Question

I used to develop a few FB apps in the past (using the old rest-ased api), and now I’m considering to make them actually usable again by porting them to the new 3.1 API.

Sounds nice, but for some reason this is way harder than I should be…

So here are few questions:

• Is there any example of a canvas app using the 3.1 API? Google did not give me anything useful
• Is there still a difference between iframe and FMBL canvas applications? In my app settings, I checked the fmbl-option, but when I’m back at the app overview page, it still says it’s an iframe app.
• The SDK mentions the getUser() function to get the user-id, but how do I request the necessary permissions for my app? When I do some googling, I find even another solution which calls a specific url and then performs a callback. This solution however doesn’t seem to php sdk at all!
• Where is the documentation of the php-api? The only usable thing I find is this: https://github.com/facebook/php-sdk which consists only a few lines of code. And I suspect this is for having a fb login-button on your own website, not for a canvas app.

Answer 1

Firstly, good luck, and best wishes – you’ll need it. Maintaining Facebook apps is way harder than it should be, because Facebook doesn’t believe in legacy support, changes things all the time, and deprecates things quickly and completely. As a (former) Facebook app dev myself, I can tell you there is only one constant: apps will die if you leave them alone. As an app developer, Facebook owes you no favors, and it is vicious when it comes to breaking apps.

As for specifics: as of June 2012, Facebook has deprecated and removed FBML and the REST API, and there is no longer any difference between canvas apps and iFrame apps. This isn’t a soft, “you shouldn’t use it” deprecation – it’s a hard, “your apps are now broken” deprecation. All apps are now iFrame apps, as there is no longer any other way to build them. The docs on how to build a canvas/iFrame app are here, and there’s an auth migration guide that may be helpful in conversion. Oh, and you’ll need to get your app running on HTTPS too, if you haven’t already.

As for the rest of it, it sucks, but the only way you’re really going to be able to maintain and get your application working is using the Open Graph API. Using the PHP SDK, you just run $facebook->api('/graph/url/here') – for instance, to get user information, run $facebook->api("/$userid"). You get the URLs off of the Open Graph docs – just grab everything after the graph.facebook.com bit and pass it to api(). It’s another learning curve, and (depending on the complexity/modularity of your code) is anywhere from a lot to a nightmarish mountain of changes, and there are no drop-in replacements. Sometimes you can use the old REST api, but I doubt that will last very much longer either. It’s painful, but that’s how it goes. You’re at the mercy of Facebook, because it’s their data.

Upgrading apps involves a shift in thinking: apps are now literally just webpages surrounded by the Facebook chrome. There is now no difference between an external website that uses Facebook’s api to pull in information and an app that runs inside of Facebook. It’s for that reason, personally, that I’ve shifted to just that for my own app – an external website that just happens to use Facebook for most of its posting/sharing/user info needs.

For authorization, you request permissions via OAuth, using any number of methods. There are docs on how to do that over on Facebook as well. Specifically for the PHP api, you generate a URL using getLoginURL() and then redirect to it. Facebook eventually redirects back to a URL you specify with info about whether they authorized your app and such, after which you can do a getUser(). If you want fancy/slick/user-friendly popup dialogs without a bunch of redirecting, the Javascript SDK is your friend.