<?php
/**
* WordPress Feed API
*
* Many of the functions used in here belong in The Loop, or The Loop for the
* Feeds.
*
* @package WordPress
* @subpackage Feed
* @since 2.1.0
*/
/**
* Retrieves RSS container for the bloginfo function.
*
* You can retrieve anything that you can using the get_bloginfo() function.
* Everything will be stripped of tags and characters converted, when the values
* are retrieved for use in the feeds.
*
* @since 1.5.1
*
* @see get_bloginfo() For the list of possible values to display.
*
* @param string $show See get_bloginfo() for possible values.
* @return string
*/
function get_bloginfo_rss( $show = '' ) {
$info = strip_tags( get_bloginfo( $show ) );
/**
* Filters the bloginfo for use in RSS feeds.
*
* @since 2.2.0
*
* @see convert_chars()
* @see get_bloginfo()
*
* @param string $info Converted string value of the blog information.
* @param string $show The type of blog information to retrieve.
*/
return apply_filters( 'get_bloginfo_rss', convert_chars( $info ), $show );
}
/**
* Displays RSS container for the bloginfo function.
*
* You can retrieve anything that you can using the get_bloginfo() function.
* Everything will be stripped of tags and characters converted, when the values
* are retrieved for use in the feeds.
*
* @since 0.71
*
* @see get_bloginfo() For the list of possible values to display.
*
* @param string $show See get_bloginfo() for possible values.
*/
function bloginfo_rss( $show = '' ) {
/**
* Filters the bloginfo for display in RSS feeds.
*
* @since 2.1.0
*
* @see get_bloginfo()
*
* @param string $rss_container RSS container for the blog information.
* @param string $show The type of blog information to retrieve.
*/
echo apply_filters( 'bloginfo_rss', get_bloginfo_rss( $show ), $show );
}
/**
* Retrieves the default feed.
*
* The default feed is 'rss2', unless a plugin changes it through the
* {@see 'default_feed'} filter.
*
* @since 2.5.0
*
* @return string Default feed, or for example 'rss2', 'atom', etc.
*/
function get_default_feed() {
/**
* Filters the default feed type.
*
* @since 2.5.0
*
* @param string $feed_type Type of default feed. Possible values include 'rss2', 'atom'.
* Default 'rss2'.
*/
$default_feed = apply_filters( 'default_feed', 'rss2' );
return ( 'rss' === $default_feed ) ? 'rss2' : $default_feed;
}
/**
* Retrieves the blog title for the feed title.
*
* @since 2.2.0
* @since 4.4.0 The optional `$sep` parameter was deprecated and renamed to `$deprecated`.
*
* @param string $deprecated Unused.
* @return string The document title.
*/
function get_wp_title_rss( $deprecated = '–' ) {
if ( '–' !== $deprecated ) {
/* translators: %s: 'document_title_separator' filter name. */
_deprecated_argument( __FUNCTION__, '4.4.0', sprintf( __( 'Use the %s filter instead.' ), '<code>document_title_separator</code>' ) );
}
/**
* Filters the blog title for use as the feed title.
*
* @since 2.2.0
* @since 4.4.0 The `$sep` parameter was deprecated and renamed to `$deprecated`.
*
* @param string $title The current blog title.
* @param string $deprecated Unused.
*/
return apply_filters( 'get_wp_title_rss', wp_get_document_title(), $deprecated );
}
/**
* Displays the blog title for display of the feed title.
*
* @since 2.2.0
* @since 4.4.0 The optional `$sep` parameter was deprecated and renamed to `$deprecated`.
*
* @param string $deprecated Unused.
*/
function wp_title_rss( $deprecated = '–' ) {
if ( '–' !== $deprecated ) {
/* translators: %s: 'document_title_separator' filter name. */
_deprecated_argument( __FUNCTION__, '4.4.0', sprintf( __( 'Use the %s filter instead.' ), '<code>document_title_separator</code>' ) );
}
/**
* Filters the blog title for display of the feed title.
*
* @since 2.2.0
* @since 4.4.0 The `$sep` parameter was deprecated and renamed to `$deprecated`.
*
* @see get_wp_title_rss()
*
* @param string $wp_title_rss The current blog title.
* @param string $deprecated Unused.
*/
echo apply_filters( 'wp_title_rss', get_wp_title_rss(), $deprecated );
}
/**
* Retrieves the current post title for the feed.
