Have you ever noticed that for some applications on facebook, they can be added to your user profile page as a tab but some cannot? Besides, there are also "custom-built" pages that appear in someone's user profile.

To enable this feature, you have to enhance your application by developing an application tab. In some cases, this is also referred as "Tabbed Application" (as the tab itself functions like an application).

The most commonly used "Tabbed Application" by Facebook users is of course the "Wall" which is default and mandatory in all user profile pages. The "Wall" is also the default tab that will be displayed when the user profile page is first displayed.

The whole process of developing an application tab is documented and written as an eBook.

There are 2 methods to get the eBook:

 

To highlight, below is the TOC of the book.

  1. Introduction
  2. Registering your Application Tab
  3. Issues to be noted in Designing an Application Tab
    3.1. Application Tab Width
    3.2. Iframe or FBML
    3.3. The meaning of “Each application can only have One Tab”
    3.4. Absolute URLs and Relative URLs behave differently
    3.5. Application Tab being First Displayed in Passive Mode
    3.6. The Viewing User and The Profile Owner
  4. Implementing the “My Friend” Application Tab
    4.1. Registering the Application Tab
    4.2. Page Layout for the “my friends” Tab
    4.3. Coding the “My Friends” Tab
    4.3.1. Getting the Basic Skeleton of “My Friend” Tab
    4.3.2. Displaying Data Specific to the Profile Owner
    4.3.3. Calling the Old REST API
    4.3.4. Calling the Graph API
    4.3.5. Coding the URLs - Relative or Absolute?
    4.3.6. Completed Code for “My Friends” Tab
  5. Working with the Viewing User’s UID and Session Key
    5.1. When do We need to use the Viewing User’s UID and Session Key?
    5.2. When are the Viewing User’s UID and Session Key Available?
  6. Mock AJAX in FBML
    6.1. Example on Using Mock AJAX

 

If you want to test drive this without doing any code changes and development, simply visit my demo app, grant the permission. Then go to the application profile and use the "Add to my page" and select where the application tab should be added to.