Fetching user details from Facebook in iOS

Question

I'm new to iPhone development. I'm doing an App where the user has 2 login through Facebook, once he submits his credentials and clicks on Sign In button, I have to fetch details like First name, email and gender from Facebook and after fetching the user has to be directed to the Registration page of the app with the details filled and i need this app to be compatible for iPhone 4,4s and 5.

I tried doing this using the Facebook Graph API but couldn't get it, so anyone can help me out.

Thanks in Advance.

Answer 1

You can do this by using following code :

[FBSession openActiveSessionWithReadPermissions:@[@"email",@"user_location",@"user_birthday",@"user_hometown"]
                                   allowLoginUI:YES
                              completionHandler:^(FBSession *session, FBSessionState state, NSError *error) {

                                  switch (state) {
                                      case FBSessionStateOpen:
                                          [[FBRequest requestForMe] startWithCompletionHandler:^(FBRequestConnection *connection, NSDictionary<FBGraphUser> *user, NSError *error) {
                                              if (error) {
                                               NSLog(@"error:%@",error);                                               
                                              }
                                              else
                                              {                                                   
                                                  // retrive user's details at here as shown below
                                                  NSLog(@"FB user first name:%@",user.first_name);
                                                  NSLog(@"FB user last name:%@",user.last_name);
                                                  NSLog(@"FB user birthday:%@",user.birthday);
                                                  NSLog(@"FB user location:%@",user.location);
                                                  NSLog(@"FB user username:%@",user.username);
                                                  NSLog(@"FB user gender:%@",[user objectForKey:@"gender"]);
                                                  NSLog(@"email id:%@",[user objectForKey:@"email"]);
                                                  NSLog(@"location:%@", [NSString stringWithFormat:@"Location: %@\n\n",
                                                                         user.location[@"name"]]);

                                              }
                                          }];
                                          break;

                                      case FBSessionStateClosed:
                                      case FBSessionStateClosedLoginFailed:
                                          [FBSession.activeSession closeAndClearTokenInformation];
                                          break;

                                      default:
                                          break;
                                  }

                              } ];

and don't forgot to import FacebookSDK/FacebookSDK.h in your code.

EDIT : Update for Facebook SDK v4 (23 April,2015)

Now, Faceboook have released new SDK with major changes. In which FBSession class is deprecated. So all users are suggested to migrate to new sdk and APIs.

Below I have mentioned, how we can get user details via Facebook SDK v4 :

if ([FBSDKAccessToken currentAccessToken]) {
[[[FBSDKGraphRequest alloc] initWithGraphPath:@"me" parameters:nil]
startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
  if (!error) {
     NSLog(@”fetched user:%@”, result);
  }
 }];
}

But before fetching user details, we have to integrate new Facebook login in our code as described in Documentation here.

Here is the Changelog for SDK v4. I suggest going through it for being updated.

Answer 2

Add info.plist file:

  - (IBAction)btn_fb:(id)sender
    {
      if (!FBSession.activeSession.isOpen)
            {
                NSArray *_fbPermissions =    @[@"email",@"publish_actions",@"public_profile",@"user_hometown",@"user_birthday",@"user_about_me",@"user_friends",@"user_photos",];

        [FBSession openActiveSessionWithReadPermissions:_fbPermissions allowLoginUI:YES completionHandler:^(FBSession *session,FBSessionState state, NSError *error)
         {
             if (error)
             {
                 UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Error" message:error.localizedDescription delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                 [alertView show];
             }
             else if(session.isOpen)
             {
                 [self btn_fb:sender];
             }


         }];


        return;
    }


    [FBRequestConnection startWithGraphPath:@"me" parameters:[NSDictionary dictionaryWithObject:@"cover,picture.type(large),id,name,first_name,last_name,gender,birthday,email,location,hometown,bio,photos" forKey:@"fields"] HTTPMethod:@"GET" completionHandler:^(FBRequestConnection *connection, id result, NSError *error)
     {
         {
             if (!error)
             {
                 if ([result isKindOfClass:[NSDictionary class]])
                 {
                     NSLog(@"%@",result);

                 }
             }
         }
     }];
}