Porting your game to Facebook, however, is not an easy job to do, especially if your game is deployed on multiple servers.

Browser Based Games found a solution for this. By using Browser Games Hub data and an OpenID provider, they provide players an easy way to play browser games with their Facebook or OpenSocial capable (Orkut, MySpace, Netlog, …) account.

OpenID?

This application requires OpenID support. OpenID is an open source system that enables users to use one identity across the web. Using one OpenID you can login to hundreds of websites without remembering all those passwords and logins.

Depending on how your game is written, OpenID is fairly simple to install. There are a lot of libraries in multiple languages and a rather extended quick guide can be found here.

On a sidenote, if your game supports OpenID, it will also support GalaxyNews ID, which is based on the OpenID technology.

Note: in order to add your game to the BBG application, your login script must receive the openid_url in GET, not in POST.

Adding your game
Next issue on the list is adding your game to BBG application. Since it uses the information provided by Browser Games Hub, you will have to add your game to the hub (see previous article). The most important section in your XML will be the servers element. If this section is invalid, your game will not appear in the application.

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<browsergameshub version="0.1">
	<servers>
		<server group="Pool A">
			<id>Server ID</id>
			<name>Server 2</name>
 
			<version>0.123</version>
			<game_url>http://link-to-your-game-server/</game_url>
			<openid_url>http://link-to-your-game-server/openid.php?openid_url=%s</openid_url>
			<players>2504</players>
 
			<status>open</status>
			<descriptions>
				<description lang="en">speed 1x</description>
			</descriptions>
 
		</server>
	</servers>
</browsergameshub>

Let’s take a closer look at the element openid_url:

			<openid_url>http://link-to-your-game-server/openid.php?openid_url=%s</openid_url>

This element should contain a direct link to the action of your OpenID login form. The GET variable declared in openid_url=%s will be populated with an OpenID. The Browser Games Hub will throw an error if it’s not working.

And next?

That’s it, really. Your game should now appear in the Hub with a lightning symbol, showing that your game supports OpenID. The application is only updated a few times a day, so it might take a while before all those facebook users start joining your game