m|www)\.)?youtube\.com/playlist.*#i'      => array( 'http://www.youtube.com/oembed?scheme=https',                true  ),
+                       '#http://youtu\.be/.*#i'                              => array( 'http://www.youtube.com/oembed',                             true  ),
+                       '#https://youtu\.be/.*#i'                             => array( 'http://www.youtube.com/oembed?scheme=https',                true  ),
+                       '#https?://(.+\.)?vimeo\.com/.*#i'                    => array( 'http://vimeo.com/api/oembed.{format}',                      true  ),
+                       '#https?://(www\.)?dailymotion\.com/.*#i'             => array( 'https://www.dailymotion.com/services/oembed',               true  ),
+                       '#https?://dai.ly/.*#i'                               => array( 'https://www.dailymotion.com/services/oembed',               true  ),
+                       '#https?://(www\.)?flickr\.com/.*#i'                  => array( 'https://www.flickr.com/services/oembed/',                   true  ),
+                       '#https?://flic\.kr/.*#i'                             => array( 'https://www.flickr.com/services/oembed/',                   true  ),
+                       '#https?://(.+\.)?smugmug\.com/.*#i'                  => array( 'http://api.smugmug.com/services/oembed/',                   true  ),
+                       '#https?://(www\.)?hulu\.com/watch/.*#i'              => array( 'http://www.hulu.com/api/oembed.{format}',                   true  ),
+                       'http://i*.photobucket.com/albums/*'                  => array( 'http://api.photobucket.com/oembed',                         false ),
+                       'http://gi*.photobucket.com/groups/*'                 => array( 'http://api.photobucket.com/oembed',                         false ),
+                       '#https?://(www\.)?scribd\.com/doc/.*#i'              => array( 'http://www.scribd.com/services/oembed',                     true  ),
+                       '#https?://wordpress.tv/.*#i'                         => array( 'http://wordpress.tv/oembed/',                               true  ),
+                       '#https?://(.+\.)?polldaddy\.com/.*#i'                => array( 'https://polldaddy.com/oembed/',                             true  ),
+                       '#https?://poll\.fm/.*#i'                             => array( 'https://polldaddy.com/oembed/',                             true  ),
+                       '#https?://(www\.)?funnyordie\.com/videos/.*#i'       => array( 'http://www.funnyordie.com/oembed',                          true  ),
+                       '#https?://(www\.)?twitter\.com/.+?/status(es)?/.*#i' => array( 'https://publish.twitter.com/oembed',                        true  ),
+                       '#https?://(www\.)?twitter\.com/.+?/timelines/.*#i'   => array( 'https://publish.twitter.com/oembed',                        true  ),
+                       '#https?://(www\.)?twitter\.com/i/moments/.*#i'       => array( 'https://publish.twitter.com/oembed',                        true  ),
+                       '#https?://vine.co/v/.*#i'                            => array( 'https://vine.co/oembed.{format}',                           true  ),
+                       '#https?://(www\.)?soundcloud\.com/.*#i'              => array( 'http://soundcloud.com/oembed',                              true  ),
+                       '#https?://(.+?\.)?slideshare\.net/.*#i'              => array( 'https://www.slideshare.net/api/oembed/2',                   true  ),
+                       '#https?://(www\.)?instagr(\.am|am\.com)/p/.*#i'      => array( 'https://api.instagram.com/oembed',                          true  ),
+                       '#https?://(open|play)\.spotify\.com/.*#i'            => array( 'https://embed.spotify.com/oembed/',                         true  ),
+                       '#https?://(.+\.)?imgur\.com/.*#i'                    => array( 'http://api.imgur.com/oembed',                               true  ),
+                       '#https?://(www\.)?meetu(\.ps|p\.com)/.*#i'           => array( 'http://api.meetup.com/oembed',                              true  ),
+                       '#https?://(www\.)?issuu\.com/.+/docs/.+#i'           => array( 'http://issuu.com/oembed_wp',                                true  ),
+                       '#https?://(www\.)?collegehumor\.com/video/.*#i'      => array( 'http://www.collegehumor.com/oembed.{format}',               true  ),
+                       '#https?://(www\.)?mixcloud\.com/.*#i'                => array( 'http://www.mixcloud.com/oembed',                            true  ),
+                       '#https?://(www\.|embed\.)?ted\.com/talks/.*#i'       => array( 'http://www.ted.com/talks/oembed.{format}',                  true  ),
+                       '#https?://(www\.)?(animoto|video214)\.com/play/.*#i' => array( 'https://animoto.com/oembeds/create',                        true  ),
+                       '#https?://(.+)\.tumblr\.com/post/.*#i'               => array( 'https://www.tumblr.com/oembed/1.0',                         true  ),
+                       '#https?://(www\.)?kickstarter\.com/projects/.*#i'    => array( 'https://www.kickstarter.com/services/oembed',               true  ),
+                       '#https?://kck\.st/.*#i'                              => array( 'https://www.kickstarter.com/services/oembed',               true  ),
+                       '#https?://cloudup\.com/.*#i'                         => array( 'https://cloudup.com/oembed',                                true  ),
+                       '#https?://(www\.)?reverbnation\.com/.*#i'            => array( 'https://www.reverbnation.com/oembed',                       true  ),
+                       '#https?://videopress.com/v/.*#'                      => array( 'https://public-api.wordpress.com/oembed/1.0/?for=' . $host, true  ),
+                       '#https?://(www\.)?reddit\.com/r/[^/]+/comments/.*#i' => array( 'https://www.reddit.com/oembed',                             true  ),
+                       '#https?://(www\.)?speakerdeck\.com/.*#i'             => array( 'https://speakerdeck.com/oembed.{format}',                   true  ),
                );
 
