Facebook Introduces Opt-In Migration for Developers, Single Sign-On for iOS SDK

Facebook has started a new monthly migration system for easing application developers into new features and bug fixes. The opt-in system allows developers to migrate when they’re ready, as each set of changes could require them to alter their apps to prevent them from breaking. Other notes from the weekly Platform update post to the Facebook Developer Blog include the addition of single sign-on to the Facebook iOS SDK, and several bug reports.

The opt-in migration system has the following schedule:

  1. A new migration is introduced, developers can enable it through the Developer application’s Advanced tab
  2. One month after introduction, the migration is enabled by default for newly created applications
  3. Three months after introduction, the migration is enabled for all applications

All deadlines and changes are listed in the migrations section of the Developer Roadmap. The system allows the Facebook Platform to remain a rapidly changing development environment without jeopardizing the stability of applications, or the sanity of developers.

The first migration, known as the “November 2010 Rollup” updates the Graph API for the terminology switch from fans to Likes, puts all Event times on the Coordinated Universal Time standard, and enhances the clarity of network privacy settings in FQL. The specific changes are:

  • Graph API: The fan_count attribute on the Page object will be renamed to likes.
  • Graph API: The likes connection on the Post object will include both the count and the users that have liked the object.
  • Graph API: All id fields returned by POST calls will be typed as strings.
  • Graph API: For events, start_time and end_time will use UTC time rather than in Pacific time.
  • FQL: The networks field in privacy table will be ‘ALL_NETWORKS’ instead of ‘1’ if an object is shared for all of user’s networks.

Facebook announced single sign-on last week as a way to reduce the number of times users have to enter their email address and password on mobile devices. Users type in their credentials to login once, then other Facebook-integrated apps on the device only require a single touch to be authorized.

With the new Facebook iOS SDK, third-party apps are passed the authorization token from the Facebook for iPhone app (version 3.2.3 or later) or the authorization cookie from Safari. Users on older versions of iOS which don’t support multi-tasking will see the old UIWebView login screen each time they open a Facebook-integrated app. This SDK update will especially benefit apps which require Facebook integration, but rely on speedy booting to be useful.