root/tags/2.3.1/wp-includes/feed.php

<?php

function get_bloginfo_rss($show = '') {
    $info = strip_tags(get_bloginfo($show));
    return apply_filters('get_bloginfo_rss', convert_chars($info));
}


function bloginfo_rss($show = '') {
    echo apply_filters('bloginfo_rss', get_bloginfo_rss($show));
}

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;
}

function wp_title_rss($sep = '&#187;') {
    echo apply_filters('wp_title_rss', get_wp_title_rss($sep));
}

function get_the_title_rss() {
    $title = get_the_title();
    $title = apply_filters('the_title_rss', $title);
    return $title;
}


function the_title_rss() {
    echo get_the_title_rss();
}


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;
        }
        for ( $i=0; $i<$k; $i++ )
            $excerpt .= $blah[$i].' ';
        $excerpt .= ($use_dotdotdot) ? '...' : '';
        $content = $excerpt;
    }
    $content = str_replace(']]>', ']]&gt;', $content);
    echo $content;
}


function the_excerpt_rss() {
    $output = get_the_excerpt();
    echo apply_filters('the_excerpt_rss', $output);
}

function the_permalink_rss() {
    echo apply_filters('the_permalink_rss', get_permalink());

}

function comment_link() {
    echo get_comment_link();
}


function get_comment_author_rss() {
    return apply_filters('comment_author_rss', get_comment_author() );
}


function comment_author_rss() {
    echo get_comment_author_rss();
}


function comment_text_rss() {
    $comment_text = get_comment_text();
    $comment_text = apply_filters('comment_text_rss', $comment_text);
    echo $comment_text;
}


function comments_rss_link($link_text = 'Comments RSS', $commentsrssfilename = 'nolongerused') {
    $url = get_post_comments_feed_link();
    echo "<a href='$url'>$link_text</a>";
}


function comments_rss($commentsrssfilename = 'nolongerused') {
    return get_post_comments_feed_link();
}


function get_author_rss_link($echo = false, $author_id, $author_nicename) {
    $auth_ID = (int) $author_id;
    $permalink_structure = get_option('permalink_structure');

    if ( '' == $permalink_structure ) {
        $link = get_option('home') . '?feed=rss2&amp;author=' . $author_id;
    } else {
        $link = get_author_posts_url($author_id, $author_nicename);
        $link = trailingslashit($link) . user_trailingslashit('feed', 'feed');
    }

    $link = apply_filters('author_feed_link', $link);

    if ( $echo )
        echo $link;
    return $link;
}


function get_category_rss_link($echo = false, $cat_ID, $category_nicename) {
    $permalink_structure = get_option('permalink_structure');

    if ( '' == $permalink_structure ) {
        $link = get_option('home') . '?feed=rss2&amp;cat=' . $cat_ID;
    } else {
        $link = get_category_link($cat_ID);
        $link = trailingslashit($link) . user_trailingslashit('feed', 'feed');
    }

    $link = apply_filters('category_feed_link', $link);

    if ( $echo )
        echo $link;
    return $link;
}


function get_the_category_rss($type = 'rss') {
    $categories = get_the_category();
    $tags = get_the_tags();
    $home = get_bloginfo_rss('home');
    $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 )
            $the_list .= "\n\t\t<dc:subject><![CDATA[$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
            $the_list .= "\n\t\t<category><![CDATA[$cat_name]]></category>\n";
    }

    return apply_filters('the_category_rss', $the_list, $type);
}


function the_category_rss($type = 'rss') {
    echo get_the_category_rss($type);
}

function get_tag_feed_link($tag_id, $feed = 'rss2') {
    $tag_id = (int) $tag_id;

    $tag = get_tag($tag_id);

    if ( empty($tag) || is_wp_error($tag) )
        return false;

    $permalink_structure = get_option('permalink_structure');

    if ( '' == $permalink_structure ) {
        $link = get_option('home') . "?feed=$feed&amp;tag=" . $tag->slug;
    } else {
        $link = get_tag_link($tag->term_id);
        if ( 'rss2' == $feed )
            $feed_link = 'feed';
        else
            $feed_link = "feed/$feed";
        $link = $link . user_trailingslashit($feed_link, 'feed');
    }

    $link = apply_filters('tag_feed_link', $link, $feed);

    return $link;
}

function html_type_rss() {
    $type = get_bloginfo('html_type');
    if (strpos($type, 'xhtml') !== false)
        $type = 'xhtml';
    else
        $type = 'html';
    echo $type;
}


function rss_enclosure() {
    global $id, $post;
    if ( !empty($post->post_password) && ($_COOKIE['wp-postpass_'.COOKIEHASH] != $post->post_password) )
        return;

    foreach (get_post_custom() as $key => $val) {
        if ($key == 'enclosure') {
            foreach ((array)$val as $enc) {
                $enclosure = split("\n", $enc);
                echo apply_filters('rss_enclosure', '<enclosure url="' . trim(htmlspecialchars($enclosure[0])) . '" length="' . trim($enclosure[1]) . '" type="' . trim($enclosure[2]) . '" />' . "\n");
            }
        }
    }
}

function atom_enclosure() {
    global $id, $post;
    if ( !empty($post->post_password) && ($_COOKIE['wp-postpass_'.COOKIEHASH] != $post->post_password) )
        return;

    foreach (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");
            }
        }
    }
}

?>