WordPress/wp-includes/feed.php

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<?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
*/
/**
* 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.
*
* @package WordPress
* @subpackage Feed
* @since 1.5.1
* @uses apply_filters() Calls 'get_bloginfo_rss' hook with two parameters.
* @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));
return apply_filters('get_bloginfo_rss', convert_chars($info), $show);
}
/**
* Display 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.
*
* @package WordPress
* @subpackage Feed
* @since 0.71
* @uses apply_filters() Calls 'bloginfo_rss' hook with two parameters.
* @see get_bloginfo() For the list of possible values to display.
*
* @param string $show See get_bloginfo() for possible values.
*/
function bloginfo_rss($show = '') {
echo apply_filters('bloginfo_rss', get_bloginfo_rss($show), $show);
}
/**
* Retrieve the default feed.
*
* The default feed is 'rss2', unless a plugin changes it through the
* 'default_feed' filter.
*
* @package WordPress
* @subpackage Feed
* @since 2.5
* @uses apply_filters() Calls 'default_feed' hook on the default feed string.
*
* @return string Default feed, or for example 'rss2', 'atom', etc.
*/
function get_default_feed() {
return apply_filters('default_feed', 'rss2');
}
/**
* Retrieve the blog title for the feed title.
*
* @package WordPress
* @subpackage Feed
* @since 2.2.0
* @uses apply_filters() Calls 'get_wp_title_rss' hook on title.
* @uses wp_title() See function for $sep parameter usage.
*
* @param string $sep Optional.How to separate the title. See wp_title() for more info.
* @return string Error message on failure or blog title on success.
*/
function get_wp_title_rss($sep = '&#187;') {
$title = wp_title($sep, false);
if ( is_wp_error( $title ) )
return $title->get_error_message();
$title = apply_filters('get_wp_title_rss', $title);
return $title;
}
/**
* Display the blog title for display of the feed title.
*
* @package WordPress
* @subpackage Feed
* @since 2.2.0
* @uses apply_filters() Calls 'wp_title_rss' on the blog title.
* @see wp_title() $sep parameter usage.
*
* @param string $sep Optional.
*/
function wp_title_rss($sep = '&#187;') {
echo apply_filters('wp_title_rss', get_wp_title_rss($sep));
}
/**
* Retrieve the current post title for the feed.
*
* @package WordPress
* @subpackage Feed
* @since 2.0.0
* @uses apply_filters() Calls 'the_title_rss' on the post title.
*
* @return string Current post title.
*/
function get_the_title_rss() {
$title = get_the_title();
$title = apply_filters('the_title_rss', $title);
return $title;
}
/**
* Display the post title in the feed.
*
* @package WordPress
* @subpackage Feed
* @since 0.71
* @uses get_the_title_rss() Used to retrieve current post title.
*/
function the_title_rss() {
echo get_the_title_rss();
}
/**
* Display the post content for the feed.
*
* For encoding the html or the $encode_html parameter, there are three possible
* values. '0' will make urls footnotes and use make_url_footnote(). '1' will
* encode special characters and automatically display all of the content. The
* value of '2' will strip all HTML tags from the content.
*
* Also note that you cannot set the amount of words and not set the html
* encoding. If that is the case, then the html encoding will default to 2,
* which will strip all HTML tags.
*
* To restrict the amount of words of the content, you can use the cut
* parameter. If the content is less than the amount, then there won't be any
* dots added to the end. If there is content left over, then dots will be added
* and the rest of the content will be removed.
*
* @package WordPress
* @subpackage Feed
* @since 0.71
* @uses apply_filters() Calls 'the_content_rss' on the content before processing.
* @see get_the_content() For the $more_link_text, $stripteaser, and $more_file
* parameters.
*
* @param string $more_link_text Optional. Text to display when more content is available but not displayed.
* @param int|bool $stripteaser Optional. Default is 0.
* @param string $more_file Optional.
* @param int $cut Optional. Amount of words to keep for the content.
* @param int $encode_html Optional. How to encode the content.
*/
function the_content_rss($more_link_text='(more...)', $stripteaser=0, $more_file='', $cut = 0, $encode_html = 0) {
$content = get_the_content($more_link_text, $stripteaser, $more_file);
$content = apply_filters('the_content_rss', $content);
if ( $cut && !$encode_html )
$encode_html = 2;
if ( 1== $encode_html ) {
$content = wp_specialchars($content);
$cut = 0;
} elseif ( 0 == $encode_html ) {
$content = make_url_footnote($content);
} elseif ( 2 == $encode_html ) {
$content = strip_tags($content);
}
if ( $cut ) {
$blah = explode(' ', $content);
if ( count($blah) > $cut ) {
$k = $cut;
$use_dotdotdot = 1;
} else {
$k = count($blah);
$use_dotdotdot = 0;
}
/** @todo Check performance, might be faster to use array slice instead. */
for ( $i=0; $i<$k; $i++ )
$excerpt .= $blah[$i].' ';
$excerpt .= ($use_dotdotdot) ? '...' : '';
$content = $excerpt;
}
$content = str_replace(']]>', ']]&gt;', $content);
echo $content;
}
/**
* Display the post excerpt for the feed.
*
* @package WordPress
* @subpackage Feed
* @since 0.71
* @uses apply_filters() Calls 'the_excerpt_rss' hook on the excerpt.
*/
function the_excerpt_rss() {
$output = get_the_excerpt();
echo apply_filters('the_excerpt_rss', $output);
}
/**
* Display the permalink to the post for use in feeds.
*
* @package WordPress
* @subpackage Feed
* @since 2.3.0
* @uses apply_filters() Call 'the_permalink_rss' on the post permalink
*/
function the_permalink_rss() {
echo apply_filters('the_permalink_rss', get_permalink());
}
/**
* Display the feed GUID for the current comment.
*
* @package WordPress
* @subpackage Feed
* @since unknown
*
* @param int|object $comment_id Optional comment object or id. Defaults to global comment object.
*/
function comment_guid($comment_id = null) {
echo get_comment_guid($comment_id);
}
/**
* Retrieve the feed GUID for the current comment.
*
* @package WordPress
* @subpackage Feed
* @since unknown
*
* @param int|object $comment_id Optional comment object or id. Defaults to global comment object.
* @return bool|string false on failure or guid for comment on success.
*/
function get_comment_guid($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;
}
/**
* Display the link to the comments.
*
* @since 1.5.0
*/
function comment_link() {
echo clean_url( get_comment_link() );
}
/**
* Retrieve the current comment author for use in the feeds.
*
* @package WordPress
* @subpackage Feed
* @since 2.0.0
* @uses apply_filters() Calls 'comment_author_rss' hook on comment author.
* @uses get_comment_author()
*
* @return string Comment Author
*/
function get_comment_author_rss() {
return apply_filters('comment_author_rss', get_comment_author() );
}
/**
* Display the current comment author in the feed.
*
* @package WordPress
* @subpackage Feed
* @since 1.0.0
*/
function comment_author_rss() {
echo get_comment_author_rss();
}
/**
* Display the current comment content for use in the feeds.
*
* @package WordPress
* @subpackage Feed
* @since 1.0.0
* @uses apply_filters() Calls 'comment_text_rss' filter on comment content.
* @uses get_comment_text()
*/
function comment_text_rss() {
$comment_text = get_comment_text();
$comment_text = apply_filters('comment_text_rss', $comment_text);
echo $comment_text;
}
/**
* Retrieve 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.
*
* @package WordPress
* @subpackage Feed
* @since 2.1.0
* @uses apply_filters()
*
* @param string $type Optional, default is 'rss'. Either 'rss', 'atom', or 'rdf'.
* @return string All of the post categories for displaying in the feed.
*/
function get_the_category_rss($type = 'rss') {
$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" />', attribute_escape( apply_filters( 'get_bloginfo_rss', get_bloginfo( 'url' ) ) ), attribute_escape( $cat_name ) );
else
$the_list .= "\t\t<category><![CDATA[" . @html_entity_decode( $cat_name, ENT_COMPAT, get_option('blog_charset') ) . "]]></category>\n";
}
return apply_filters('the_category_rss', $the_list, $type);
}
/**
* Display the post categories in the feed.
*
* @package WordPress
* @subpackage Feed
* @since 0.71
* @see get_the_category_rss() For better explanation.
*
* @param string $type Optional, default is 'rss'. Either 'rss', 'atom', or 'rdf'.
*/
function the_category_rss($type = 'rss') {
echo get_the_category_rss($type);
}
/**
* Display the HTML type based on the blog setting.
*
* The two possible values are either 'xhtml' or 'html'.
*
* @package WordPress
* @subpackage Feed
* @since 2.2.0
*/
function html_type_rss() {
$type = get_bloginfo('html_type');
if (strpos($type, 'xhtml') !== false)
$type = 'xhtml';
else
$type = 'html';
echo $type;
}
/**
* Display 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.
*
* @package WordPress
* @subpackage Template
* @since 1.5.0
* @uses apply_filters() Calls 'rss_enclosure' hook on rss enclosure.
* @uses get_post_custom() To get the current post enclosure metadata.
*/
function rss_enclosure() {
if ( post_password_required() )
return;
foreach ( (array) get_post_custom() as $key => $val) {
if ($key == 'enclosure') {
foreach ( (array) $val as $enc ) {
$enclosure = explode("\n", $enc);
//only get the the first element eg, audio/mpeg from 'audio/mpeg mpga mp2 mp3'
$t = preg_split('/[ \t]/', trim($enclosure[2]) );
$type = $t[0];
echo apply_filters('rss_enclosure', '<enclosure url="' . trim(htmlspecialchars($enclosure[0])) . '" length="' . trim($enclosure[1]) . '" type="' . $type . '" />' . "\n");
}
}
}
}
/**
* Display 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.
*
* @package WordPress
* @subpackage Template
* @since 2.2.0
* @uses apply_filters() Calls 'atom_enclosure' hook on atom enclosure.
* @uses get_post_custom() To get the current post enclosure metadata.
*/
function atom_enclosure() {
if ( post_password_required() )
return;
foreach ( (array) get_post_custom() as $key => $val ) {
if ($key == 'enclosure') {
foreach ( (array) $val as $enc ) {
$enclosure = split("\n", $enc);
echo apply_filters('atom_enclosure', '<link href="' . trim(htmlspecialchars($enclosure[0])) . '" rel="enclosure" length="' . trim($enclosure[1]) . '" type="' . trim($enclosure[2]) . '" />' . "\n");
}
}
}
}
/**
* Determine 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
*
* @package WordPress
* @subpackage Feed
* @since 2.5
*
* @param string $data Input string
* @return array array(type, value)
*/
function prep_atom_text_construct($data) {
if (strpos($data, '<') === false && strpos($data, '&') === false) {
return array('text', $data);
}
$parser = xml_parser_create();
xml_parse($parser, '<div>' . $data . '</div>', true);
$code = xml_get_error_code($parser);
xml_parser_free($parser);
if (!$code) {
if (strpos($data, '<') === false) {
return array('text', $data);
} else {
$data = "<div xmlns='http://www.w3.org/1999/xhtml'>$data</div>";
return array('xhtml', $data);
}
}
if (strpos($data, ']]>') == false) {
return array('html', "<![CDATA[$data]]>");
} else {
return array('html', htmlspecialchars($data));
}
}
/**
* Display the link for the currently displayed feed in a XSS safe way.
*
* Generate a correct link for the atom:self element.
*
* @package WordPress
* @subpackage Feed
* @since 2.5
*/
function self_link() {
$host = @parse_url(get_option('home'));
$host = $host['host'];
echo clean_url(
'http'
. ( (isset($_SERVER['https']) && $_SERVER['https'] == 'on') ? 's' : '' ) . '://'
. $host
. stripslashes($_SERVER['REQUEST_URI'])
);
}
/**
* 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',
'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();
$feed->set_feed_url($url);
$feed->set_cache_class('WP_Feed_Cache');
$feed->set_file_class('WP_SimplePie_File');
$feed->set_cache_duration(43200);
$feed->init();
$feed->handle_content_type();
if ( $feed->error() )
return new WP_Error('simplepie-error', $feed->error());
return $feed;
}