+/**
+ * Return the content type for specified feed type.
+ *
+ * @package WordPress
+ * @subpackage Feed
+ * @since 2.8.0
+ */
+function feed_content_type( $type = '' ) {
+ if ( empty($type) )
+ $type = get_default_feed();
+
+ $types = array(
+ 'rss' => 'application/rss+xml',
+ 'rss2' => 'application/rss+xml',
+ 'rss-http' => 'text/xml',
+ 'atom' => 'application/atom+xml',
+ 'rdf' => 'application/rdf+xml'
+ );
+
+ $content_type = ( !empty($types[$type]) ) ? $types[$type] : 'application/octet-stream';
+
+ return apply_filters( 'feed_content_type', $content_type, $type );
+}
+
+/**
+ * Build SimplePie object based on RSS or Atom feed from URL.
+ *
+ * @since 2.8
+ *
+ * @param string $url URL to retrieve feed
+ * @return WP_Error|SimplePie WP_Error object on failure or SimplePie object on success
+ */
+function fetch_feed($url) {
+ require_once (ABSPATH . WPINC . '/class-feed.php');
+
+ $feed = new SimplePie();
+
+ $feed->set_sanitize_class( 'WP_SimplePie_Sanitize_KSES' );
+ // 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();
+
+ $feed->set_cache_class( 'WP_Feed_Cache' );
+ $feed->set_file_class( 'WP_SimplePie_File' );
+
+ $feed->set_feed_url($url);
+ $feed->set_cache_duration( apply_filters( 'wp_feed_cache_transient_lifetime', 12 * HOUR_IN_SECONDS, $url ) );
+ do_action_ref_array( 'wp_feed_options', array( &$feed, $url ) );
+ $feed->init();
+ $feed->handle_content_type();
+
+ if ( $feed->error() )
+ return new WP_Error('simplepie-error', $feed->error());
+
+ return $feed;
+}