title: Check Facebook Permissions on iOS
body: <p>I've seen <a href="https://stackoverflow.com/questions/8848564/ios-facebook-sdk-check-permissions">this post</a> which describes how to use the graph api to check a user's permissions, however I'm not sure how to actually check a specific permission. </p>
  
  <p>Calling <code>[facebook requestWithGraphPath:@"me/permissions" andDelegate:self];</code> calls the delegate method - <code>(void)request:(FBRequest *)request didLoad:(id)result</code> but how best to handle the response? I already have two blocks in this delegate which handle other types of requests, specifically by calling <code>if ([result isKindOfClass:[NSArray class]])</code> and <code>if ([result isKindOfClass:[NSDictionary class]])</code> Presumably the FBRequest for permissions is also an Array, so how can I distinguish it from other FBRequest arrays? And once I have the array, how do I check a specific permission - in my case publish_stream. </p>
  
  <p>Also, is this the quickest way to do it? I want to check if this permission is active and if not, prompt the user to log in again. Currently I check if the session needs validating by calling <code>if (![facebook isSessionValid])</code> so I could change this to something like <code>if (![facebook isSessionValid] || ![self checkPermissions]</code> but this would require a full request call.</p>