www.gusucode.com > wordpress PHP博客系统英文版 v4.5.1PHP源码程序 > wordpress PHP博客系统英文版 v4.5.1/wordpress/wordpress/wp-includes/class-wp-embed.php
<?php
/**
* API for easily embedding rich media such as videos and images into content.
*
* @package WordPress
* @subpackage Embed
* @since 2.9.0
*/
class WP_Embed {
public $handlers = array();
public $post_ID;
public $usecache = true;
public $linkifunknown = true;
public $last_attr = array();
public $last_url = '';
/**
* When a URL cannot be embedded, return false instead of returning a link
* or the URL. Bypasses the 'embed_maybe_make_link' filter.
*/
public $return_false_on_fail = false;
/**
* Constructor
*/
public function __construct() {
// Hack to get the [embed] shortcode to run before wpautop()
add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
// Shortcode placeholder for strip_shortcodes()
add_shortcode( 'embed', '__return_false' );
// Attempts to embed all URLs in a post
add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
// After a post is saved, cache oEmbed items via AJAX
add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );
add_action( 'edit_page_form', array( $this, 'maybe_run_ajax_cache' ) );
}
/**
* Process the [embed] shortcode.
*
* Since the [embed] shortcode needs to be run earlier than other shortcodes,
* this function removes all existing shortcodes, registers the [embed] shortcode,
* calls {@link do_shortcode()}, and then re-registers the old shortcodes.
*
* @global array $shortcode_tags
*
* @param string $content Content to parse
* @return string Content with shortcode parsed
*/
public function run_shortcode( $content ) {
global $shortcode_tags;
// Back up current registered shortcodes and clear them all out
$orig_shortcode_tags = $shortcode_tags;
remove_all_shortcodes();
add_shortcode( 'embed', array( $this, 'shortcode' ) );
// Do the shortcode (only the [embed] one is registered)
$content = do_shortcode( $content, true );
// Put the original shortcodes back
$shortcode_tags = $orig_shortcode_tags;
return $content;
}
/**
* If a post/page was saved, then output JavaScript to make
* an AJAX request that will call WP_Embed::cache_oembed().
*/
public function maybe_run_ajax_cache() {
$post = get_post();
if ( ! $post || empty( $_GET['message'] ) )
return;
?>
<script type="text/javascript">
jQuery(document).ready(function($){
$.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post->ID, 'relative' ); ?>");
});
</script>
<?php
}
/**
* Register an embed handler. Do not use this function directly, use {@link wp_embed_register_handler()} instead.
* This function should probably also only be used for sites that do not support oEmbed.
*
* @param string $id An internal ID/name for the handler. Needs to be unique.
* @param string $regex The regex that will be used to see if this handler should be used for a URL.
* @param callable $callback The callback function that will be called if the regex is matched.
* @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.
*/
public function register_handler( $id, $regex, $callback, $priority = 10 ) {
$this->handlers[$priority][$id] = array(
'regex' => $regex,
'callback' => $callback,
);
}
/**
* Unregister a previously registered embed handler. Do not use this function directly, use {@link wp_embed_unregister_handler()} instead.
*
* @param string $id The handler ID that should be removed.
* @param int $priority Optional. The priority of the handler to be removed (default: 10).
*/
public function unregister_handler( $id, $priority = 10 ) {
unset( $this->handlers[ $priority ][ $id ] );
}
/**
* The {@link do_shortcode()} callback function.
*
* Attempts to convert a URL into embed HTML. Starts by checking the URL against the regex of the registered embed handlers.
* If none of the regex matches and it's enabled, then the URL will be given to the {@link WP_oEmbed} class.
*
* @param array $attr {
* Shortcode attributes. Optional.
*
* @type int $width Width of the embed in pixels.
* @type int $height Height of the embed in pixels.
* }
* @param string $url The URL attempting to be embedded.
* @return string|false The embed HTML on success, otherwise the original URL.
* `->maybe_make_link()` can return false on failure.
*/
public function shortcode( $attr, $url = '' ) {
$post = get_post();
if ( empty( $url ) && ! empty( $attr['src'] ) ) {
$url = $attr['src'];
}
$this->last_url = $url;
if ( empty( $url ) ) {
$this->last_attr = $attr;
return '';
}
$rawattr = $attr;
$attr = wp_parse_args( $attr, wp_embed_defaults( $url ) );
$this->last_attr = $attr;
// kses converts & into & and we need to undo this
// See https://core.trac.wordpress.org/ticket/11311
$url = str_replace( '&', '&', $url );
// Look for known internal handlers
ksort( $this->handlers );
foreach ( $this->handlers as $priority => $handlers ) {
foreach ( $handlers as $id => $handler ) {
if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
if ( false !== $return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr ) )
/**
* Filter the returned embed handler.
*
* @since 2.9.0
*
* @see WP_Embed::shortcode()
*
* @param mixed $return The shortcode callback function to call.
* @param string $url The attempted embed URL.
* @param array $attr An array of shortcode attributes.
*/
return apply_filters( 'embed_handler_html', $return, $url, $attr );
}
}
}
$post_ID = ( ! empty( $post->ID ) ) ? $post->ID : null;
if ( ! empty( $this->post_ID ) ) // Potentially set by WP_Embed::cache_oembed()
$post_ID = $this->post_ID;
// Unknown URL format. Let oEmbed have a go.
if ( $post_ID ) {
// Check for a cached result (stored in the post meta)
$key_suffix = md5( $url . serialize( $attr ) );
$cachekey = '_oembed_' . $key_suffix;
$cachekey_time = '_oembed_time_' . $key_suffix;
/**
* Filter the oEmbed TTL value (time to live).