                if ( ! empty( self::$early_providers['add'] ) ) {
@@ -82,70 +115,69 @@ class WP_oEmbed {
                self::$early_providers = array();
 
                /**
-                * Filter the list of oEmbed providers.
+                * Filters the list of whitelisted oEmbed providers.
                 *
-                * Discovery is disabled for users lacking the unfiltered_html capability.
-                * Only providers in this array will be used for those users.
+                * Since WordPress 4.4, oEmbed discovery is enabled for all users and allows embedding of sanitized
+                * iframes. The providers in this list are whitelisted, meaning they are trusted and allowed to
+                * embed any content, such as iframes, videos, JavaScript, and arbitrary HTML.
                 *
                 * Supported providers:
                 *
-                * | ------------ | -------------------- | ----- | --------- |
-                * |   Provider   |        Flavor        |  SSL  |   Since   |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Blip         | blip.tv              |       | 2.9.0     |
-                * | Dailymotion  | dailymotion.com      |  Yes  | 2.9.0     |
-                * | Flickr       | flickr.com           |  Yes  | 2.9.0     |
-                * | Hulu         | hulu.com             |  Yes  | 2.9.0     |
-                * | Photobucket  | photobucket.com      |       | 2.9.0     |
-                * | Revision3    | revision3.com        |       | 2.9.0     |
-                * | Scribd       | scribd.com           |  Yes  | 2.9.0     |
-                * | Vimeo        | vimeo.com            |  Yes  | 2.9.0     |
-                * | WordPress.tv | wordpress.tv         |  Yes  | 2.9.0     |
-                * | YouTube      | youtube.com/watch    |  Yes  | 2.9.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Funny or Die | funnyordie.com       |  Yes  | 3.0.0     |
-                * | Polldaddy    | polldaddy.com        |  Yes  | 3.0.0     |
-                * | SmugMug      | smugmug.com          |  Yes  | 3.0.0     |
-                * | YouTube      | youtu.be             |  Yes  | 3.0.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Twitter      | twitter.com          |  Yes  | 3.4.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Instagram    | instagram.com        |       | 3.5.0     |
-                * | Instagram    | instagr.am           |       | 3.5.0     |
-                * | Slideshare   | slideshare.net       |  Yes  | 3.5.0     |
-                * | SoundCloud   | soundcloud.com       |  Yes  | 3.5.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Dailymotion  | dai.ly               |       | 3.6.0     |
-                * | Flickr       | flic.kr              |  Yes  | 3.6.0     |
-                * | Rdio         | rdio.com             |  Yes  | 3.6.0     |
-                * | Rdio         | rd.io                |  Yes  | 3.6.0     |
-                * | Spotify      | spotify.com          |  Yes  | 3.6.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Imgur        | imgur.com            |  Yes  | 3.9.0     |
-                * | Meetup.com   | meetup.com           |  Yes  | 3.9.0     |
-                * | Meetup.com   | meetu.ps             |  Yes  | 3.9.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Animoto      | animoto.com          |  Yes  | 4.0.0     |
-                * | Animoto      | video214.com         |  Yes  | 4.0.0     |
-                * | CollegeHumor | collegehumor.com     |  Yes  | 4.0.0     |
-                * | Issuu        | issuu.com            |  Yes  | 4.0.0     |
-                * | Mixcloud     | mixcloud.com         |  Yes  | 4.0.0     |
-                * | Polldaddy    | poll.fm              |  Yes  | 4.0.0     |
-                * | TED          | ted.com              |  Yes  | 4.0.0     |
-                * | YouTube      | youtube.com/playlist |  Yes  | 4.0.0     |
-                * | ------------ | -------------------- | ----- | --------- |
-                * | Vine         | vine.co              |  Yes  | 4.1.0     |
-                * | ------------ | -------------------- | ----- | --------- |
+                * |   Provider   |        Flavor         | Supports HTTPS |   Since   |
+                * | ------------ | --------------------- | :------------: | --------- |
+                * | Dailymotion  | dailymotion.com       |      Yes       | 2.9.0     |
+                * | Flickr       | flickr.com            |      Yes       | 2.9.0     |
+                * | Hulu         | hulu.com              |      Yes       | 2.9.0     |
+                * | Photobucket  | photobucket.com       |      No        | 2.9.0     |
+                * | Scribd       | scribd.com            |      Yes       | 2.9.0     |
+                * | Vimeo        | vimeo.com             |      Yes       | 2.9.0     |
