WordPress/wp-includes/class-oembed.php

237 lines
7.2 KiB
PHP

<?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.
*
* @link http://codex.wordpress.org/oEmbed oEmbed Codex Article
* @link http://oembed.com/ oEmbed Homepage
*
* @package WordPress
* @subpackage oEmbed
*/
/**
* oEmbed class.
*
* @package WordPress
* @subpackage oEmbed
* @since 2.9.0
*/
class WP_oEmbed {
var $providers = array();
/**
* PHP4 constructor
*/
function WP_oEmbed() {
return $this->__construct();
}
/**
* PHP5 constructor
*
* @uses apply_filters() Filters a list of pre-defined oEmbed providers.
*/
function __construct() {
// List out some popular sites, mainly ones that don't have discovery tags in their <head>
// The WP_Embed class disables discovery for non-unfiltered_html users,
// so only providers in this array will be used for them.
$this->providers = apply_filters( 'oembed_providers', array(
'http://blip.tv/file/*' => 'http://blip.tv/oembed/',
'http://*.flickr.com/*' => 'http://www.flickr.com/services/oembed/',
'http://*.viddler.com/*' => 'http://lab.viddler.com/services/oembed/',
'http://qik.com/*' => 'http://qik.com/api/oembed.{format}',
'http://*.revision3.com/*' => 'http://revision3.com/api/oembed/',
'http://www.hulu.com/watch/*' => 'http://www.hulu.com/api/oembed.{format}',
// Vimeo uses the discovery <link>, so leave this commented to use it as a discovery test
//'http://www.vimeo.com/*' => 'http://www.vimeo.com/api/oembed.{format}',
) );
}
/**
* The do-it-all function that takes a URL and attempts to return the HTML.
*
* @see WP_oEmbed::discover()
* @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.
* @return bool|string False on failure, otherwise the UNSANITIZED (and potentially unsafe) HTML that should be used to embed.
*/
function get_html( $url, $args = '' ) {
$provider = false;
if ( !isset($args['discover']) )
$args['discover'] = true;
foreach ( $this->providers as $matchmask => $providerurl ) {
// Turn the asterisk-type provider URLs into regex
$regex = '#' . str_replace( '___wildcard___', '(.+)', preg_quote( str_replace( '*', '___wildcard___', $matchmask ), '#' ) ) . '#i';
if ( preg_match( $regex, $url ) ) {
$provider = str_replace( '{format}', 'json', $providerurl ); // JSON is easier to deal with than XML
break;
}
}
if ( !$provider && $args['discover'] )
$provider = $this->discover( $url );
if ( !$provider || false === $data = $this->fetch( $provider, $url, $args ) )
return false;
return apply_filters( 'oembed_output', $this->data2html( $data, $url ), $url, $args );
}
/**
* Attempts to find oEmbed provider discovery <link> tags at the given URL.
*
* @param string $url The URL that should be inspected for discovery <link> tags.
* @return bool|string False on failure, otherwise the oEmbed provider URL.
*/
function discover( $url ) {
$providers = array();
// Fetch URL content
if ( $html = wp_remote_retrieve_body( wp_remote_get( $url ) ) ) {
// <link> types that contain oEmbed provider URLs
$linktypes = apply_filters( 'oembed_linktypes', array(
'application/json+oembed' => 'json',
'text/xml+oembed' => 'xml',
'application/xml+oembed' => 'xml', // Incorrect, but used by at least Vimeo
) );
// Strip <body>
$html = substr( $html, 0, stripos( $html, '</head>' ) );
// Do a quick check
$tagfound = false;
foreach ( $linktypes as $linktype => $format ) {
if ( stripos($html, $linktype) ) {
$tagfound = true;
break;
}
}
if ( $tagfound && preg_match_all( '/<link([^<>]+)>/i', $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'];
// Stop here if it's JSON (that's all we need)
if ( 'json' == $linktypes[$atts['type']] )
break;
}
}
}
}
// JSON is preferred to XML
if ( !empty($providers['json']) )
return $providers['json'];
elseif ( !empty($providers['xml']) )
return $providers['xml'];
else
return false;
}
/**
* 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.
*/
function fetch( $provider, $url, $args = '' ) {
$args = wp_parse_args( $args, wp_embed_defaults() );
$provider = add_query_arg( 'format', 'json', $provider ); // JSON is easier to deal with than XML
$provider = add_query_arg( 'maxwidth', $args['width'], $provider );
$provider = add_query_arg( 'maxheight', $args['height'], $provider );
$provider = add_query_arg( 'url', urlencode($url), $provider );
if ( !$result = wp_remote_retrieve_body( wp_remote_get( $provider ) ) )
return false;
$result = trim( $result );
// JSON?
// Example content: http://vimeo.com/api/oembed.json?url=http%3A%2F%2Fvimeo.com%2F240975
if ( $data = json_decode($result) ) {
return $data;
}
// Must be XML. Only parse it if PHP5 is installed. (PHP4 isn't worth the trouble.)
// Example content: http://vimeo.com/api/oembed.xml?url=http%3A%2F%2Fvimeo.com%2F240975
elseif ( function_exists('simplexml_load_string') ) {
$errors = libxml_use_internal_errors( 'true' );
$data = simplexml_load_string( $result );
libxml_use_internal_errors( $errors );
if ( is_object($data) )
return $data;
}
return false;
}
/**
* Converts a data object from {@link WP_oEmbed::fetch()} and returns the HTML.
*
* @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.
* @return bool|string False on error, otherwise the HTML needed to embed.
*/
function data2html( $data, $url ) {
if ( !is_object($data) || empty($data->type) )
return false;
switch ( $data->type ) {
case 'photo':
if ( empty($data->url) || empty($data->width) || empty($data->height) )
return false;
$title = ( !empty($data->title) ) ? $data->title : '';
return '<img src="' . esc_attr( clean_url( $data->url ) ) . '" alt="' . esc_attr($title) . '" width="' . esc_attr($data->width) . '" height="' . esc_attr($data->height) . '" />';
case 'video':
case 'rich':
return ( !empty($data->html) ) ? $data->html : false;
case 'link':
return ( !empty($data->title) ) ? '<a href="' . clean_url($url) . '">' . esc_html($data->title) . '</a>' : false;
}
return false;
}
}
/**
* Returns the initialized {@link WP_oEmbed} object
*
* @since 2.9.0
* @access private
*
* @see WP_oEmbed
* @uses WP_oEmbed
*
* @return WP_oEmbed object.
*/
function &_wp_oembed_get_object() {
static $wp_oembed;
if ( is_null($wp_oembed) )
$wp_oembed = new WP_oEmbed();
return $wp_oembed;
}