CODEWITHSUNDEEP
firebasexamlxamarinxamarin.formsxamarin.ios
Russ J
Russ J

Reputation: 838

Modify Xamarin.Forms page from Xamarin.iOS file

I'm working on a Xamarin.Forms app that uses Firebase Authentication. In order to make Firebase work, I have to create two different platform-specific files (iOS and Android) to process the Authentication tasks (like CreateNewUser and Login). I have a Xamarin.Forms page called "Payment Page" that asks a user to enter their e-mail and password, and submitting this page triggers the DependencyService to create the user account. On the Payment Page, I also have a small window that will appear if something goes wrong with the account creation process (specifically in this case, if a duplicate e-mail already exists in the Auth database).

My question is, if one of the Dependency files for iOS or Android catches a 'ERROR_EMAIL_ALREADY_IN_USE', how can I set the error dialog on the Payment Page to show (in other words, set its 'isVisible' property to 'true'). I've tried a number of things but so far cannot seem to reference elements in the PaymentPage (a Xamarin.Forms page) from the Xamarin.iOS Authentication page.

My Dependency code is as follows:

public void CreateNewUser(string email, string password, System.Collections.Specialized.NameValueCollection userData) 
{ 
    Auth.DefaultInstance.CreateUser(email, password, HandleAuthDataResultHandler); 
}

async void HandleAuthDataResultHandler(AuthDataResult authResult, Foundation.NSError error) 
{ 
     if(error.UserInfo["error_name"].ToString() == "ERROR_EMAIL_ALREADY_IN_USE") 
    { 
       //What goes here to modify the Xamarin.Forms page?? 
   }
 else { }
}

Upvotes: 0

Views: 128

Answers (2)

Johann Pérez
Johann Pérez

Reputation: 367

MessagingCenter might be a good way to go https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/messaging-center

You can suscribe your viewmodel and post a message from the handler with the result.

Upvotes: 1

Jason
Jason

Reputation: 89129

in your XAML code behind

try {
  // call your dependency service
} catch (Exception ex)
{
  // update the UI
}

then in your DependencyService method, it should throw an exception when an error condition occurs

Upvotes: 1

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