← All changes | _inc/lib/class-jetpack-podcast-feed-locator.php +124 -0 16.2-beta → 16.3 View file →

		@@ -1,0 +1,124 @@
	1	+<?php
	2	+/**
	3	+ * Extension of the SimplePie\Locator class, to detect podcast feeds
	4	+ *
	5	+ * @package automattic/jetpack
	6	+ */
	7	+
	8	+if ( ! defined( 'ABSPATH' ) ) {
	9	+ exit( 0 );
	10	+}
	11	+
	12	+/**
	13	+ * Class Jetpack_Podcast_Feed_Locator
	14	+ */
	15	+class Jetpack_Podcast_Feed_Locator extends SimplePie\Locator {
	16	+
	17	+ /**
	18	+ * Overrides the locator is_feed function to check for
	19	+ * appropriate podcast elements.
	20	+ *
	21	+ * @param SimplePie\HTTP\Response $file The file being checked.
	22	+ * @param boolean $check_html Adds text/html to the mimetypes checked.
	23	+ */
	24	+ public function is_feed( $file, $check_html = false ) {
	25	+ return parent::is_feed( $file, $check_html ) &&
	26	+ $file instanceof SimplePie\File &&
	27	+ $this->is_podcast_feed( $file );
	28	+ }
	29	+
	30	+ /**
	31	+ * Checks the contents of the file for elements that make
	32	+ * it a podcast feed.
	33	+ *
	34	+ * @param SimplePie\File $file The file being checked.
	35	+ */
	36	+ private function is_podcast_feed( $file ) {
	37	+ // If we can't read the DOM assume it's a podcast feed, we'll work
	38	+ // it out later.
	39	+ if ( ! class_exists( 'DOMDocument' ) ) {
	40	+ return true;
	41	+ }
	42	+
	43	+ // @todo Drop is_callable check once WordPress.com Simple gets the SimplePie update that came with WordPress 6.9.
	44	+ if ( is_callable( array( $file, 'get_body_content' ) ) ) {
	45	+ $feed_dom = $this->safely_load_xml( $file->get_body_content() );
	46	+ } else {
	47	+ // @phan-suppress-next-line PhanDeprecatedProperty -- For compatibility only.
	48	+ $feed_dom = $this->safely_load_xml( (string) $file->body );
	49	+ }
	50	+
	51	+ // Do this as either/or but prioritise the itunes namespace. It's pretty likely
	52	+ // that it's a podcast feed we've found if that namespace is present.
	53	+ return $feed_dom && $this->has_itunes_ns( $feed_dom ) && $this->has_audio_enclosures( $feed_dom );
	54	+ }
	55	+
	56	+ /**
	57	+ * Safely loads an XML file
	58	+ *
	59	+ * @param string $xml A string of XML to load.
	60	+ * @return DOMDocument|false A resulting DOM document or `false` if there is an error.
	61	+ */
	62	+ private function safely_load_xml( $xml ) {
	63	+ if ( empty( $xml ) ) {
	64	+ return false;
	65	+ }
	66	+
	67	+ $disable_entity_loader = PHP_VERSION_ID < 80000;
	68	+
	69	+ if ( $disable_entity_loader ) {
	70	+ // This function has been deprecated in PHP 8.0 because in libxml 2.9.0, external entity loading
	71	+ // is disabled by default, so this function is no longer needed to protect against XXE attacks.
	72	+ // phpcs:ignore Generic.PHP.DeprecatedFunctions.Deprecated, PHPCompatibility.FunctionUse.RemovedFunctions.libxml_disable_entity_loaderDeprecated
	73	+ $loader = libxml_disable_entity_loader( true );
	74	+ }
	75	+
	76	+ $errors = libxml_use_internal_errors( true );
	77	+
	78	+ $return = new DOMDocument();
	79	+ if ( ! $return->loadXML( $xml ) ) {
	80	+ return false;
	81	+ }
	82	+
	83	+ libxml_use_internal_errors( $errors );
	84	+
	85	+ if ( $disable_entity_loader && isset( $loader ) ) {
	86	+ // phpcs:ignore Generic.PHP.DeprecatedFunctions.Deprecated, PHPCompatibility.FunctionUse.RemovedFunctions.libxml_disable_entity_loaderDeprecated
	87	+ libxml_disable_entity_loader( $loader );
	88	+ }
	89	+
	90	+ return $return;
	91	+ }
	92	+
	93	+ /**
	94	+ * Checks the RSS feed for the presence of the itunes podcast namespace.
	95	+ * It's pretty loose and just checks the URI for itunes.com
	96	+ *
	97	+ * @param DOMDocument $dom The XML document to check.
	98	+ * @return boolean Whether the itunes namespace is defined.
	99	+ */
	100	+ private function has_itunes_ns( $dom ) {
	101	+ $xpath = new DOMXPath( $dom );
	102	+ foreach ( $xpath->query( 'namespace::*' ) as $node ) {
	103	+ // phpcs:disable WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
	104	+ // nodeValue is not valid, but it's part of the DOM API that we don't control.
	105	+ if ( strstr( $node->nodeValue, 'itunes.com' ) ) {
	106	+ return true;
	107	+ }
	108	+ // phpcs:enable
	109	+ }
	110	+ return false;
	111	+ }
	112	+
	113	+ /**
	114	+ * Checks the RSS feed for the presence of enclosures with an audio mimetype.
	115	+ *
	116	+ * @param DOMDocument $dom The XML document to check.
	117	+ * @return boolean Whether enclosures were found.
	118	+ */
	119	+ private function has_audio_enclosures( $dom ) {
	120	+ $xpath = new DOMXPath( $dom );
	121	+ $enclosures = $xpath->query( "//enclosure[starts-with(@type,'audio/')]" );
	122	+ return ! $enclosures ? false : $enclosures->length > 0;
	123	+ }
	124	+}