ios - FBLoginView を使用してアプリの高速切り替えを行う前に bool 値を確認する方法

Question

これは簡単なシナリオです。ログイン ボタンを表示する FBLoginView を使用しており、クリックするとアプリケーションが高速に切り替えられますが、アプリが高速に切り替えられる前に利用規約のブール値を確認したいと考えています。このシナリオを達成するために私が見つけることができる方法はありません。

    - (void)loginViewShowingLoggedInUser:(FBLoginView *)loginView {
    // Upon login, transition to the main UI by pushing it onto the navigation stack.

        LGAppDelegate *appDelegate = (LGAppDelegate *)[UIApplication sharedApplication].delegate;
        [self.navigationController pushViewController:((UIViewController *)appDelegate.mainViewController) animated:YES];
}

- (void)acceptTermsAndConditions {

    if (!_checkboxButton.checked) {
        NSString *alertMessage, *alertTitle;
        alertTitle  = @"Terms to Use";
        alertMessage = @"Please accept the terms & condition to use this application.";
        UIAlertView* av = [[UIAlertView alloc] initWithTitle:alertTitle
                                                     message:alertMessage
                                                    delegate:nil
                                           cancelButtonTitle:@"OK"
                                           otherButtonTitles:nil];
        [av show];
        [av release];
    }
}

- (void)loginView:(FBLoginView *)loginView
      handleError:(NSError *)error{
    NSString *alertMessage, *alertTitle;

    // Facebook SDK * error handling *
    // Error handling is an important part of providing a good user experience.
    // Since this sample uses the FBLoginView, this delegate will respond to
    // login failures, or other failures that have closed the session (such
    // as a token becoming invalid). Please see the [- postOpenGraphAction:]
    // and [- requestPermissionAndPost] on `SCViewController` for further
    // error handling on other operations.

    if (error.fberrorShouldNotifyUser) {
        // If the SDK has a message for the user, surface it. This conveniently
        // handles cases like password change or iOS6 app slider state.
        alertTitle = @"Something Went Wrong";
        alertMessage = error.fberrorUserMessage;
    } else if (error.fberrorCategory == FBErrorCategoryAuthenticationReopenSession) {
        // It is important to handle session closures as mentioned. You can inspect
        // the error for more context but this sample generically notifies the user.
        alertTitle = @"Session Error";
        alertMessage = @"Your current session is no longer valid. Please log in again.";
    } else if (error.fberrorCategory == FBErrorCategoryUserCancelled) {
        // The user has cancelled a login. You can inspect the error
        // for more context. For this sample, we will simply ignore it.
        NSLog(@"user cancelled login");
    } else {
        // For simplicity, this sample treats other errors blindly, but you should
        // refer to https://developers.facebook.com/docs/technical-guides/iossdk/errors/ for more information.
        alertTitle  = @"Unknown Error";
        alertMessage = @"Error. Please try again later.";
        NSLog(@"Unexpected error:%@", error);
    }

    if (alertMessage) {
        [[[UIAlertView alloc] initWithTitle:alertTitle
                                    message:alertMessage
                                   delegate:nil
                          cancelButtonTitle:@"OK"
                          otherButtonTitles:nil] show];
    }
}

- (void)loginViewShowingLoggedOutUser:(FBLoginView *)loginView {
    // Facebook SDK * login flow *
    // It is important to always handle session closure because it can happen
    // externally; for example, if the current session's access token becomes
    // invalid. For this sample, we simply pop back to the landing page.
    LGAppDelegate *appDelegate = (LGAppDelegate *)[UIApplication sharedApplication].delegate;
    if (appDelegate.isNavigating) {
        // The delay is for the edge case where a session is immediately closed after
        // logging in and our navigation controller is still animating a push.
        [self performSelector:@selector(logOut) withObject:nil afterDelay:.5];
    } else {
        [self logOut];
    }
}

- (void)logOut {
    [self.navigationController popToRootViewControllerAnimated:YES];
}