+                * | WordPress.tv | wordpress.tv          |      Yes       | 2.9.0     |
+                * | YouTube      | youtube.com/watch     |      Yes       | 2.9.0     |
+                * | Funny or Die | funnyordie.com        |      Yes       | 3.0.0     |
+                * | Polldaddy    | polldaddy.com         |      Yes       | 3.0.0     |
+                * | SmugMug      | smugmug.com           |      Yes       | 3.0.0     |
+                * | YouTube      | youtu.be              |      Yes       | 3.0.0     |
+                * | Twitter      | twitter.com           |      Yes       | 3.4.0     |
+                * | Instagram    | instagram.com         |      Yes       | 3.5.0     |
+                * | Instagram    | instagr.am            |      Yes       | 3.5.0     |
+                * | Slideshare   | slideshare.net        |      Yes       | 3.5.0     |
+                * | SoundCloud   | soundcloud.com        |      Yes       | 3.5.0     |
+                * | Dailymotion  | dai.ly                |      Yes       | 3.6.0     |
+                * | Flickr       | flic.kr               |      Yes       | 3.6.0     |
+                * | Spotify      | spotify.com           |      Yes       | 3.6.0     |
+                * | Imgur        | imgur.com             |      Yes       | 3.9.0     |
+                * | Meetup.com   | meetup.com            |      Yes       | 3.9.0     |
+                * | Meetup.com   | meetu.ps              |      Yes       | 3.9.0     |
+                * | Animoto      | animoto.com           |      Yes       | 4.0.0     |
+                * | Animoto      | video214.com          |      Yes       | 4.0.0     |
+                * | CollegeHumor | collegehumor.com      |      Yes       | 4.0.0     |
+                * | Issuu        | issuu.com             |      Yes       | 4.0.0     |
+                * | Mixcloud     | mixcloud.com          |      Yes       | 4.0.0     |
+                * | Polldaddy    | poll.fm               |      Yes       | 4.0.0     |
+                * | TED          | ted.com               |      Yes       | 4.0.0     |
+                * | YouTube      | youtube.com/playlist  |      Yes       | 4.0.0     |
+                * | Vine         | vine.co               |      Yes       | 4.1.0     |
+                * | Tumblr       | tumblr.com            |      Yes       | 4.2.0     |
+                * | Kickstarter  | kickstarter.com       |      Yes       | 4.2.0     |
+                * | Kickstarter  | kck.st                |      Yes       | 4.2.0     |
+                * | Cloudup      | cloudup.com           |      Yes       | 4.4.0     |
+                * | ReverbNation | reverbnation.com      |      Yes       | 4.4.0     |
+                * | VideoPress   | videopress.com        |      Yes       | 4.4.0     |
+                * | Reddit       | reddit.com            |      Yes       | 4.4.0     |
+                * | Speaker Deck | speakerdeck.com       |      Yes       | 4.4.0     |
+                * | Twitter      | twitter.com/timelines |      Yes       | 4.5.0     |
+                * | Twitter      | twitter.com/moments   |      Yes       | 4.5.0     |
                 *
                 * No longer supported providers:
                 *
-                * | ------------ | -------------------- | ----- | --------- | --------- |
-                * |   Provider   |        Flavor        |  SSL  |   Since   |  Removed  |
-                * | ------------ | -------------------- | ----- | --------- | --------- |
-                * | Qik          | qik.com              |  Yes  | 2.9.0     | 3.9.0     |
-                * | ------------ | -------------------- | ----- | --------- | --------- |
-                * | Viddler      | viddler.com          |  Yes  | 2.9.0     | 4.0.0     |
-                * | ------------ | -------------------- | ----- | --------- | --------- |
+                * |   Provider   |        Flavor        | Supports HTTPS |   Since   |  Removed  |
+                * | ------------ | -------------------- | :------------: | --------- | --------- |
+                * | Qik          | qik.com              |      Yes       | 2.9.0     | 3.9.0     |
+                * | Viddler      | viddler.com          |      Yes       | 2.9.0     | 4.0.0     |
+                * | Revision3    | revision3.com        |      No        | 2.9.0     | 4.2.0     |
+                * | Blip         | blip.tv              |      No        | 2.9.0     | 4.4.0     |
+                * | Rdio         | rdio.com             |      Yes       | 3.6.0     | 4.4.1     |
+                * | Rdio         | rd.io                |      Yes       | 3.6.0     | 4.4.1     |
                 *
                 * @see wp_oembed_add_provider()
                 *
@@ -160,7 +192,7 @@ class WP_oEmbed {
        }
 
