Back in November, I started blogging about some ideas I was having for standardizing and advancing the ways URL schemas are utilized to communicate between apps on iOS. I got encouragement and good direction from some other developers — particularly Instapaper’s Marco Arment, who had clearly also been putting some thought into the topic.
Those ideas have formed into the x-callback-url protocol. I’ve put together a site to house the spec, and I hope that the site will also become a hub for information and documentation for apps supporting the protocol. From the spec:
The goal of the x-callback-url specification is to provide a standardized means for iOS developers to expose and document the methods they make available to other apps. Using x-callback-url’s source apps can launch other apps passing data and context information, and also provide parameters instructing the target app to return data and control back to the source app after executing an action.’
The current releases of Terminology for both iPad and iPhone are also the first apps to implement x-callback-url method. Full developer documentation is available, but I also put together a screencast as an introduction to some of the things you can do with x-callback-url.