Creating Badge Kit Services

Creating services for the Badge Kit is simple if you have a bit of ActionScript knowledge. Since the framework is already there, it's easy for you to plug in your service URLs, tweak the parameters, and be on your way. I'll go over some of the steps you'll want to follow in order to make your service compatible with the Badge Kit.

Creating a Service

First of all, in order to have a common language for the Badge Kit, all services need to have the same API for sending and receiving results. To easily accomplish this, any service must implement the Interface com.yahoo.webapis.IService. All this does is ensure that you've created the same methods for sending and returning results.

The interface IService sets up two methods that you'll need to implement:

1. send, which sends the service: function send(parameters:Object = null):void;
2. a getter to access the service results: function get lastResult():Object;

Here's a example of a service that was created for the WTH badge. This service simply downloads an RSS feed of odd news and parses it into an array. I've simplified the source code a bit for readability.

First, we declared the service, implementing IService. We placed this code into an AS file called OddNewsRSSService.as, under that example's source folder. Then we implemented the two necessary methods, send() and get lastResult().

In the send() method, we create a loader to do the downloading of the RSS feed. We set up an event listener so when it's done downloading, it will parse through the results and place them into an array. Using the get lastResult() method, we return this array of items we've parsed out. Now we can access this information from the service's lastResult property in the badge's content.xml.

package { import flash.events.Event; import flash.events.EventDispatcher; import flash.events.IEventDispatcher; import flash.net.*; import com.yahoo.webapis.IService; public class OddNewsRSSService extends EventDispatcher implements IService { // data arrays for holding result data public var parsedData:Array = new Array(); // last result function implementation public function get lastResult():Object { return parsedData; } // Send function implentation initiating the RSS feed public function send(parameters:Object = null):void { var serviceURL:String = "http://rss.news.yahoo.com/rss/oddlyenough"; var loader:URLLoader = new URLLoader(); loader.addEventListener(Event.COMPLETE, resultHandler); loader.load(new URLRequest(serviceURL)); } // result handler stuffing the RSS data into the data arrays private function resultHandler(ev:Event):void { var result:XML = new XML(ev.target.data); var items:XMLList = result..item; var len:int = items.length(); parsedData = []; namespace media= "http://search.yahoo.com/mrss/" use namespace media; // going over the result XML and taking out the individual fields for (var i:int = 0; i<len; i++) { parsedData.push(items[i]); } // create the "result" event for the Badge Kit var event:Event = new Event('result'); dispatchEvent(event); } } }

For more information on this service, see the WTH badge in your Examples folder where you installed the Badge Kit.

For more info on sending and receiving data in Flash, see the LiveDocs article Working with external data.

To see an example of a full service, and for copy-and-paste code that you can use in your own services, check out the source code for the Yahoo! Search Service, included in the Badge Kit source at com/yahoo/webapis/search/SearchService.

Deployment

Finally, when you've tested your service and are ready to deploy it, you'll want to compile it into a SWF that you'll be able to import into your badge. For more information on compiling, see the article Deploying Items to the Badge Kit.