How to get XML's resources in Kotlin code when cannot find context?

Issue

A button's text switchs OK/Canel depends on its onClickListener().

"OK" and "Cancel" was defined in both code and XML, how to define them at one place?

I tried to use btnText.value = application.resources.getString(R.string.cancel).

However, application can only be found inside init{} in viewModel.class.

In viewModel.class:

class xxxViewModel(application: Application, ...

    val btnText = MutableLiveData<String>()

    fun funForListener(){
        if (condition) btnText.value ="OK"
        else btnText.value ="Cancel"

        // error, cannot find application
        btnText.value = application.resources.getString(R.string.cancel)
    }
     
    init{
        // no error
        btnText.value = application.resources.getString(R.string.cancel)
    }

In res/strings.xml:

<string name="cancel">Cancel</string>
<string name="ok">OK</string>

Solution

Your primary constructor is not declaring properties, but just receiving parameters. These can only be used in the init block. Use

class xxxViewModel(val application: Application, ...) 

instead to define an application property in the xxxViewModel class

https://kotlinlang.org/docs/classes.html#constructors

Answered By - derpirscher