Equivalent of loginViewShowingLoggedInUser

Question

I am trying to migrate my app from Facebook SDK 3.4 to 4.x. I used the following import

   #import <FBSDKCoreKit/FBSDKCoreKit.h>
   #import <FBSDKLoginKit/FBSDKLoginKit.h>
   #import <FBSDKLoginKit/FBSDKLoginButton.h>

I used to have two methods

- (void)loginViewShowingLoggedInUser:(FBLoginView *)loginView

- (void)loginViewFetchedUserInfo:(FBLoginView *)loginView user:(id<FBGraphUser>)user

I can't find these methods in 4.x SDK.

I can see FBLoginView changed to FBSDKLoginButtonDelegate. But what is the equivalent of above two methods. I tried looking at Facebook iOS samples but could not figure it out.

Answer 1

There's a method called loginButton:didCompleteWithResult:error: defined in FBSDKLoginButtonDelegate :

- (void) loginButton:(FBSDKLoginButton *)loginButton
didCompleteWithResult: (FBSDKLoginManagerLoginResult *)result
               error: (NSError *)error;

Source : Facebook SDK Docs

Note : The above delegate is only for a login button, ie the delegate will be called only when the user performs a login using the login button. So this delegate will not get called every time the app is launched like loginViewShowingLoggedInUser: used to do.

You have to use FBSDKLoginManager to check if user is aleady logged in :

FBSDKLoginManager works directly with [FBSDKAccessToken currentAccessToken] and sets the currentAccessToken upon successful authorizations (or sets nil in case of logOut).

You should check [FBSDKAccessToken currentAccessToken] before calling logIn* to see if there is a cached token available (typically in your viewDidLoad ).

As for retrieving user info, the new SDK does not automatically fetch user info. inside you login success handler, you have to make a graph request :

NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
[parameters setValue:@"id,name,email,gender" forKey:@"fields"];
[[[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:parameters]
 startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
     if (!error) {
         NSString *userID = [[FBSDKAccessToken currentAccessToken] userID];
         NSString *userName = [result valueForKey:@"name"];
         NSString *emailid=[result valueForKey:@"email"];
         NSString *gender=[result valueForKey:@"gender"];
         NSString *userImageURL = [NSString stringWithFormat:@"https://graph.facebook.com/%@/picture?type=large", [[FBSDKAccessToken currentAccessToken] userID]];
     }
     else{
         NSLog(@"%@",error.localizedDescription);
     }
}];