Show FeedBurner Circulation using PHP

As it turns out, I'm not a fan of the Feedburner chicklet (as they call it) that gives you your total subscriber list. In fact, what if you wanted something a little more unique?

Borrowing heavily from this code example, I put together this quick script that pulls in your total circulation:

<?
// define parameters
$feedid = 'snookca';
$cache_time = '43200'; // in seconds (43200 = 24 hrs)
$feedburner_cache = 'feedburner_cache.txt' ;

// Make sure we cache data, so that we do not have to contact
// Feedburner for every request.
if (!file_exists($feedburner_cache) || (time() - $cache_time > filemtime($feedburner_cache))) {
    $tmp = file_get_contents('https://feedburner.google.com/api/awareness/1.0/GetFeedData?uri=' . $feedid) ;
    $fp = fopen($feedburner_cache,'w') ;
    fputs($fp, $tmp) ;
    fclose($fp) ;
}

// pull in data from cache
// $fp = fsockopen ($host, '80'); // (this also works)
$fp = fopen($feedburner_cache,'r') ;
if ($fp) {
	while (!feof($fp) ) {
	    $xml .= fgets($fp,1024) ;
	}
	preg_match("/circulation=\"(\d+)\"/i", $xml, $circulation);
	echo '(' . $circulation[1] . ')';
	fclose($fp) ;
}else{
	// fail silently
}
?>

To use this code, just replace snookca with your site id. What this does is reads in the xml response from the FeedBurner API (which must be turned on for your feed if you haven't done so already) and writes it to a file. Any subsequent request will read from the cache instead of hitting the web service again. Then, the script reads the file from the cache and does a regex to match the circulation="XX" part in the XML.

To see the code in action (at time of writing), check out the home page and look in the footer next to the link to the Technorati profile. That number in brackets is my circulation (currently zero... go figure).

Check out the FeedBurner Awareness API for more information.