*
* @since 2.0.0
* @since 6.6.0 Added the `$post` parameter.
*
* @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
* @return string Current post title.
*/
function get_the_title_rss( $post = 0 ) {
$title = get_the_title( $post );
/**
* Filters the post title for use in a feed.
*
* @since 1.2.0
*
* @param string $title The current post title.
*/
return apply_filters( 'the_title_rss', $title );
}
/**
* Displays the post title in the feed.
*
* @since 0.71
*/
function the_title_rss() {
echo get_the_title_rss();
}
/**
* Retrieves the post content for feeds.
*
* @since 2.9.0
*
* @see get_the_content()
*
* @param string $feed_type The type of feed. rss2 | atom | rss | rdf
* @return string The filtered content.
*/
function get_the_content_feed( $feed_type = null ) {
if ( ! $feed_type ) {
$feed_type = get_default_feed();
}
/** This filter is documented in wp-includes/post-template.php */
$content = apply_filters( 'the_content', get_the_content() );
$content = str_replace( ']]>', ']]>', $content );
/**
* Filters the post content for use in feeds.
*
* @since 2.9.0
*
* @param string $content The current post content.
* @param string $feed_type Type of feed. Possible values include 'rss2', 'atom'.
* Default 'rss2'.
*/
return apply_filters( 'the_content_feed', $content, $feed_type );
}
/**
* Displays the post content for feeds.
*
* @since 2.9.0
*
* @param string $feed_type The type of feed. rss2 | atom | rss | rdf
*/
function the_content_feed( $feed_type = null ) {
echo get_the_content_feed( $feed_type );
}
/**
* Displays the post excerpt for the feed.
*
* @since 0.71
*/
function the_excerpt_rss() {
$output = get_the_excerpt();
/**
* Filters the post excerpt for a feed.
*
* @since 1.2.0
*
* @param string $output The current post excerpt.
*/
echo apply_filters( 'the_excerpt_rss', $output );
}
/**
* Displays the permalink to the post for use in feeds.
*
* @since 2.3.0
*/
function the_permalink_rss() {
/**
* Filters the permalink to the post for use in feeds.
*
* @since 2.3.0
*
* @param string $post_permalink The current post permalink.
*/
echo esc_url( apply_filters( 'the_permalink_rss', get_permalink() ) );
}
/**
* Outputs the link to the comments for the current post in an XML safe way.
*
* @since 3.0.0
*/
function comments_link_feed() {
/**
* Filters the comments permalink for the current post.
*
* @since 3.6.0
*
* @param string $comment_permalink The current comment permalink with
* '#comments' appended.
*/
echo esc_url( apply_filters( 'comments_link_feed', get_comments_link() ) );
}
/**
* Displays the feed GUID for the current comment.
*
* @since 2.5.0
*
* @param int|WP_Comment $comment_id Optional comment object or ID. Defaults to global comment object.
*/
function comment_guid( $comment_id = null ) {
echo esc_url( get_comment_guid( $comment_id ) );
}
/**
* Retrieves the feed GUID for the current comment.
*
* @since 2.5.0
*
* @param int|WP_Comment $comment_id Optional comment object or ID. Defaults to global comment object.
* @return string|false GUID for comment on success, false on failure.
*/
function get_comment_guid( $comment_id = null ) {
$comment = get_comment( $comment_id );
if ( ! is_object( $comment ) ) {
return false;
}
return get_the_guid( $comment->comment_post_ID ) . '#comment-' . $comment->comment_ID;
}
/**
* Displays the link to the comments.
*
* @since 1.5.0
* @since 4.4.0 Introduced the `$comment` argument.
*
* @param int|WP_Comment $comment Optional. Comment object or ID. Defaults to global comment object.
*/
function comment_link( $comment = null ) {
/**
* Filters the current comment's permalink.
*
* @since 3.6.0
*
* @see get_comment_link()
*
* @param string $comment_permalink The current comment permalink.
*/
echo esc_url( apply_filters( 'comment_link', get_comment_link( $comment ) ) );
}
/**
* Retrieves the current comment author for use in the feeds.
*
* @since 2.0.0
*
* @return string Comment Author.
*/
function get_comment_author_rss() {
/**
* Filters the current comment author for use in a feed.
*
* @since 1.5.0
*
* @see get_comment_author()
*
* @param string $comment_author The current comment author.
