CODEWITHSUNDEEP
androidkotlinkotlin-coroutines
Hyper Space
Hyper Space

Reputation: 11

How I do cancel inside CoroutineScope, and detect the cancellation

Detect cancellation from CoroutineScope

I am trying to detect cancellation from CoroutineScope, but isCancelled property doesn't change when I trying to call cancel method inside CoroutineScope

Method I expected to cancel the Coroutine from ViewModel

fun login() = viewModelScope.launch{
        try{
            repository.login(emailLogin.get()!!, passwordLogin.get()!!)
        }catch (e: AuthenticationHttpErrorException){
            cancel(CancellationException(e.message))
            Toast.makeText(getApplication(),e.message, Toast.LENGTH_SHORT).show()
            Log.e("ERROR LOGIN", e.message)
        }
    }

How I called the login method from Activity

fun submitLogin(view: View){
        val loginResult = authenticationViewModel.login()
        if(loginResult.isCancelled){
            Log.e("LOGIN FAILED", "Login cancelled")
        }else{
            Log.v("LOGIN SUCCESS", "Login success")
        }
    }

I am expecting isCancelled property change to true, when I called cancel method from CoroutineScope and Trigger some code inside if statement

Upvotes: 1

Views: 3060

Answers (2)

apksherlock
apksherlock

Reputation: 8371

You are canceling it on the catch block. Which means that repository.login(emailLogin.get()!!, passwordLogin.get()!!) does not throw any exception. Or if it does, perhaps it is not the AuthenticationHttpErrorException that is being thrown. Just to check the error that is happening, try catching a general Exception and than handle the coroutine the same.So:

catch (e: Exception)

Upvotes: 0

Rene
Rene

Reputation: 6258

launch does start an asynchronous coroutine. Therefore the login-body will run later and you can't access the result directly after the invocation. In your example a simple suspend function may be better.

Upvotes: 1

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