Facebook Apps 101: Secrets of Facebook Apps Revealed!
What is a Facebook App?
nFusion has started to get more involved on Facebook, and part of that involvement means developing Facebook applications (“apps”). But what are Facebook apps? They’re what people use to send thousands of harassing requests to your inbox, right? Well, yes, and they’re also those little boxes that you can put into your profile and use to send people icons (or “gifts”), show people what countries you’ve been to or what movies you have seen and, of course, you use them to “poke” people. These are things that Facebook apps do, but what are they, really?
The Basics
An app is simply a special type of website that Facebook knows how to interact with. That’s all it is! Creating an app for the Facebook website is really just creating a group of settings that tells Facebook how to interact with your website — your app. The app displays information the way a normal website does, but it also has the ability to interface with the Facebook server to get information about the person who is using the app. It also has the ability to grab information about the user’s friends and do things like post messages and send invites.
To create a new Facebook app, go to http://www.Facebook.com/developers/ and click on the button, “Set Up New Application.” The most important thing when developing a Facebook app is to define the “Canvas Callback URL.” The Canvas Callback URL is the page that is displayed when the application first starts. Let’s say a user adds your application into a box on his profile. Every time the user looks at his profile, Facebook loads your application’s page from your server and places it into the box on the user’s profile page.
Two Main Types of App
There is one major choice that app developers need to make when creating a Facebook app: FBML or iframe.
FBML: FBML stands for Facebook Markup Language. When a Facebook user loads an application written in FBML onto his or her Facebook page, the Facebook server connects to the app’s Web server and injects the FBML-based app directly onto the user’s Facebook page. FBML is a markup language that contains a limited set of HTML tags, as well as tags for a lot of Facebook-specific elements, such as friend selectors, tab boxes, photo tags and much more. The HTML tags you may use are limited for security reasons because the markup looks as if it comes directly from Facebook and Facebook does not want to give third parties a chance to run any malicious code or modify a user’s page beyond the limits of what can be seen in the app box.
iframe: When an application is written as an iframe application, Facebook handles it a little bit differently. Rather than load a page from the application server and put it on a user’s Facebook page, the way Facebook does with an FBML app, Facebook places an iframe tag on the user’s page and gives the Web browser the URL of the Facebook app; the browser locates the app then runs it inside that specific iframe on the user’s page. From the user’s perspective this doesn’t look much different, but it gives developers a bit more flexibility in the way they code their apps.
What about Facebook Connect?
Facebook Connect is a special kind of Facebook app because you don’t have to be on the Facebook site to use it as you do with other apps. The Chili’s Create-A-Pepper site is a good example: The site works and it doesn’t have to be connected directly to Facebook. But the app becomes still more functional when the user clicks the “Connect with Facebook” button. Then the Facebook Connect app works more like an application that is hosted within the Facebook site. When users are “connected” they are able to do things like post peppers on their walls and invite friends to use the Create-A-Pepper site. A Facebook Connect website has the capability of interacting with other users on Facebook in the same way that a normal Facebook app does.
Now Go Make Your Own App!
So a Facebook app works pretty much the way a regular website does, except rather than interact with the app on a standalone site, you’re using it within the Facebook site, right on your home page! Developers who create Facebook apps are simply going through the same process they use to make any new website. If you think you’ve got a good idea for an app on Facebook, why not give developing a try?