*
* @since 4.0.0
*
* @param int $time Time to live (in seconds).
* @param string $url The attempted embed URL.
* @param array $attr An array of shortcode attributes.
* @param int $post_ID Post ID.
*/
$ttl = apply_filters( 'oembed_ttl', DAY_IN_SECONDS, $url, $attr, $post_ID );
$cache = get_post_meta( $post_ID, $cachekey, true );
$cache_time = get_post_meta( $post_ID, $cachekey_time, true );
if ( ! $cache_time ) {
$cache_time = 0;
}
$cached_recently = ( time() - $cache_time ) < $ttl;
if ( $this->usecache || $cached_recently ) {
// Failures are cached. Serve one if we're using the cache.
if ( '{{unknown}}' === $cache )
return $this->maybe_make_link( $url );
if ( ! empty( $cache ) ) {
/**
* Filter the cached oEmbed HTML.
*
* @since 2.9.0
*
* @see WP_Embed::shortcode()
*
* @param mixed $cache The cached HTML result, stored in post meta.
* @param string $url The attempted embed URL.
* @param array $attr An array of shortcode attributes.
* @param int $post_ID Post ID.
*/
return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_ID );
}
}
/**
* Filter whether to inspect the given URL for discoverable link tags.
*
* @since 2.9.0
* @since 4.4.0 The default value changed to true.
*
* @see WP_oEmbed::discover()
*
* @param bool $enable Whether to enable `<link>` tag discovery. Default true.
*/
$attr['discover'] = ( apply_filters( 'embed_oembed_discover', true ) );
// Use oEmbed to get the HTML
$html = wp_oembed_get( $url, $attr );
// Maybe cache the result
if ( $html ) {
update_post_meta( $post_ID, $cachekey, $html );
update_post_meta( $post_ID, $cachekey_time, time() );
} elseif ( ! $cache ) {
update_post_meta( $post_ID, $cachekey, '{{unknown}}' );
}
// If there was a result, return it
if ( $html ) {
/** This filter is documented in wp-includes/class-wp-embed.php */
return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_ID );
}
}
// Still unknown
return $this->maybe_make_link( $url );
}
/**
* Delete all oEmbed caches. Unused by core as of 4.0.0.
*
* @param int $post_ID Post ID to delete the caches for.
*/
public function delete_oembed_caches( $post_ID ) {
$post_metas = get_post_custom_keys( $post_ID );
if ( empty($post_metas) )
return;
foreach ( $post_metas as $post_meta_key ) {
if ( '_oembed_' == substr( $post_meta_key, 0, 8 ) )
delete_post_meta( $post_ID, $post_meta_key );
}
}
/**
* Triggers a caching of all oEmbed results.
*
* @param int $post_ID Post ID to do the caching for.
*/
public function cache_oembed( $post_ID ) {
$post = get_post( $post_ID );
$post_types = get_post_types( array( 'show_ui' => true ) );
/**
* Filter the array of post types to cache oEmbed results for.
*
* @since 2.9.0
*
* @param array $post_types Array of post types to cache oEmbed results for. Defaults to post types with `show_ui` set to true.
*/
if ( empty( $post->ID ) || ! in_array( $post->post_type, apply_filters( 'embed_cache_oembed_types', $post_types ) ) ){
return;
}
// Trigger a caching
if ( ! empty( $post->post_content ) ) {
$this->post_ID = $post->ID;
$this->usecache = false;
$content = $this->run_shortcode( $post->post_content );
$this->autoembed( $content );
$this->usecache = true;
}
}
/**
* Passes any unlinked URLs that are on their own line to {@link WP_Embed::shortcode()} for potential embedding.
*
* @uses WP_Embed::autoembed_callback()
*
* @param string $content The content to be searched.
* @return string Potentially modified $content.
*/
public function autoembed( $content ) {
// Replace line breaks from all HTML elements with placeholders.
$content = wp_replace_in_html_tags( $content, array( "\n" => '<!-- wp-line-break -->' ) );
// Find URLs that are on their own line.
$content = preg_replace_callback( '|^(\s*)(https?://[^\s"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
// Put the line breaks back.
return str_replace( '<!-- wp-line-break -->', "\n", $content );
}
/**
* Callback function for {@link WP_Embed::autoembed()}.
*
* @param array $match A regex match array.
* @return string The embed HTML on success, otherwise the original URL.
*/
public function autoembed_callback( $match ) {
$oldval = $this->linkifunknown;
$this->linkifunknown = false;
$return = $this->shortcode( array(), $match[2] );
$this->linkifunknown = $oldval;
return $match[1] . $return . $match[3];
}
/**
* Conditionally makes a hyperlink based on an internal class variable.
*
* @param string $url URL to potentially be linked.
* @return false|string Linked URL or the original URL. False if 'return_false_on_fail' is true.
*/
public function maybe_make_link( $url ) {
if ( $this->return_false_on_fail ) {
return false;
}
$output = ( $this->linkifunknown ) ? '<a href="' . esc_url($url) . '">' . esc_html($url) . '</a>' : $url;
/**
* Filter the returned, maybe-linked embed URL.
*
* @since 2.9.0
*
* @param string $output The linked or original URL.
* @param string $url The original URL.
*/
return apply_filters( 'embed_maybe_make_link', $output, $url );
}
}
$GLOBALS['wp_embed'] = new WP_Embed();