FBML Essentials

Authorization Tags

Each of the following tags verify in some way the permissions for a user’s role on Facebook. These tags can be quite useful for virally promoting your app. For instance, if you want to encourage non-app users to install your app, use the <fb:visible-to-added-app-users/> tag in your application’s profile box to provide a message that encourages non-app users to add your application. Or, if you want to provide an admin interface that allows the owner of an app or the admin of a page to administer settings within your app, use the <fb:if-is-user/> tag with a uid of profileowner, and only the user who added your app will have access to those settings.

In this section, we will define the specifications of each authorization-related FBML tag on Facebook. The first half of the tags render only on a user’s canvas page or on a canvas page for a Facebook Page. The second half of the tags render only on a user’s profile or on a Facebook Page; they will not render on a canvas page. Each section in this chapter includes a brief description of the tag, followed by required and optional attributes that can be passed to the tags, as well as examples of how those tags can be used.

The “User” Authorization Tag

Authorizing by User Agent

Canvas Page Authorization Tags

It’s important to note that most of the canvas page authorization tags listed in this section are compatible with the <fb:else/> tag.

Profile and Facebook Page Authorization Tags

The user’s profile is the most visited part ...