*/
return apply_filters( 'comment_author_rss', get_comment_author() );
}
/**
* Displays the current comment author in the feed.
*
* @since 1.0.0
*/
function comment_author_rss() {
echo get_comment_author_rss();
}
/**
* Displays the current comment content for use in the feeds.
*
* @since 1.0.0
*/
function comment_text_rss() {
$comment_text = get_comment_text();
/**
* Filters the current comment content for use in a feed.
*
* @since 1.5.0
*
* @param string $comment_text The content of the current comment.
*/
$comment_text = apply_filters( 'comment_text_rss', $comment_text );
echo $comment_text;
}
/**
* Retrieves all of the post categories, formatted for use in feeds.
*
* All of the categories for the current post in the feed loop, will be
* retrieved and have feed markup added, so that they can easily be added to the
* RSS2, Atom, or RSS1 and RSS0.91 RDF feeds.
*
* @since 2.1.0
*
* @param string $type Optional, default is the type returned by get_default_feed().
* @return string All of the post categories for displaying in the feed.
*/
function get_the_category_rss( $type = null ) {
if ( empty( $type ) ) {
$type = get_default_feed();
}
$categories = get_the_category();
$tags = get_the_tags();
$the_list = '';
$cat_names = array();
$filter = 'rss';
if ( 'atom' === $type ) {
$filter = 'raw';
}
if ( ! empty( $categories ) ) {
foreach ( (array) $categories as $category ) {
$cat_names[] = sanitize_term_field( 'name', $category->name, $category->term_id, 'category', $filter );
}
}
if ( ! empty( $tags ) ) {
foreach ( (array) $tags as $tag ) {
$cat_names[] = sanitize_term_field( 'name', $tag->name, $tag->term_id, 'post_tag', $filter );
}
}
$cat_names = array_unique( $cat_names );
foreach ( $cat_names as $cat_name ) {
if ( 'rdf' === $type ) {
$the_list .= "\t\t<dc:subject><![CDATA[$cat_name]]></dc:subject>\n";
} elseif ( 'atom' === $type ) {
$the_list .= sprintf( '<category scheme="%1$s" term="%2$s" />', esc_attr( get_bloginfo_rss( 'url' ) ), esc_attr( $cat_name ) );
} else {
$the_list .= "\t\t<category><![CDATA[" . html_entity_decode( $cat_name, ENT_COMPAT, get_option( 'blog_charset' ) ) . "]]></category>\n";
}
}
/**
* Filters all of the post categories for display in a feed.
*
* @since 1.2.0
*
* @param string $the_list All of the RSS post categories.
* @param string $type Type of feed. Possible values include 'rss2', 'atom'.
* Default 'rss2'.
*/
return apply_filters( 'the_category_rss', $the_list, $type );
}
/**
* Displays the post categories in the feed.
*
* @since 0.71
*
* @see get_the_category_rss() For better explanation.
*
* @param string $type Optional, default is the type returned by get_default_feed().
*/
function the_category_rss( $type = null ) {
echo get_the_category_rss( $type );
}
/**
* Displays the HTML type based on the blog setting.
*
* The two possible values are either 'xhtml' or 'html'.
*
* @since 2.2.0
*/
function html_type_rss() {
$type = get_bloginfo( 'html_type' );
if ( str_contains( $type, 'xhtml' ) ) {
$type = 'xhtml';
} else {
$type = 'html';
}
echo $type;
}
/**
* Displays the rss enclosure for the current post.
*
* Uses the global $post to check whether the post requires a password and if
* the user has the password for the post. If not then it will return before
* displaying.
*
* Also uses the function get_post_custom() to get the post's 'enclosure'
* metadata field and parses the value to display the enclosure(s). The
* enclosure(s) consist of enclosure HTML tag(s) with a URI and other
* attributes.
*
* @since 1.5.0
*/
function rss_enclosure() {
if ( post_password_required() ) {
return;
}
foreach ( (array) get_post_custom() as $key => $val ) {
if ( 'enclosure' === $key ) {
foreach ( (array) $val as $enc ) {
$enclosure = explode( "\n", $enc );
// Only get the first element, e.g. 'audio/mpeg' from 'audio/mpeg mpga mp2 mp3'.
$t = preg_split( '/[ \t]/', trim( $enclosure[2] ) );
$type = $t[0];
/**
* Filters the RSS enclosure HTML link tag for the current post.
*
* @since 2.2.0
*
* @param string $html_link_tag The HTML link tag with a URI and other attributes.
