Error in Facebook API Return

Question

Follow my scenario for better understanding:

• I have View Home calling View Login, by pushViewController.
• In my Login View, there is the custom Facebook button that is normally calling the facebook authorization page;
• But the return of the facebook permission screen is causing me problems, instead of it returning to my Login View, is returning to my Home View;

I’m getting the following message in the log: Unbalanced calls to begin/end appearance transitions for <XXX.LoginTableViewController: 0x14eba93d0>.

This is my login action, it won’t stay this way, but I was simplifying the most to try to find the problem:

@IBAction func facebookButton() {
    let login = FBSDKLoginManager()
    login.logInWithReadPermissions(["public_profile", "email"],
                                   fromViewController: self) { (result, error) in

        if error != nil {
            print("deu merda")
        } else if result.isCancelled {
            print("cancelou")
        } else {
            print("login")
        }
    }
}

Note: in the same Login View I have the login button of Twitter, which is working normally.

Answer 1

Unbalanced calls to Begin/end Appearance Transitions for "Logintableviewcontroller"

This error happens because at some point in your code you are making pushViewController more than once at the same time.

For example: You create a button in Storyboard and turn on a segue on that button to another screen, and also creates a method IBAction clickBotao: that calls the other screen too. In that case you will have 2 pushs to the same screen and this causes this error.

Make sure when he returns from Facebook callback he’s not doing something like I explained above.