        /**
-        * Make private/protected methods readable for backwards compatibility.
+        * Exposes private/protected methods for backward compatibility.
         *
         * @since 4.0.0
         * @access public
@@ -170,7 +202,10 @@ class WP_oEmbed {
         * @return mixed|bool Return value of the callback, false otherwise.
         */
        public function __call( $name, $arguments ) {
-               return call_user_func_array( array( $this, $name ), $arguments );
+               if ( in_array( $name, $this->compat_methods ) ) {
+                       return call_user_func_array( array( $this, $name ), $arguments );
+               }
+               return false;
        }
 
        /**
@@ -183,9 +218,10 @@ class WP_oEmbed {
         *
         * @param string        $url  The URL to the content.
         * @param string|array  $args Optional provider arguments.
-        * @return bool|string False on failure, otherwise the oEmbed provider URL.
+        * @return false|string False on failure, otherwise the oEmbed provider URL.
         */
        public function get_provider( $url, $args = '' ) {
+               $args = wp_parse_args( $args );
 
                $provider = false;
 
@@ -214,14 +250,16 @@ class WP_oEmbed {
        }
 
        /**
-        * Add an oEmbed provider just-in-time when wp_oembed_add_provider() is called
-        * before the 'plugins_loaded' hook.
+        * Adds an oEmbed provider.
         *
-        * The just-in-time addition is for the benefit of the 'oembed_providers' filter.
+        * The provider is removed just-in-time when wp_oembed_add_provider() is called before
+        * the {@see 'plugins_loaded'} hook.
         *
+        * The just-in-time addition is for the benefit of the {@see 'oembed_providers'} filter.
+        *
+        * @static
         * @since 4.0.0
         * @access public
-        * @static
         *
         * @see wp_oembed_add_provider()
         *
@@ -240,10 +278,12 @@ class WP_oEmbed {
        }
 
