How to reference a function from xml that is defined in kotlin's constructor?

Question

I'm trying to avoid writing extra lines if possible

This works

class ViewModel(val clicked: () -> Unit){
    fun click(){
        clicked()
    }
}

But I would like to write it like this if possible

class ViewModel(val clicked: () -> Unit)

Xml looks like this

android:onClick="@{() -> viewModel.click()}"
or
android:onClick="@{() -> viewModel.clicked()}"

Writing the shorter version fails with cannot find method clicked()

Bartek Lipinski · Accepted Answer · 2019-08-08 12:18:28Z

1

I believe that with this:

class ViewModel(val clicked: () -> Unit)

Inside your xml, you would have to refer to the invoke method of your lambda.

So something like this:

android:onClick="@{() -> viewModel.clicked.invoke()}"

Edit: or... can't you just use this?

android:onClick="@{viewModel.clicked}"

passing your lambda directly?

answered Aug 8, 2019 at 12:18

Bartek Lipinski

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1 Comment

android:onClick="@{() -> viewModel.clicked.invoke()}" works, thanks