*/
echo apply_filters( 'rss_enclosure', '<enclosure url="' . esc_url( trim( $enclosure[0] ) ) . '" length="' . absint( trim( $enclosure[1] ) ) . '" type="' . esc_attr( $type ) . '" />' . "\n" );
}
}
}
}
/**
* Displays the atom enclosure for the current post.
*
* Uses the global $post to check whether the post requires a password and if
* the user has the password for the post. If not then it will return before
* displaying.
*
* Also uses the function get_post_custom() to get the post's 'enclosure'
* metadata field and parses the value to display the enclosure(s). The
* enclosure(s) consist of link HTML tag(s) with a URI and other attributes.
*
* @since 2.2.0
*/
function atom_enclosure() {
if ( post_password_required() ) {
return;
}
foreach ( (array) get_post_custom() as $key => $val ) {
if ( 'enclosure' === $key ) {
foreach ( (array) $val as $enc ) {
$enclosure = explode( "\n", $enc );
$url = '';
$type = '';
$length = 0;
$mimes = get_allowed_mime_types();
// Parse URL.
if ( isset( $enclosure[0] ) && is_string( $enclosure[0] ) ) {
$url = trim( $enclosure[0] );
}
// Parse length and type.
for ( $i = 1; $i <= 2; $i++ ) {
if ( isset( $enclosure[ $i ] ) ) {
if ( is_numeric( $enclosure[ $i ] ) ) {
$length = trim( $enclosure[ $i ] );
} elseif ( in_array( $enclosure[ $i ], $mimes, true ) ) {
$type = trim( $enclosure[ $i ] );
}
}
}
$html_link_tag = sprintf(
"<link href=\"%s\" rel=\"enclosure\" length=\"%d\" type=\"%s\" />\n",
esc_url( $url ),
esc_attr( $length ),
esc_attr( $type )
);
/**
* Filters the atom enclosure HTML link tag for the current post.
*
* @since 2.2.0
*
* @param string $html_link_tag The HTML link tag with a URI and other attributes.
*/
echo apply_filters( 'atom_enclosure', $html_link_tag );
}
}
}
}
/**
* Determines the type of a string of data with the data formatted.
*
* Tell whether the type is text, HTML, or XHTML, per RFC 4287 section 3.1.
*
* In the case of WordPress, text is defined as containing no markup,
* XHTML is defined as "well formed", and HTML as tag soup (i.e., the rest).
*
* Container div tags are added to XHTML values, per section 3.1.1.3.
*
* @link http://www.atomenabled.org/developers/syndication/atom-format-spec.php#rfc.section.3.1
*
* @since 2.5.0
*
* @param string $data Input string.
* @return array array(type, value)
*/
function prep_atom_text_construct( $data ) {
if ( ! str_contains( $data, '<' ) && ! str_contains( $data, '&' ) ) {
return array( 'text', $data );
}
if ( ! function_exists( 'xml_parser_create' ) ) {
wp_trigger_error( '', __( "PHP's XML extension is not available. Please contact your hosting provider to enable PHP's XML extension." ) );
return array( 'html', "<![CDATA[$data]]>" );
}
$parser = xml_parser_create();
xml_parse( $parser, '<div>' . $data . '</div>', true );
$code = xml_get_error_code( $parser );
xml_parser_free( $parser );
unset( $parser );
if ( ! $code ) {
if ( ! str_contains( $data, '<' ) ) {
return array( 'text', $data );
} else {
$data = "<div xmlns='http://www.w3.org/1999/xhtml'>$data</div>";
return array( 'xhtml', $data );
}
}
if ( ! str_contains( $data, ']]>' ) ) {
return array( 'html', "<![CDATA[$data]]>" );
} else {
return array( 'html', htmlspecialchars( $data ) );
}
}
/**
* Displays Site Icon in atom feeds.
*
* @since 4.3.0
*
* @see get_site_icon_url()
*/
function atom_site_icon() {
$url = get_site_icon_url( 32 );
if ( $url ) {
echo '<icon>' . convert_chars( $url ) . "</icon>\n";
}
}
/**
* Displays Site Icon in RSS2.
