I am not able to fetch user data from Facebook in iOS

Question

I am new to iPhone programming.Using below code i am login into Facebook and fetching data.But here problem is if click on the Loginwithfacebook button Facebook dialog box opening.there i am enter username and password of Facebook after that if again click on same button then i am getting user data.But i don't want to click on double time.And also once i login in Facebook.inside the app where i want to fetch user data at that time i don't to login one more time until i click on logout.Please give me best idea.

-(void)LoginWithFacebookk:(id)sender
{ 
   if (!FBSession.activeSession.isOpen) {

    FBSession *session = [[FBSession alloc] init];
    // Set the active session
    [FBSession setActiveSession:session];
    // Open the session
    [session openWithBehavior:FBSessionLoginBehaviorForcingWebView
            completionHandler:^(FBSession *session,
                                FBSessionState status,
                                NSError *error)
     {


            }];

        }
        else
        {
            NSLog(@"open response");
            FBRequest* friendsRequest = [FBRequest requestForMe];
            [friendsRequest startWithCompletionHandler: ^(FBRequestConnection *connection,NSDictionary <FBGraphUser> *user,NSError *error) {

                NSString *emailiddd=[NSString stringWithFormat:@"%@",[user objectForKey:@"email"]];

                NSLog(@"%@",emailiddd);
                NSString *post = [NSString stringWithFormat:@"email=%@",emailiddd];

                NSLog(@"%@",post);

     }];
               }
    }
}

Answer 1

if you are checking sample code of provide by Facebook in FacebookSDK there is one sample SessionLoginSampleplease check how did work:-

You have to configur you app like this:-

in Native iOS app you have to set you app Bundle Id that you are using in to you Project for example(com.compame.projecname)

For implement in to your Project Here i put the explain.

in .h file create One Button with IBOutlet and connect this button in to xib as we did normally

#import <FacebookSDK/FacebookSDK.h>


@interface LoginViewController : UIViewController<FBLoginViewDelegate>
{
    IBOutlet UIButton *FB_login; // just connect IBoutlate no need to give IBAction
    FBLoginView *loginview;

}
@property (strong, nonatomic) id<FBGraphUser> loggedInUser;
@property (strong, nonatomic) IBOutlet FBProfilePictureView *profilePic; //this is for show profile pic or logged in user

in .m File @implementation LoginViewController @synthesize profilePic = _profilePic;

- (void)viewDidLoad
{
    loginview = [[FBLoginView alloc] init];
    loginview =
    [[FBLoginView alloc] initWithPublishPermissions:[NSArray arrayWithObjects:@"publish_actions",@"email",nil] defaultAudience:FBSessionDefaultAudienceFriends];

    loginview.frame =FB_login.frame;//CGRectMake(90,149, 280, 55);
    for (id obj in loginview.subviews)
    {
        if ([obj isKindOfClass:[UIButton class]])
        {
            UIButton * loginButton =  obj;

            UIImage *loginImage = [UIImage imageNamed:@"btn_fb_login.png"];
            [loginButton setBackgroundImage:loginImage forState:UIControlStateNormal];
            [loginButton setBackgroundImage:nil forState:UIControlStateSelected];
            [loginButton setBackgroundImage:nil forState:UIControlStateHighlighted];
            [loginButton sizeToFit];
        }
        if ([obj isKindOfClass:[UILabel class]])
        {
            UILabel * loginLabel =  obj;
            loginLabel.text =@""; //@"Log in to facebook";
            loginLabel.textAlignment = NSTextAlignmentCenter;
            loginLabel.frame =CGRectMake(123,149, 280, 55);// CGRectMake(0, 0, 271, 37);
        }
    }

    loginview.delegate = self;

    [self.view addSubview:loginview];

    [super viewDidLoad];

}

-(void)LogOut:(NSNotification *)notif
{
    [self loginViewShowingLoggedOutUser:loginview];
    NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
    for (NSHTTPCookie *each in cookieStorage.cookies) {
        // put a check here to clear cookie url which starts with twitter and then delete it
        [cookieStorage deleteCookie:each];
    }
}

#pragma  mark------ FaceBook Sign In method------------

- (void)loginViewShowingLoggedInUser:(FBLoginView *)loginView {

    NSLog(@"Logged In");


}

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

    NSLog(@"%@",user);
    self.profilePic.profileID = user.id;





}
- (void)loginViewShowingLoggedOutUser:(FBLoginView *)loginView {
    // Called after logout
    NSLog(@"Logged out");

    self.profilePic.profileID = nil;
    [FBSession.activeSession closeAndClearTokenInformation];


}
- (void)loginView:(FBLoginView *)loginView handleError:(NSError *)error {
    // see https://developers.facebook.com/docs/reference/api/errors/ for general guidance on error handling for Facebook API
    // our policy here is to let the login view handle errors, but to log the results
    NSLog(@"FBLoginView encountered an error=%@", error);
}

NOTE:- If you are trying to set Image of logged in user using FBProfilePictureView do not forget add [FBProfilePictureView class]; in to app Delegate like Bellow

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [FBProfilePictureView class];
    // Override point for customization after application launch.
    return YES;
}

Here it is a sample code for you Sample code Facebook log-in with Image

Answer 2

If you are willing to, you can also do it with Parse :

- (IBAction)facebookRegistrationButtonPressed {

        // The permissions requested from the user

        NSArray *permissionsArray = @[@"email", @"user_about_me", @"publish_actions", @"status_update", @"manage_pages", @"publish_stream"];

        // Login PFUser using Facebook
        [PFFacebookUtils logInWithPermissions:permissionsArray block:^(PFUser *user, NSError *error) {
            if (!user) {
                if (!error) {
                    NSLog(@"Uh oh. The user cancelled the Facebook login.");
                } else {
                    NSLog(@"Uh oh. An error occurred: %@", error);
                }
            } else if (user.isNew) {
                NSLog(@"User with facebook signed up and logged in!");
                [self processFacebookRequest];
            } else {
                NSLog(@"User with facebook logged in!");
                [self processFacebookRequest];
            }
        }];
    }

    - (void)processFacebookRequest {
        FBRequest *request = [FBRequest requestForMe];
        // Send request to Facebook
        [request startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
            if (!error) {
                // result is a dictionary with the user's Facebook data
                NSDictionary *userData = (NSDictionary *)result;
                NSString * email = [result objectForKey:@"email"];

                NSString *facebookID = userData[@"id"];
                NSLog(@"facebookID = %@", facebookID);

            } else {
                NSLog(@"error : %@", error.localizedDescription);
            }
        }];
    }