I have been playing with the Facebook iOS API the past days and I got some questions. If I have two distinct view controllers that both need to use the Facebook object how should I share the object? And is it necessary to share it at all? I have been thinking of making a singleton. What I thought of doing was making a class “SocialMedia” that has a class method named “sharedFacebook”.
Then I have another class named PREFIXFacebook where I conform to the session protocol and make an object. This class has an attribute named facebook. Then I instantiate this class in the SocialMedia class and send the method “facebook” to it and assign the returned object to the static Facebook variable in SocialMedia. Is that bad design? I have not been doing much singletons before, and I don’t even know if it is necessary, but I don’t want to duplicate the code.
Another approach would be to do this in the app delegate, but I read a post here on stack overflow and heard in one of the stanford iOS videos that it is bad to do such things with the global. Any thoughts?
As with most things, global variables are not bad in moderation. If you abuse them, you will be running short on Memory, but I think it is justified in this case. A singleton is essentially a global variable and I believe your plan here is a good one. Not only will it help you with Facebook, but it will help with other single-login sites such as Twitter and Google+.
To keep things with a small footprint, you don’t want to store a million things in the Singleton class. Try to only store the bare minimum needed to avoid re-authenticating. This probably means only the Facebook object itself, and not an additional wrapper class for it.