Builds SimplePie object based on RSS or Atom feed from URL.
Parameters
$urlstring|string[]required- URL of feed to retrieve. If an array of URLs, the feeds are merged using SimplePie’s multifeed feature.
See also http://simplepie.org/wiki/faq/typical_multifeed_gotchas
Source
function fetch_feed( $url ) {
if ( ! class_exists( 'SimplePie\SimplePie', false ) ) {
require_once ABSPATH . WPINC . '/class-simplepie.php';
}
require_once ABSPATH . WPINC . '/class-wp-feed-cache-transient.php';
require_once ABSPATH . WPINC . '/class-wp-simplepie-file.php';
require_once ABSPATH . WPINC . '/class-wp-simplepie-sanitize-kses.php';
$feed = new SimplePie\SimplePie();
$feed->get_registry()->register( SimplePie\Sanitize::class, 'WP_SimplePie_Sanitize_KSES', true );
/*
* We must manually overwrite $feed->sanitize because SimplePie's constructor
* sets it before we have a chance to set the sanitization class.
*/
$feed->sanitize = new WP_SimplePie_Sanitize_KSES();
// Register the cache handler using the recommended method for SimplePie 1.3 or later.
if ( method_exists( 'SimplePie_Cache', 'register' ) ) {
SimplePie_Cache::register( 'wp_transient', 'WP_Feed_Cache_Transient' );
$feed->set_cache_location( 'wp_transient' );
} else {
// Back-compat for SimplePie 1.2.x.
require_once ABSPATH . WPINC . '/class-wp-feed-cache.php';
$feed->set_cache_class( 'WP_Feed_Cache' );
}
$feed->get_registry()->register( SimplePie\File::class, 'WP_SimplePie_File', true );
/** This filter is documented in wp-includes/class-wp-feed-cache-transient.php */
$feed->set_cache_duration( apply_filters( 'wp_feed_cache_transient_lifetime', 12 * HOUR_IN_SECONDS, $url ) );
/**
* Fires just before processing the SimplePie feed object.
*
* @since 3.0.0
*
* @param SimplePie\SimplePie $feed SimplePie feed object (passed by reference).
* @param string|string[] $url URL of feed or array of URLs of feeds to retrieve.
*/
do_action_ref_array( 'wp_feed_options', array( &$feed, $url ) );
if ( empty( $url ) ) {
/*
* @todo: Set $url to empty string once supported by SimplePie.
*
* The early return without proceeding is to work around a PHP 8.5
* deprecation issue resolved in https://github.com/simplepie/simplepie/pull/949
*
* To avoid the duplicate code, this block can be replaced with `$url = '';` once SimplePie
* is upgraded to a version that includes the fix.
*/
$feed->init();
$feed->set_output_encoding( get_bloginfo( 'charset' ) );
if ( $feed->error() ) {
return new WP_Error( 'simplepie-error', $feed->error() );
}
return $feed;
} elseif ( is_array( $url ) && count( $url ) === 1 ) {
$url = array_shift( $url );
} elseif ( is_array( $url ) ) {
$feeds = array();
$simplepie_errors = array();
foreach ( $url as $feed_url ) {
$simplepie_instance = clone $feed;
$simplepie_instance->set_feed_url( $feed_url );
$simplepie_instance->init();
$simplepie_instance->set_output_encoding( get_bloginfo( 'charset' ) );
if ( $simplepie_instance->error() ) {
$simplepie_errors[] = sprintf(
/* translators: %1$s is the feed URL, %2$s is the error message. */
__( 'Error fetching feed %1$s: %2$s' ),
esc_url( $feed_url ),
$simplepie_instance->error()
);
unset( $simplepie_instance );
continue;
}
$feeds[] = $simplepie_instance;
unset( $simplepie_instance );
}
if ( ! empty( $simplepie_errors ) ) {
return new WP_Error( 'simplepie-error', $simplepie_errors );
}
$feed->init();
$feed->data['items'] = SimplePie\SimplePie::merge_items( $feeds );
return $feed;
}
$feed->set_feed_url( $url );
$feed->init();
$feed->set_output_encoding( get_bloginfo( 'charset' ) );
if ( $feed->error() ) {
return new WP_Error( 'simplepie-error', $feed->error() );
}
return $feed;
}
Hooks
- apply_filters( ‘wp_feed_cache_transient_lifetime’,
int $lifetime ,string $name ) Filters the transient lifetime of the feed cache.
- do_action_ref_array( ‘wp_feed_options’,
SimplePieSimplePie $feed ,string|string[] $url ) Fires just before processing the SimplePie feed object.
Changelog
| Version | Description |
|---|---|
| 2.8.0 | Introduced. |
Example
This example will retrieve and display a list of links for an existing RSS feed, limiting the selection to the five most recent items: