HTML Examples/WP.iso/wordpress/wp-includes/feed.php

PHP Script | 2017-11-29 | 19.1 KB | 711 lines

<?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
 */

/**
 * 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 );
}

/**
 * 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.
 *
 * @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 );
}

/**
 * Retrieve 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;
}

/**
 * Retrieve 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 );
}

/**
 * Display 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 );
}

/**
 * Retrieve the current post title for the feed.
 *
 * @since 2.0.0
 *
 * @return string Current post title.
 */
function get_the_title_rss() {
    $title = get_the_title();

    /**
     * Filters the post title for use in a feed.
     *
     * @since 1.2.0
     *
     * @param string $title The current post title.
     */
    $title = apply_filters( 'the_title_rss', $title );
    return $title;
}

/**
 * Display the post title in the feed.
 *
 * @since 0.71
 */
function the_title_rss() {
    echo get_the_title_rss();
}

/**
 * Retrieve 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 );
}

/**
 * Display 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);
}

/**
 * Display 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 );
}

/**
 * Display 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
 * @return none
 */
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() ) );
}

/**
 * Display 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) );
}

/**
 * Retrieve the feed GUID for the current comment.
 *
 * @since 2.5.0
 *
 * @param int|WP_Comment $comment_id Optional comment object or id. Defaults to global comment object.
 * @return false|string false on failure or guid for comment on success.
 */
function get_comment_guid($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
 * @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 ) ) );
}

/**
 * Retrieve 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() );
}

/**
 * Display the current comment author in the feed.
 *
 * @since 1.0.0
 */
function comment_author_rss() {
    echo get_comment_author_rss();
}

/**
 * Display 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;
}

/**
 * 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.
 *
 * @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 );
}

/**
 * Display 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);
}

/**
 * Display 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() {
    $type = get_bloginfo('html_type');
    if (strpos($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.
 *
 * @since 1.5.0
 */
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 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" );
            }
        }
    }
}

/**
 * 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.
 *
 * @since 2.2.0
 */
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 = explode("\n", $enc);
                /**
                 * 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', '<link href="' . esc_url( trim( $enclosure[0] ) ) . '" rel="enclosure" length="' . absint( trim( $enclosure[1] ) ) . '" type="' . esc_attr( 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
 *
 * @since 2.5.0
 *
 * @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);
    }

    if ( ! function_exists( 'xml_parser_create' ) ) {
        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);

    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));
    }
}

/**
 * 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 ( $url ) {
        echo "<icon>$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";
    }
}

/**
 * Display 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() {
    $host = @parse_url(home_url());
    /**
     * 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', set_url_scheme( 'http://' . $host['host'] . wp_unslash( $_SERVER['REQUEST_URI'] ) ) ) );
}

/**
 * Return 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'.
 */
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 );
}

/**
 * Build SimplePie object based on RSS or Atom feed from URL.
 *
 * @since 2.8.0
 *
 * @param mixed $url URL of feed to retrieve. If an array of URLs, the feeds are merged
 * using SimplePie's multifeed feature.
 * See also {@link ΓÇïhttp://simplepie.org/wiki/faq/typical_multifeed_gotchas}
 *
 * @return WP_Error|SimplePie WP_Error object on failure or SimplePie object on success
 */
function fetch_feed( $url ) {
    if ( ! class_exists( 'SimplePie', false ) ) {
        require_once( ABSPATH . WPINC . '/class-simplepie.php' );
    }

    require_once( ABSPATH . WPINC . '/class-wp-feed-cache.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();

    $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 object $feed SimplePie feed object (passed by reference).
     * @param mixed  $url  URL of feed to retrieve. If an array of URLs, the feeds are merged.
     */
    do_action_ref_array( 'wp_feed_options', array( &$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;
}