RSS API

Overview

The RSS API is a core system in Moodle to allow you to create secure RSS feeds of data in your module.

These RSS feeds can then be syndicated by other websites or aggregated by a feed reader.

Any Moodle module can generate RSS feeds to allow secure access to it's data.

File Locations

The primary functions for the RSS API is located in lib/rsslib.php

Additional functions and usage examples can be found in the following files:

blog/rsslib.php
mod/data/rsslib.php
mod/forum/rsslib.php
mod/glossary/rsslib.php

Examples

Below you will find examples on how to use the RSS functions within your own modules.

Creating an RSS feed

This example shows how you can create the content of an RSS Feed. (Example taken from blog/rsslib.php)

$tagid = 0;
// Get all the entries from the database
require_once($CFG->dirroot .'/blog/locallib.php');
$blogheaders = blog_get_headers($courseid, $groupid, $userid, $tagid);

$bloglisting = new blog_listing($blogheaders['filters']);
$blogentries = $bloglisting->get_entries();

foreach ($blogentries as $blog_entry) {
    $item = NULL;
    $item->author = fullname($DB->get_record('user', array('id'=>$blog_entry->userid)));
    $item->title = $blog_entry->subject;
    $item->pubdate = $blog_entry->lastmodified;
    $item->link = $CFG->wwwroot.'/blog/index.php?entryid='.$blog_entry->id;
    $item->description = format_text($blog_entry->summary, $blog_entry->format);
    if ( !empty($CFG->usetags) && ($blogtags = tag_get_tags_array('post', $blog_entry->id)) ) {
        if ($blogtags) {
            $item->tags = $blogtags;
        }
        $item->tagscheme = $CFG->wwwroot . '/tag';
    }
    $items[] = $item;
}
$content = rss_add_items($items);   /// Change structure to XML
$info .= ': '.$DB->get_field('tags', 'text', array('id'=>$tagid));

$header = rss_standard_header(get_string($type.'blog','blog', $info), $CFG->wwwroot.'/blog/index.php', get_string('intro','blog'));
$footer = rss_standard_footer();

$rssdata = $header.$content.$footer; // This is the complete RSS FEED

Caching an RSS feed

Following on from the previous example:

 $filename = "$CFG->cachedir/rss/blog/user/0/$tagid.xml";
 rss_save_file('blog', $filename, $contents, true);

Linking to a RSS feed

This example shows how you can output a link to an RSS feed. (Example taken from blocks/news_items/block_news_items.php)

$cm = $modinfo->instances['forum'][$forum->id];
$context = get_context_instance(CONTEXT_MODULE, $cm->id);
$forum = forum_get_course_forum($this->page->course->id, 'news');
$userid = (!isloggedin()) ? 0 : $USER->id;
$tooltiptext = get_string('rsssubscriberssposts','forum');
echo rss_get_link($context->id, $userid, 'mod_forum', $forum->id, $tooltiptext);

Documentation