How to use the LiveData value in another method of Activity?

user_10131867 0
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I am using MVVM architecture and having a hard time figuring out where to store value observed from LiveData which just needs to be used in if statement in onActivityResult() of the same Activity or any other method.

Suppose, I've this method that observes live data from the viewModel in the Activity.

fun subscribeObservers() {
    myViewModel.liveData.observe(viewLifeCycleOwner, Observer { myLiveDataString ->
        setTextField(myLiveDataString)
    });
}

And I want to use that particular value observed from LiveData in onActivityResult of the same Activity.

Suppose like this,

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        if (requestCode == RC) {
            if (myLiveDataString == "ERROR") {
                showErrorDialogToUser()
            }
        }
    }

So my question is where should I store the data observed from LiveData to check for If statement? Should I just store it in an Activity? Is it a good idea?

android-livedata kotlin mvvm android-activity android
2 Answers

Just use myViewModel.liveData.value to get the value.

Shouldn't liveData value be retrieved only through observer method?

Not only. When observing, you get notified when the value changes. Nothing prevents you from checking the value. LiveData is just a data holder.

user_32903390

If you just mean you want to use the LiveData value within the same Activity then create a private String liveDataReturnValue in your Activity class and assign the returned LiveData value from the Observer


var liveDataReturnedValue : String = "";

fun subscribeObservers() {
    myViewModel.liveData.observe(viewLifeCycleOwner, Observer { myLiveDataString ->
        setTextField(myLiveDataString);
        this@YourActivityClass.liveDataReturnedValue = myLiveDataString;
    });
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (requestCode == RC) {
        if (myLiveDataString == "ERROR") {
            showErrorDialogToUser()
        }
    }
}
user_144184410
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