Emanuele Feronato

Talking about Actionscript 3, Facebook, Flash and Php.

It’s time to see how can we build a Flash Facebook application.

What we are going to do is a Flash movie to be embedded in a Facebook application, able to interact with the user by publishing notes and stories on the wall.

The first thing we need is the official Facebook Actionscript API. This library contains all we need to create a complete Facebook Flash application.

You can download the source code at this link, but before messing with AS3, let’s create the PHP part.

I suggest you to read the Developing a Facebook Application for absolute beginners posts from 1 to 5 if you don’t know how to create a basic Facebook application.

Then, take a look at the PHP code:

require_login();

$has_permission = $facebook->api_client->users_hasAppPermission("publish_stream");

if(!$has_permission){

?>

You won't be able to test the flash demo if you don't allow publish stream permission -

ALLOW PERMISSION

Notice at lines 1-3 the way you can import CSS style sheets. Don’t forget to use htmlentities on the imported file.

Then, at lines 5-9 I created a simple javascript function called grant that just redirects the browser to the application page. That is, basically it refreshes the page, and it will be called once the user will grant (or won’t grant) the permission to publish contents on his wall by submitting the permission form as you can see at line 30.

This is possible thanks to next_fbjs="grant()".

Another important thing in this script you should arleady know is the way I ask for publishing permission.

You can ask for permission inside the Flash movie itself but I found it easier to ask directly from Php. This way, you can even hide the Flash movie if the user does not grant permissions.

But the core of the script, the think you did not see in previous tutorials is the way I include the Flash movie at line 34 with the fb:swf tag.

You can find the official documentation at this page, and the most interesting thing is Facebook is passing some interesting parameters to the movie.

Let’s see the Actionscript now… I used the button component to create the buttons but this is not important… here it is the commented script:

package {
	import flash.display.Sprite;
	import fl.controls.Button;
	import flash.events.MouseEvent;
	import flash.text.TextField;
	// facebook rlibraries
	import com.facebook.Facebook;
	import com.facebook.utils.FacebookSessionUtil;
	import com.facebook.commands.notifications.*;
	import com.facebook.commands.stream.*;
	import com.facebook.net.FacebookCall;

	public class facebook_demo extends Sprite {
		var text_field:TextField = new TextField();
		var my_button:Button;
		var fbook:Facebook;
		// these are the api and secret keys you should be used to
		var api_key:String="xxxxxxxxxxxxxxx";
		var secret_key:String="yyyyyyyyyyyyyyyy";
		// starting a new facebook session
		var fb_session:FacebookSessionUtil=new FacebookSessionUtil(api_key,secret_key,loaderInfo);
		// in this object I will store all variables Facebook will pass to the movie
		var passed_vars:Object;
		// this variable will hold all facebook API calls
		var fbcall:FacebookCall;
		public function facebook_demo() {
			// just placing some buttons...
			place_buttons();
			// just creating a text field...
			create_text_field();
			// initializing the session
			fbook=fb_session.facebook;
			// this function will just print out all variables Facebook is passing to the movie
			get_vars();
		}
		// this is the core function, the one that will handle clicks on buttons and publising notes or stories according
		// to the button I am pressing
		function onclick(event:MouseEvent):void {
			// retrieving the user id (it's one of the variables passed by Facebook)
			var uid:Number=Number(passed_vars["fb_sig_user"]);
			switch (event.currentTarget.label) {
				case "Publish a note" :
					// publishing a note
					fbcall=new SendNotification([uid],"just sent a self-notification using Facebook Flash Demo","user_to_user");
					fbook.post(fbcall);
					break;
				case "Publish a story" :
					// publishing a story
					fbcall=new PublishPost("is using Facebook Flash Demo",{'href':'http://apps.facebook.com/flash_demo/','name':'Facebook Flash Demo','description':'that\'s it','caption':'this image was published by a Flash Movie','media':[{'type': 'image','src':  'http://www.gamemummy.com/facebook/flash_demo/api.jpg', 'href': 'http://apps.facebook.com/flash_demo/'}]},[{'href':'http://apps.facebook.com/flash_demo/','text':'Visit Facebook Flash Demo'}],uid.toString());
					fbook.post(fbcall);
			}
		}
		function create_text_field():void {
			addChild(text_field);
			text_field.width=500;
			text_field.height=320;
			text_field.x=10;
			text_field.y=10;
		}
		function get_vars():void {
			var varname:String;
			var varvalue:String;
			passed_vars=root.loaderInfo.parameters;
			text_field.text="DEFAULT VARS PASSED BY FACEBOOK:\n\n";
			for (varname in passed_vars) {
				varvalue=String(passed_vars[varname]);
				text_field.appendText(varname + ":\t" + varvalue + "\n");
			}
		}
		function place_buttons():void {
			var bnames:Array=new Array("Publish a note","Publish a story");
			for (var i:int=0; i<2; i++) {
				my_button=new Button();
				addChild(my_button);
				my_button.label=bnames[i];
				my_button.move(125+150*i, 350);
				my_button.addEventListener(MouseEvent.CLICK, onclick);
			}
		}
	}
}

The interesting thing of this script is the way you can send notifications (line 44) and publish posts (line 49)... I won't talk about notifications because Facebook will deprecate this method in late November/early December 2009 , but I want you to look at the way I publish the post following the format explained at the official attachment docs.

You can test the application at this page and download the full source code, library included.

Next time, we'll see how to add more functions.