        /**
-        * Remove an oEmbed provider just-in-time when wp_oembed_remove_provider() is called
-        * before the 'plugins_loaded' hook.
+        * Removes an oEmbed provider.
+        *
+        * The provider is removed just-in-time when wp_oembed_remove_provider() is called before
+        * the {@see 'plugins_loaded'} hook.
         *
-        * The just-in-time removal is for the benefit of the 'oembed_providers' filter.
+        * The just-in-time removal is for the benefit of the {@see 'oembed_providers'} filter.
         *
         * @since 4.0.0
         * @access public
@@ -268,18 +308,45 @@ class WP_oEmbed {
         * @see WP_oEmbed::fetch()
         * @see WP_oEmbed::data2html()
         *
-        * @param string $url The URL to the content that should be attempted to be embedded.
-        * @param array $args Optional arguments. Usually passed from a shortcode.
+        * @since 2.9.0
+        * @access public
+        *
+        * @param string       $url  The URL to the content that should be attempted to be embedded.
+        * @param array|string $args Optional. Arguments, usually passed from a shortcode. Default empty.
         * @return false|string False on failure, otherwise the UNSANITIZED (and potentially unsafe) HTML that should be used to embed.
         */
-       function get_html( $url, $args = '' ) {
+       public function get_html( $url, $args = '' ) {
+               $args = wp_parse_args( $args );
+
+               /**
+                * Filters the oEmbed result before any HTTP requests are made.
+                *
+                * This allows one to short-circuit the default logic, perhaps by
+                * replacing it with a routine that is more optimal for your setup.
+                *
+                * Passing a non-null value to the filter will effectively short-circuit retrieval,
+                * returning the passed value instead.
+                *
+                * @since 4.5.3
+                *
+                * @param null|string $result The UNSANITIZED (and potentially unsafe) HTML that should be used to embed. Default null.
+                * @param string      $url    The URL to the content that should be attempted to be embedded.
+                * @param array       $args   Optional. Arguments, usually passed from a shortcode. Default empty.
+                */
+               $pre = apply_filters( 'pre_oembed_result', null, $url, $args );
+
+               if ( null !== $pre ) {
+                       return $pre;
+               }
+
                $provider = $this->get_provider( $url, $args );
 
-               if ( !$provider || false === $data = $this->fetch( $provider, $url, $args ) )
+               if ( ! $provider || false === $data = $this->fetch( $provider, $url, $args ) ) {
                        return false;
+               }
 
                /**
-                * Filter the HTML returned by the oEmbed provider.
+                * Filters the HTML returned by the oEmbed provider.
                 *
                 * @since 2.9.0
                 *
@@ -293,14 +360,20 @@ class WP_oEmbed {
        /**
         * Attempts to discover link tags at the given URL for an oEmbed provider.
         *
+        * @since 2.9.0
+        * @access public
+        *
         * @param string $url The URL that should be inspected for discovery `<link>` tags.
-        * @return bool|string False on failure, otherwise the oEmbed provider URL.
+        * @return false|string False on failure, otherwise the oEmbed provider URL.
         */
        public function discover( $url ) {
                $providers = array();
+               $args = array(
+                       'limit_response_size' => 153600, // 150 KB
+               );
 
                /**
-                * Filter oEmbed remote get arguments.
+                * Filters oEmbed remote get arguments.
                 *
                 * @since 4.0.0
                 *
@@ -309,14 +382,14 @@ class WP_oEmbed {
                 * @param array  $args oEmbed remote get arguments.
                 * @param string $url  URL to be inspected.
                 */
-               $args = apply_filters( 'oembed_remote_get_args', array(), $url );
+               $args = apply_filters( 'oembed_remote_get_args', $args, $url );
 
                // Fetch URL content
                $request = wp_safe_remote_get( $url, $args );
                if ( $html = wp_remote_retrieve_body( $request ) ) {
 
