Google Plus Sign in iOS using UIWebView

Question

I am using google+ sign in my app using the Google Plus SDK. When the user taps on the sign in button the user gets redirected to safari. (Standard Process).

However

Answer 1

I tried merging sample apps for Gmail API and GooglePlus to use UIWebView login instead of Safari and it seems to work:

1. create google project BUT when setting up credentials Installed application type choose Other
2. add/enable Google+ API to your google project
3. add/enable Gmail API to google project
4. follow Google+ instructions and add all frameworks and drag ONE BY ONE GoogleOpenSource.framework, GooglePlus.framework and GooglePlus.bundle (you may not need this since we are not using SignInButton, well just in case it is there) in your project
5. add other linker flags -all_load -ObjC, disable ARC
6. DRAG GTMOAuth2ViewTouch.xib into your project files (from OAuth2)

my viewcontroller .h file I added 2 buttons to login and retrieve data, textview to display retrieved data, connected them in the builder. ALSO added interface and property for GTMOAuth2Authentication:

#import <UIKit/UIKit.h>
#import <GoogleOpenSource/GoogleOpenSource.h>
#import <GooglePlus/GooglePlus.h>

@interface MyViewController : UIViewController{
IBOutlet UIButton *loginBttn;
IBOutlet UIButton *retriveBttn;
IBOutlet UITextView *profileTextView;

GTMOAuth2Authentication *mAuth;
}

@property (retain, nonatomic) IBOutlet UIButton *loginBttn;
@property (retain, nonatomic) IBOutlet UIButton *retriveBttn;
@property (nonatomic, retain) IBOutlet UITextView *profileTextView;

@property (nonatomic, retain) GTMOAuth2Authentication *auth;

-(IBAction)dologin;
-(IBAction)doretrive;

@end

my viewcontroller .m file:

#import "MyViewController.h"
#import "AppDelegate.h"
#import <GoogleOpenSource/GoogleOpenSource.h>
#import <GooglePlus/GooglePlus.h>

static NSString *const kKeychainItemName = @"Google OAuth2 For gglplustest";
static NSString *const kClientID = @"your client id";
static NSString *const kClientSecret = @"your client secret";

@interface MyViewController ()
@end

@implementation MyViewController
@synthesize loginBttn,retriveBttn;
@synthesize auth = mAuth;
@synthesize profileTextView;

-(IBAction)doretrive{
    GTLServicePlus* plusService = [[[GTLServicePlus alloc] init] autorelease];
    plusService.retryEnabled = YES;

    [plusService setAuthorizer:self.auth];//!!!here use our authentication object!!!

    GTLQueryPlus *query = [GTLQueryPlus queryForPeopleGetWithUserId:@"me"];

    [plusService executeQuery:query
            completionHandler:^(GTLServiceTicket *ticket,
                                GTLPlusPerson *person,
                                NSError *error) {
                if (error) {
                    GTMLoggerError(@"Error: %@", error);
                } else {
                    // Retrieve the display name and "about me" text
                    [person retain];
                    NSString *description = [NSString stringWithFormat:
                                             @"%@\n%@\n%@", person.displayName,
                                             person.aboutMe,person.emails];
                    [profileTextView setText:description];
                }
            }];
}

- (void)auth:(GTMOAuth2Authentication *)auth finishedRefreshWithFetcher:(GTMHTTPFetcher *)fetcher error:(NSError *)error {
    [self viewController:nil finishedWithAuth:auth error:error];
     if (error != nil) {
     // Refresh failed
         NSLog(@"Authentication Error %@", error.localizedDescription);
         self.auth=nil;
         return;
     }
     self.auth=auth;
}

- (void)viewController:(GTMOAuth2ViewControllerTouch *)viewController finishedWithAuth:(GTMOAuth2Authentication *)auth error:(NSError *)error
{
    if (error != nil) {
        // Authentication failed
        NSLog(@"Authentication Error %@", error.localizedDescription);
        self.auth=nil;
        return;
    }
    self.auth=auth;
    [viewController release];//no ARC
}

-(IBAction)dologin{
    NSString *scope = kGTLAuthScopePlusLogin;//Google+ scope
    GTMOAuth2Authentication * auth = [GTMOAuth2ViewControllerTouch 
    authForGoogleFromKeychainForName:kKeychainItemName
    clientID:kClientID
    clientSecret:kClientSecret];
    if ([auth refreshToken] == nil) {
        GTMOAuth2ViewControllerTouch *authController;
        authController = [[GTMOAuth2ViewControllerTouch alloc] 
        initWithScope:scope 
        clientID:kClientID 
        clientSecret:kClientSecret  
        keychainItemName:kKeychainItemName
        delegate:self
        finishedSelector:@selector(viewController:finishedWithAuth:error:)];
        [[self navigationController] pushViewController:authController animated:YES];
    }else{
        [auth beginTokenFetchWithDelegate:self didFinishSelector:@selector(auth:finishedRefreshWithFetcher:error:)];
    }
}

- (void)viewDidLoad {
    [super viewDidLoad];
}

So now, when view is loaded it does not try to login.

Then on a view when I touch loginBttn that will run dologin method (from GmailMail sample) where I setup the scope to GooglePlus: 1st it will check if there is saved info in keychain, if it is, it will proceed without asking you to login. If not, it will do it as for Gmail login in UIWebView directly inside my app.

here how it looks after login:

Then I can touch retriveBttn to run retrieve method (e.g. to get Name, About and emails) that uses GooglePlus sample HOWEVER I set Authorizer to the authenticator that I saved after successful login like that: [plusService setAuthorizer:self.auth];

here is the view before and after retrieve is complete:

Seems like it is doing what is is supposed to.

Answer 2

Update

Google has released a new iOS SDK that does supports WebView Sign In, among several other updates and features. (Thanks to John Hjelmstad and Co for working on this)

Original Post

I recommend strongly against using the outdated GTMAuth2Controller. If you really want this feature please add your voice to the official Google thread. The more voices we add there the higher the chance that Google will introduce this feature. Currently Apple are rejecting all Apps that force the user to flip flop from Safari to your App for Google+ Sign In. Even though Apple are aware that this is how Googles SDK does this (Nevermind the fact that Facebook does the same but won't get your app rejected).

Its petty and lame but unfortunately all we can do is appeal to Google to add support for this.

Here's what Google had to say about this issue (I also protested the use of their outdated controller)

Hi all -- at Google, we aim to make our services available to as many users and developers as possible. We have heard a very small number of reports of problems of this type, but those app developers appear to have eventually gotten approval to launch by working through Apple’s standard process.

Meantime, we're continuing to work on improved mechanisms for login. I do agree with Daniel that direct use of GTMOauth2ViewControllerTouch, or the equivalent UIWebView trickery, is not recommended. Oct 16, 2014

Answer 3

To resolve this problem you can use Google libs. It's has a G+ SDK inside and has GTMAuth2ControllerTouch, which provides you sign into all Google service. Look here how to get this library and here is an example how to use it. It's very easy. Also you can find some videos on YouTube, which describes how to install this library.

You can use this library with Google+ SDK, but you need to do some work to merge this 2 APIs.