Gazelle/classes/feed.class.php

<?php
class Feed
{
    public function open_feed()
    {
        header("Content-type: application/xml; charset=UTF-8");
        echo "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n","<rss xmlns:dc=\"http://purl.org/dc/elements/1.1/\" version=\"2.0\">\n\t<channel>\n";
    }

    public function close_feed()
    {
        echo "\t</channel>\n</rss>";
    }

    public function channel($Title, $Description, $Section = '')
    {
        $Site = site_url();
        echo "\t\t<title>$Title :: ". SITE_NAME. "</title>\n";
        echo "\t\t<link>$Site$Section</link>\n";
        echo "\t\t<description>$Description</description>\n";
        echo "\t\t<language>en-us</language>\n";
        echo "\t\t<lastBuildDate>". date('r'). "</lastBuildDate>\n";
        echo "\t\t<docs>http://blogs.law.harvard.edu/tech/rss</docs>\n";
        echo "\t\t<generator>Gazelle Feed Class</generator>\n\n";
    }

    public function item($Title, $Description, $Page, $Creator, $Comments = '', $Category = '', $Date = '')
    { // Escape with CDATA, otherwise the feed breaks.
        if ($Date === '') {
            $Date = date('r');
        } else {
            $Date = date('r', strtotime($Date));
        }
        $Site = site_url();
        $Item = "\t\t<item>\n";
        $Item .= "\t\t\t<title><![CDATA[$Title]]></title>\n";
        $Item .= "\t\t\t<description><![CDATA[$Description]]></description>\n";
        $Item .= "\t\t\t<pubDate>$Date</pubDate>\n";
        $Item .= "\t\t\t<link>$Site$Page</link>\n";
        $Item .= "\t\t\t<guid>$Site$Page</guid>\n";
        if ($Comments !== '') {
            $Item .= "\t\t\t<comments>$Site$Comments</comments>\n";
        }
        if ($Category !== '') {
            $Item .= "\t\t\t<category><![CDATA[$Category]]></category>\n";
        }
        $Item .= "\t\t\t<dc:creator>$Creator</dc:creator>\n\t\t</item>\n";
        return $Item;
    }

    public function retrieve($CacheKey, $AuthKey, $PassKey)
    {
        global $Cache;
        $Entries = $Cache->get_value($CacheKey);
        if (!$Entries) {
            $Entries = [];
        } else {
            foreach ($Entries as $Item) {
                echo str_replace(array('[[PASSKEY]]', '[[AUTHKEY]]'), array(display_str($PassKey), display_str($AuthKey)), $Item);
            }
        }
    }

    public function populate($CacheKey, $Item)
    {
        global $Cache;
        $Entries = $Cache->get_value($CacheKey, true);
        if (!$Entries) {
            $Entries = [];
        } else {
            if (count($Entries) >= 50) {
                array_pop($Entries);
            }
        }
        array_unshift($Entries, $Item);
        $Cache->cache_value($CacheKey, $Entries, 0); // inf cache
    }
}