                        /**
-                        * Filter the link types that contain oEmbed provider URLs.
+                        * Filters the link types that contain oEmbed provider URLs.
                         *
                         * @since 2.9.0
                         *
@@ -331,7 +404,9 @@ class WP_oEmbed {
                        ) );
 
                        // Strip <body>
-                       $html = substr( $html, 0, stripos( $html, '</head>' ) );
+                       if ( $html_head_end = stripos( $html, '</head>' ) ) {
+                               $html = substr( $html, 0, $html_head_end );
+                       }
 
                        // Do a quick check
                        $tagfound = false;
@@ -342,12 +417,12 @@ class WP_oEmbed {
                                }
                        }
 
-                       if ( $tagfound && preg_match_all( '/<link([^<>]+)>/i', $html, $links ) ) {
+                       if ( $tagfound && preg_match_all( '#<link([^<>]+)/?>#iU', $html, $links ) ) {
                                foreach ( $links[1] as $link ) {
                                        $atts = shortcode_parse_atts( $link );
 
                                        if ( !empty($atts['type']) && !empty($linktypes[$atts['type']]) && !empty($atts['href']) ) {
-                                               $providers[$linktypes[$atts['type']]] = $atts['href'];
+                                               $providers[$linktypes[$atts['type']]] = htmlspecialchars_decode( $atts['href'] );
 
                                                // Stop here if it's JSON (that's all we need)
                                                if ( 'json' == $linktypes[$atts['type']] )
@@ -369,10 +444,13 @@ class WP_oEmbed {
        /**
         * Connects to a oEmbed provider and returns the result.
         *
-        * @param string $provider The URL to the oEmbed provider.
-        * @param string $url The URL to the content that is desired to be embedded.
-        * @param array $args Optional arguments. Usually passed from a shortcode.
-        * @return bool|object False on failure, otherwise the result in the form of an object.
+        * @since 2.9.0
+        * @access public
+        *
+        * @param string       $provider The URL to the oEmbed provider.
+        * @param string       $url      The URL to the content that is desired to be embedded.
+        * @param array|string $args     Optional. Arguments, usually passed from a shortcode. Default empty.
+        * @return false|object False on failure, otherwise the result in the form of an object.
         */
        public function fetch( $provider, $url, $args = '' ) {
                $args = wp_parse_args( $args, wp_embed_defaults( $url ) );
@@ -382,7 +460,7 @@ class WP_oEmbed {
                $provider = add_query_arg( 'url', urlencode($url), $provider );
 
                /**
-                * Filter the oEmbed URL to be fetched.
+                * Filters the oEmbed URL to be fetched.
                 *
                 * @since 2.9.0
                 *
@@ -392,7 +470,7 @@ class WP_oEmbed {
                 */
                $provider = apply_filters( 'oembed_fetch_url', $provider, $url, $args );
 
-               foreach( array( 'json', 'xml' ) as $format ) {
+               foreach ( array( 'json', 'xml' ) as $format ) {
                        $result = $this->_fetch_with_format( $provider, $format );
                        if ( is_wp_error( $result ) && 'not-implemented' == $result->get_error_code() )
                                continue;
@@ -406,9 +484,10 @@ class WP_oEmbed {
         *
         * @since 3.0.0
         * @access private
+        *
         * @param string $provider_url_with_args URL to the provider with full arguments list (url, maxheight, etc.)
         * @param string $format Format to use
-        * @return bool|object False on failure, otherwise the result in the form of an object.
+        * @return false|object|WP_Error False on failure, otherwise the result in the form of an object.
         */
        private function _fetch_with_format( $provider_url_with_args, $format ) {
                $provider_url_with_args = add_query_arg( 'format', $format, $provider_url_with_args );
@@ -430,9 +509,13 @@ class WP_oEmbed {
         *
         * @since 3.0.0
         * @access private
+        *
+        * @param string $response_body
+        * @return object|false
         */
        private function _parse_json( $response_body ) {
-               return ( ( $data = json_decode( trim( $response_body ) ) ) && is_object( $data ) ) ? $data : false;
+               $data = json_decode( trim( $response_body ) );
+               return ( $data && is_object( $data ) ) ? $data : false;
        }
 
