WP_Embed::shortcode( array $attr, string $url = '' )
The do_shortcode() callback function.
Description
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 WP_oEmbed class.
Parameters
- $attr
-
(Required) Shortcode attributes. Optional.
- 'width'
(int) Width of the embed in pixels. - 'height'
(int) Height of the embed in pixels.
- 'width'
- $url
-
(Optional) The URL attempting to be embedded.
Default value: ''
Return
(string|false) The embed HTML on success, otherwise the original URL. ->maybe_make_link()
can return false on failure.
Source
File: wp-includes/class-wp-embed.php
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 ) )
/**
* Filters the returned embed handler.
*
* @since WP-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;
// Potentially set by WP_Embed::cache_oembed().
if ( ! empty( $this->post_ID ) ) {
$post_ID = $this->post_ID;
}
// Check for a cached result (stored as custom post or in the post meta).
$key_suffix = md5( $url . serialize( $attr ) );
$cachekey = '_oembed_' . $key_suffix;
$cachekey_time = '_oembed_time_' . $key_suffix;
/**
* Filters the oEmbed TTL value (time to live).
*
* @since WP-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 = '';
$cache_time = 0;
$cached_post_id = $this->find_oembed_post_id( $key_suffix );
if ( $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;
}
} elseif ( $cached_post_id ) {
$cached_post = get_post( $cached_post_id );
$cache = $cached_post->post_content;
$cache_time = strtotime( $cached_post->post_modified_gmt );
}
$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 ) ) {
/**
* Filters the cached oEmbed HTML.
*
* @since WP-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 );
}
}
/**
* Filters whether to inspect the given URL for discoverable link tags.
*
* @since WP-2.9.0
* @since WP-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 );
if ( $post_ID ) {
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}}' );
}
} else {
$has_kses = false !== has_filter( 'content_save_pre', 'wp_filter_post_kses' );
if ( $has_kses ) {
// Prevent KSES from corrupting JSON in post_content.
kses_remove_filters();
}
$insert_post_args = array(
'post_name' => $key_suffix,
'post_status' => 'publish',
'post_type' => 'oembed_cache',
);
if ( $html ) {
if ( $cached_post_id ) {
wp_update_post( wp_slash( array(
'ID' => $cached_post_id,
'post_content' => $html,
) ) );
} else {
wp_insert_post( wp_slash( array_merge(
$insert_post_args,
array(
'post_content' => $html,
)
) ) );
}
} elseif ( ! $cache ) {
wp_insert_post( wp_slash( array_merge(
$insert_post_args,
array(
'post_content' => '{{unknown}}',
)
) ) );
}
if ( $has_kses ) {
kses_init_filters();
}
}
// 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 );
}