If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting!

I have recently put up a list of DIGG popular stories on my sidebar. The reason for this was the advent of the new DIGG API which gives access to a whole range of data from the DIGG database.

There are already some good PHP classes to access the API but I wanted some thing quick and simple that would not put a lot of requirements on my current hosting (PHP 4). The API gives three very good ways to receive the data (XML, JSON and serialized PHP).

I quickly discovered that XML decoding under PHP 4 is a pain in the (****) when you do not have access to install further modules. So quickly moved onto JSON, but the lovely function json_decode is PHP 5 only. But I did a bit of search and found several PHP json classes without any dependencies. I had also ruled out the PHP serialised format as it tries to unserialise into classes that I do not have defined (again dependencies.)

I then added some caching as I really didnt want to upset the lovely people at DIGG with constant requests when the data was not likely to change much.

You can download the project (its only 2 files.) from the code bank area. It is not pretty code, and it’s not encapsulated in a class or anything as I did it purely for speed (of coding, and execution.)

Below are a few of the important sections.

$response = file_get_contents("http://services.digg.com/stories/container/
	$category/popular?appkey=$appkey&count=$count&type=json");
// create an instance of the JSON service
$json = new Services_JSON();
// Decode the JSON we requested
$decoded = $json->decode($response);

The URL is built up to retrieve only the popular stories from a specific category. (technology I have shown on my sidebar.) I then use the enclosed JSON decoder to convert that into a PHP array.

echo "
<ul>";
// Output the stories
foreach($decoded->stories as $story) {
	$title = $story->title;
	if($title != '') {
		if(strlen($title) > 30) {
			$title = substr($title,0,29).'...';
		}
		echo $title;
	}
}
echo "</ul>";

This iterates through the array and displays each in an unordered list. There is a lot more information stored within each of the stories but all I am displaying is the link.

And before someone comments that this could all be done via RSS, I agree, but I can easily now adapt what I have got to retrieve a whole range of different interesting lists.

Some ideas for what else to do with the DIGG API

• Extract out the users who have posted the popular stories
• Show the time difference between posting and the story becoming popular
• build up trends of the most popular posters
• Create custom tag clouds from the words supplied in the stories