Platform Update: OAuth 2.0 Migration, Open Graph Tags for Video and Audio

Facebook has announced updates to several planned migrations and support for video and audio Open Graph tags in its weekly Platform update to the Developer Blog. Also, as of today, the November 2010 Rollup, POST for Canvas, and JSON Encoding Empty Arrays migrations are enabled by default for new application, and all apps will be required to migrate on March 10, 2011.

OAuth 2.0 for Canvas

To ensure users don’t “trick [an] application into thinking they are someone else”,  when the app calls for the user’s ID, Facebook developed Canvas Authentication OAuth 2.0. It uses a signed_request with an application’s secret which is only known to the developer and Facebook, preventing third parties from altering the signature without invalidating the request. This more secure format helps protect users and developers.

OAuth 2.0 for Canvas is leaving beta without changes, but the migration won’t be forced on developers using fb_sig “for the forseeable future”. However, Facebook recommends migrating to signed_request, as those who don’t won’t receive new features, and fb_sig use will no longer appear in documentation. The old “Canvas Session Parameter” will be removed on March 10, 2011, so those who’ve enabled it should move to OAuth 2.0 for Canvas before then.

Open Graph Tags for Video and Audio

At f8, Facebook began allowing developers to define Open Graph object meta tags to denote an object’s type. This markup helps Facebook properly direct actions taken to an object, such as placing the Like of an object tagged “movie” in the Movies category of a user’s interests. In a Platform update last month, Facebook began allowing objects with less than 10,000 Likes to change their type tag without resetting their Likes.

Now, Facebook is supporting new tag types for audio and video content. Audio or video files on an Open Graph-enabled site tagged og:video or og:audio will be displayed on the full news feed story published if a user Likes with comment the hosting Open Graph page. These rich media feed stories are larger and much more compelling, driving additional Likes to the original Open Graph page. It’s therefore advised that if an Open Graph page hosts a representative video or audio file, it should be be tagged with og:video or og:audio to take advantage of this increased exposure.

App Requests in the Notifications Channel

Also included in the blog post is a mention of the test of application requests and invites in the notifications channel which we covered yesterday. If rolled out, the notifications channel could significantly aid app discovery and retention.