PHP to filter/create feed

Question

I'm trying to use Simplepie to filter a feed for items that match a regex keyword filter, and then use those items to create another feed. However, I'm having trouble moving the items from the $matches array into the rss block. I'm still rather a novice with PHP, so maybe I'm missing something obvious, but would appreciate the help.

    <?php 
    $feed = new SimplePie();
    $feed->set_feed_url('feed://stackoverflow.com/feeds');
    $feed->init();

    $feed->set_cache_duration (3600);
    $feed->set_timeout(30);
    $feed->handle_content_type(); 

    $countItem = 0;
    foreach ($feed->get_items() as $item):
    $checktitle = $item->get_title();
    //Regex keyword filter
    $pattern = '/php/i';
    //If the there is a keyword match, store in $matches array
    if (preg_match($pattern, $checktitle)) {
        $matches[$countItem]= $item;
        $countItem++;
    }
    endforeach
    ?>

    <?php if ($success) {
    $itemlimit=0;
    foreach($matches as $item) {
    if ($itemlimit==20) { break; }
    ?>
    //rss block
    <item>
    <title><?php $item->get_title()); ?></title>       
    <link><?php echo $item->get_permalink(); ?></link>
    <pubDate><?php echo $item->get_date();></pubDate> 
    <description><![CDATA[<?php echo $item->get_description(); ?>]]></description>
    <content:encoded><![CDATA[<?php $item->get_content(); ?>]]></content:encoded>
    </item>
    <?
    $itemlimit = $itemlimit + 1;
    }
    }
    ?>

Answer 1

Is your $success being set somewhere? (You did ask if you were missing something obvious! :D)