*
* @since 4.3.0
*/
function rss2_site_icon() {
$rss_title = get_wp_title_rss();
if ( empty( $rss_title ) ) {
$rss_title = get_bloginfo_rss( 'name' );
}
$url = get_site_icon_url( 32 );
if ( $url ) {
echo '
<image>
<url>' . convert_chars( $url ) . '</url>
<title>' . $rss_title . '</title>
<link>' . get_bloginfo_rss( 'url' ) . '</link>
<width>32</width>
<height>32</height>
</image> ' . "\n";
}
}
/**
* Returns the link for the currently displayed feed.
*
* @since 5.3.0
*
* @return string Correct link for the atom:self element.
*/
function get_self_link() {
$parsed = parse_url( home_url() );
$domain = $parsed['host'];
if ( isset( $parsed['port'] ) ) {
$domain .= ':' . $parsed['port'];
}
return set_url_scheme( 'http://' . $domain . wp_unslash( $_SERVER['REQUEST_URI'] ) );
}
/**
* Displays the link for the currently displayed feed in a XSS safe way.
*
* Generate a correct link for the atom:self element.
*
* @since 2.5.0
*/
function self_link() {
/**
* Filters the current feed URL.
*
* @since 3.6.0
*
* @see set_url_scheme()
* @see wp_unslash()
*
* @param string $feed_link The link for the feed with set URL scheme.
*/
echo esc_url( apply_filters( 'self_link', get_self_link() ) );
}
/**
* Gets the UTC time of the most recently modified post from WP_Query.
*
* If viewing a comment feed, the time of the most recently modified
* comment will be returned.
*
* @since 5.2.0
*
* @global WP_Query $wp_query WordPress Query object.
*
* @param string $format Date format string to return the time in.
* @return string|false The time in requested format, or false on failure.
*/
function get_feed_build_date( $format ) {
global $wp_query;
$datetime = false;
$max_modified_time = false;
$utc = new DateTimeZone( 'UTC' );
if ( ! empty( $wp_query ) && $wp_query->have_posts() ) {
// Extract the post modified times from the posts.
$modified_times = wp_list_pluck( $wp_query->posts, 'post_modified_gmt' );
// If this is a comment feed, check those objects too.
if ( $wp_query->is_comment_feed() && $wp_query->comment_count ) {
// Extract the comment modified times from the comments.
$comment_times = wp_list_pluck( $wp_query->comments, 'comment_date_gmt' );
// Add the comment times to the post times for comparison.
$modified_times = array_merge( $modified_times, $comment_times );
}
// Determine the maximum modified time.
$datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', max( $modified_times ), $utc );
}
if ( false === $datetime ) {
// Fall back to last time any post was modified or published.
$datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', get_lastpostmodified( 'GMT' ), $utc );
}
if ( false !== $datetime ) {
$max_modified_time = $datetime->format( $format );
}
/**
* Filters the date the last post or comment in the query was modified.
*
* @since 5.2.0
*
* @param string|false $max_modified_time Date the last post or comment was modified in the query, in UTC.
* False on failure.
* @param string $format The date format requested in get_feed_build_date().
*/
return apply_filters( 'get_feed_build_date', $max_modified_time, $format );
}
/**
* Returns the content type for specified feed type.
*
* @since 2.8.0
*
* @param string $type Type of feed. Possible values include 'rss', rss2', 'atom', and 'rdf'.
* @return string Content type for specified feed type.
*/
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';
/**
* Filters the content type for a specific feed type.
*
* @since 2.8.0
*
* @param string $content_type Content type indicating the type of data that a feed contains.
* @param string $type Type of feed. Possible values include 'rss', rss2', 'atom', and 'rdf'.
*/
return apply_filters( 'feed_content_type', $content_type, $type );
}
/**
* Builds SimplePie object based on RSS or Atom feed from URL.
*
* @since 2.8.0
*
* @param string|string[] $url URL of feed to retrieve. If an array of URLs, the feeds are merged
* using SimplePie's multifeed feature.
* See also {@link http://simplepie.org/wiki/faq/typical_multifeed_gotchas}
* @return SimplePie|WP_Error SimplePie object on success or WP_Error object on failure.
*/
function fetch_feed( $url ) {
if ( ! class_exists( '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();
$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();
// 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->set_file_class( 'WP_SimplePie_File' );
$feed->set_feed_url( $url );
/** 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 $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 ) );
$feed->init();
$feed->set_output_encoding( get_option( 'blog_charset' ) );
if ( $feed->error() ) {
return new WP_Error( 'simplepie-error', $feed->error() );
}
return $feed;
}