        /**
@@ -440,6 +523,9 @@ class WP_oEmbed {
         *
         * @since 3.0.0
         * @access private
+        *
+        * @param string $response_body
+        * @return object|false
         */
        private function _parse_xml( $response_body ) {
                if ( ! function_exists( 'libxml_disable_entity_loader' ) )
@@ -457,13 +543,16 @@ class WP_oEmbed {
        }
 
        /**
-        * Helper function for parsing an XML response body.
+        * Serves as a helper function for parsing an XML response body.
         *
         * @since 3.6.0
         * @access private
+        *
+        * @param string $response_body
+        * @return object|false
         */
        private function _parse_xml_body( $response_body ) {
-               if ( ! function_exists( 'simplexml_import_dom' ) || ! class_exists( 'DOMDocument' ) )
+               if ( ! function_exists( 'simplexml_import_dom' ) || ! class_exists( 'DOMDocument', false ) )
                        return false;
 
                $dom = new DOMDocument;
@@ -492,7 +581,10 @@ class WP_oEmbed {
        }
 
        /**
-        * Converts a data object from {@link WP_oEmbed::fetch()} and returns the HTML.
+        * Converts a data object from WP_oEmbed::fetch() and returns the HTML.
+        *
+        * @since 2.9.0
+        * @access public
         *
         * @param object $data A data object result from an oEmbed provider.
         * @param string $url The URL to the content that is desired to be embedded.
@@ -531,7 +623,7 @@ class WP_oEmbed {
                }
 
                /**
-                * Filter the returned oEmbed HTML.
+                * Filters the returned oEmbed HTML.
                 *
                 * Use this filter to add support for custom data types, or to filter the result.
                 *
@@ -545,37 +637,62 @@ class WP_oEmbed {
        }
 
        /**
-        * Strip any new lines from the HTML.
+        * Strips any new lines from the HTML.
         *
+        * @since 2.9.0 as strip_scribd_newlines()
+        * @since 3.0.0
         * @access public
+        *
         * @param string $html Existing HTML.
         * @param object $data Data object from WP_oEmbed::data2html()
         * @param string $url The original URL passed to oEmbed.
         * @return string Possibly modified $html
         */
        public function _strip_newlines( $html, $data, $url ) {
-               if ( false !== strpos( $html, "\n" ) )
-                       $html = str_replace( array( "\r\n", "\n" ), '', $html );
+               if ( false === strpos( $html, "\n" ) ) {
+                       return $html;
+               }
+
+               $count = 1;
+               $found = array();
+               $token = '__PRE__';
+               $search = array( "\t", "\n", "\r", ' ' );
+               $replace = array( '__TAB__', '__NL__', '__CR__', '__SPACE__' );
+               $tokenized = str_replace( $search, $replace, $html );
+
+               preg_match_all( '#(<pre[^>]*>.+?</pre>)#i', $tokenized, $matches, PREG_SET_ORDER );
+               foreach ( $matches as $i => $match ) {
+                       $tag_html = str_replace( $replace, $search, $match[0] );
+                       $tag_token = $token . $i;
+
+                       $found[ $tag_token ] = $tag_html;
+                       $html = str_replace( $tag_html, $tag_token, $html, $count );
+               }
+
+               $replaced = str_replace( $replace, $search, $html );
+               $stripped = str_replace( array( "\r\n", "\n" ), '', $replaced );
+               $pre = array_values( $found );
+               $tokens = array_keys( $found );
 
-               return $html;
+               return str_replace( $tokens, $pre, $stripped );
        }
 }
 
 /**
- * Returns the initialized {@link WP_oEmbed} object
+ * Returns the initialized WP_oEmbed object.
  *
  * @since 2.9.0
  * @access private
  *
- * @see WP_oEmbed
+ * @staticvar WP_oEmbed $wp_oembed
  *
  * @return WP_oEmbed object.
  */
 function _wp_oembed_get_object() {
-       static $wp_oembed;
+       static $wp_oembed = null;
 
-       if ( is_null($wp_oembed) )
+       if ( is_null( $wp_oembed ) ) {
                $wp_oembed = new WP_oEmbed();
-
+       }
        return $wp_oembed;
 }