CODEWITHSUNDEEP
javaandroidkotlinandroid-roomkotlin-coroutines
Nicole Foster
Nicole Foster

Reputation: 381

Type mismatch error while using a coroutine

I have the following in my viewModel

fun getUsernamePassword(inputUserName:String, inputPassword:String):List<User> = viewModelScope.launch(Dispatchers.IO) {
        return repository.getUsernamePassword(inputUserName, inputPassword)
    }

However, I am getting an error saying Type mismatch. Required: List<User> Found:Job What can I do to solve this error. The ultimate goal is to have the function run on a non-black thread operate and a part from the MAIN THREAD to avoid conflict and errors.

Upvotes: 1

Views: 1351

Answers (1)

noahutz
noahutz

Reputation: 1217

viewModelScope.launch returns a background Job where you perform your actual repo operation. In this case, you may need an Observable or LiveData to store the list of users in which your UI needs to act upon.

You can do something like this in your ViewModel:

val userList = MutableLiveData<List<User>>()

fun getUsernamePassword(inputUserName:String, inputPassword:String) = viewModelScope.launch(Dispatchers.IO) {
    val list = repository.getUsernamePassword(inputUserName, inputPassword)
    userList.postValue(list)
}

In your view, you need to observe to changes to the userList of the ViewModel by:

viewModel.userList.observe(viewLifecycleOwner, {
    // Place UI changes here
})

Upvotes: 1

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