Wikipedia Web Service in Flex

Currently I’m working on a Flexified version 2 of my guitarscales app. One of the new features is a short description of the chosen scale. Because I’m too lazy to write all these descriptions myself and because Wikipedia already has a lot of them, I decided to look around for a webservice to do this job for me.

The first place to start is ofcourse Wikipedia itself. Unfortunately, they do not have such a webservice. Although I do believe they are working on one.

After some googling I finally found the FUTEF Wikipedia API. This is a RESTful webservice and returns a string containing a JSON object. Since both ActionScript and JavaScript are based on ECMAScript, I can use the returned JSON object in my Flex application.

Because of the Security sandbox restrictions I cannot call the web service directly. As a workaround I’ll call the webservice from a local PHP file:

$keyword = $_GET["query"];
$request =  "http://api.futef.com/api/v1?query=".$keyword."&appid=[please contact FUTEF to request a free appid]&begin=0&end=1";
$xml = file_get_contents($request);

Then I can call this local PHP file from within my Flex application:

var service:HTTPService = new HTTPService();
service.url = "myphpfile.php?query=" + keyword;
service.addEventListener(ResultEvent.RESULT, wikipediaResultHandler);
service.send();

In the callback function I can now create a JSON object from the returned string:

private function wikipediaResultHandler(event:ResultEvent):void {
	var value:Object = JSON.decode( event.result as String );
	var resultText:String = value.records[0].text;
	var newLinePattern:RegExp = /\n/g;

	resultText = resultText.replace(newLinePattern, "");
	txtDescription.htmlText = resultText + "...<br/><a href=\""+value.records[0].url+"\" target=\"_blank\">Read more</a>";
}

Adobe has released several free and open ActionScript 3.0 APIs, including the JSON API that I used in this example. You can download this API here.