如何在Facebook登录iOS应用程序的授权中拒绝电子邮件许可，再次询问电子邮件许可

Question

In my app,there is facebook login am creating custom ui for facebook login.I am fetching users public profile and email.On first time logining in with facebook there is an authorization screen shown as shown in 1.jpg.In this screen there is a option to user which displays edit the info you provide.On clicking that edit button user is directed to next screen where he can deny access for email.My issue is if there is a provision that edit the info you provide button is hidden or is there any possibilty that user is asked for email permission again.

1.jpg

My code is below: *********Appdelegate.h

#import <UIKit/UIKit.h>
#import <FacebookSDK/FacebookSDK.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>


@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) NSString *strBasePath;
-(void)openActiveSessionWithPermissions:(NSArray *)permissions allowLoginUI:(BOOL)allowLoginUI;

@end

******Appdelegate.m


#import "AppDelegate.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.



return YES;
}

-(void)openActiveSessionWithPermissions:(NSArray *)permissions allowLoginUI:(BOOL)allowLoginUI{
[FBSession openActiveSessionWithReadPermissions:permissions
                                   allowLoginUI:allowLoginUI
                              completionHandler:^(FBSession *session, FBSessionState status, NSError *error) {

                                  // Create a NSDictionary object and set the parameter values.
                                  NSDictionary *sessionStateInfo = [[NSDictionary alloc] initWithObjectsAndKeys:
                                                                    session, @"session",
                                                                    [NSNumber numberWithInteger:status], @"state",
                                                                    error, @"error",
                                                                    nil];

                                  // Create a new notification, add the sessionStateInfo dictionary to it and post it.
                                  [[NSNotificationCenter defaultCenter] postNotificationName:@"SessionStateChangeNotification"
                                                                                      object:nil
                                                                                    userInfo:sessionStateInfo];

                              }];
}

-(BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation{
return [FBAppCall handleOpenURL:url sourceApplication:sourceApplication];
}

 - (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

if ([FBSession activeSession].state == FBSessionStateCreatedTokenLoaded) {
    [self openActiveSessionWithPermissions:nil allowLoginUI:NO];
}

[FBAppCall handleDidBecomeActive];

}
#import "ViewController.h"
#import "AppDelegate.h"
#import <QuartzCore/QuartzCore.h>
#import <FacebookSDK/FacebookSDK.h>

@interface ViewController ()

@property (nonatomic, strong) AppDelegate *appDelegate;

-(void)hideUserInfo:(BOOL)shouldHide;

-(void)handleFBSessionStateChangeWithNotification:(NSNotification *)notification;

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];


self.imgProfilePicture.layer.masksToBounds = YES;
self.imgProfilePicture.layer.cornerRadius = 30.0;
self.imgProfilePicture.layer.borderColor = [UIColor whiteColor].CGColor;
self.imgProfilePicture.layer.borderWidth = 1.0;

[self hideUserInfo:YES];
self.activityIndicator.hidden = YES;

self.appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleFBSessionStateChangeWithNotification:) name:@"SessionStateChangeNotification" object:nil];



}

-(void)hideUserInfo:(BOOL)shouldHide{
self.imgProfilePicture.hidden = shouldHide;
self.lblFullname.hidden = shouldHide;
self.lblEmail.hidden = shouldHide;
}

- (IBAction)toggleLoginState:(id)sender {
if ([FBSession activeSession].state != FBSessionStateOpen &&
    [FBSession activeSession].state != FBSessionStateOpenTokenExtended) {

[self.appDelegate openActiveSessionWithPermissions:@[@"public_profile", @"email"] allowLoginUI:YES];


}
else{
    // Close an existing session.
    [[FBSession activeSession] closeAndClearTokenInformation];

    // Update the UI.
    [self hideUserInfo:YES];
    self.lblStatus.hidden = NO;
    self.lblStatus.text = @"You are not logged in.";
  }

  }

 -(void)handleFBSessionStateChangeWithNotification:(NSNotification *)notification{
// Get the session, state and error values from the notification's userInfo dictionary.
NSDictionary *userInfo = [notification userInfo];

FBSessionState sessionState = [[userInfo objectForKey:@"state"] integerValue];
NSError *error = [userInfo objectForKey:@"error"];

self.lblStatus.text = @"Logging you in...";
[self.activityIndicator startAnimating];
self.activityIndicator.hidden = NO;

// Handle the session state.
// Usually, the only interesting states are the opened session, the closed session and the failed login.
if (!error) {
    // In case that there's not any error, then check if the session opened or closed.
    if (sessionState == FBSessionStateOpen) {
        // The session is open. Get the user information and update the UI.
        [FBRequestConnection startWithGraphPath:@"me"
                                     parameters:@{@"fields": @"first_name, last_name, picture.type(normal), email"}
                                     HTTPMethod:@"GET"
                              completionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
                                  if (!error) {

                                      // Set the use full name.
                                      self.lblFullname.text = [NSString stringWithFormat:@"%@ %@",
                                                               [result objectForKey:@"first_name"],
                                                               [result objectForKey:@"last_name"]
                                                               ];

                                      // Set the e-mail address.
                                      self.lblEmail.text = [result objectForKey:@"email"];

                                      // Get the user's profile picture.
                                      NSURL *pictureURL = [NSURL URLWithString:[[[result objectForKey:@"picture"] objectForKey:@"data"] objectForKey:@"url"]];
                                      self.imgProfilePicture.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:pictureURL]];


                                      strFbEmail=[result objectForKey:@"email"];

                                      strFbFirstName=[result objectForKey:@"first_name"];
                                      strFbLastName=[result objectForKey:@"last_name"];
                                      strFbAccessToken = [[[FBSession activeSession] accessTokenData] accessToken];
                                      NSLog(@"%@ -------- %@ -------- %@ -------%@",strFbAccessToken,strFbEmail,strFbFirstName,strFbLastName);

                                      //[self sendFbData];
                                      // Make the user info visible.
                                      [self hideUserInfo:NO];

                                      // Stop the activity indicator from animating and hide the status label.
                                      self.lblStatus.hidden = YES;
                                      [self.activityIndicator stopAnimating];
                                      self.activityIndicator.hidden = YES;
                                  }
                                  else{
                                      NSLog(@"%@", [error localizedDescription]);
                                  }
                              }];

        [self.btnToggleLoginState setTitle:@"Logout" forState:UIControlStateNormal];
    }
    else if (sessionState == FBSessionStateClosed || sessionState == FBSessionStateClosedLoginFailed){
        // A session was closed or the login was failed. Update the UI accordingly.
        [self.btnToggleLoginState setTitle:@"Login" forState:UIControlStateNormal];
        self.lblStatus.text = @"You are not logged in.";
        self.activityIndicator.hidden = YES;
    }
}
else{
    // In case an error has occurred, then just log the error and update the UI accordingly.
    NSLog(@"Error: %@", [error localizedDescription]);
    [self hideUserInfo:YES];        
    [self.btnToggleLoginState setTitle:@"Login" forState:UIControlStateNormal];

}


}

Answer 1

if ([FBSession.activeSession.permissions indexOfObject:@"email"] == NSNotFound) {
    [FBSession.activeSession requestNewReadPermissions:@[@"email"]
                         completionHandler:^(FBSession *session,
                                             NSError *error) 
    {
         // Handle new permissions callback
    }];
} else {
    // permission exists
}

Try this. Hope it helps