How can firebase phone auth be implemented in view model?

Question

I'm trying to add the Firebase Phone Authentication code inside a View Model using Kotlin. The problem is that the PhoneAuthProvider requires an activity. Does anyone know how can this code be implemented inside a View Model without the need of an activity?

Thanks!

val mCallbacks: PhoneAuthProvider.OnVerificationStateChangedCallbacks ...

val options = PhoneAuthOptions.newBuilder(auth).apply {
  setPhoneNumber(phoneNumber)
  setTimeout(120L, TimeUnit.SECONDS)
  setActivity(this) <-------------------------- // Activity (for callback binding)
  setCallbacks(mCallbacks)
}.build()
PhoneAuthProvider.verifyPhoneNumber(options)

score 2 · Accepted Answer · answered Jan 18 '21 at 09:42

2

It turned out to be an intentional change in API 20 (check out this issue on Github), even though it violates the MVVM architecture. The reason an activity is needed is that the method falls back to reCAPTCHA. The right way to achieve it is "yet to be determined".

answered Jan 18 '21 at 09:42

Toufic Batache

762
10
24

Which of the two "evils" did you end up opting for, activity instance in the viewmodel or doing everything directly in the fragment/activity? – Nathany Attipoe Jun 06 '21 at 00:57
1

Couldn't agree more, they're both evil. But nope, never activity instance in the viewmodel. It's a shame that it still isn't fixed. – Toufic Batache Jun 06 '21 at 09:43
@NathanyAttipoe unfortunately on getting activity instance in the viewModel in my case. – V Surya Kumar Mar 26 '22 at 18:57
My advice would be @TouficBatache 's suggestion. Never activity instance/context in the vm. The latter would the lesser evil imo – Nathany Attipoe Apr 01 '22 at 13:33

score 1 · Answer 2 · answered Jun 22 '21 at 12:04

My approach is to include everything in the viewModel including the callbacks. I then call a function in the viewModel and pass in an activity parameter. see below:

fun verifyPhoneNumber(phoneNumber: String, activity: Activity) {
        _validFullPhoneNumber.value = phoneNumber
        val options = PhoneAuthOptions.newBuilder(mAuth)
            .setPhoneNumber(phoneNumber)       // Phone number to verify
            .setTimeout(60L, TimeUnit.SECONDS) // Timeout and unit
            .setActivity(activity)
            .setCallbacks(callbacks)          // OnVerificationStateChangedCallbacks
            .build()
        PhoneAuthProvider.verifyPhoneNumber(options)
    }

and in the UI controller, in my case a fragment I call it as:

viewModel.verifyPhoneNumber(validatedPhoneNumber, requireActivity())

same with resend button function.

viewModel:

fun resendVerificationCode(activity: Activity) {
        val options =
            PhoneAuthOptions.newBuilder(mAuth)
                .setPhoneNumber(_validFullPhoneNumber.value!!) // Phone number to verify
                .setTimeout(60L, TimeUnit.SECONDS) // Timeout and unit
                .setActivity(activity)
                .setCallbacks(callbacks) // OnVerificationStateChangedCallbacks
                .setForceResendingToken(_resendToken) // ForceResendingToken from callbacks
                .build()

        PhoneAuthProvider.verifyPhoneNumber(options)
        _isVerificationCodeExpired.value = false
    }

UI controller(fragment):

 viewModel.resendVerificationCode(requireActivity())

How can firebase phone auth be implemented in view model?

2 Answers2