Using a BindingAdapter with a string-array in Kotlin

Question

I have the following BindingAdapter:

@BindingAdapter("entries")
fun setEntries(view: Spinner, entries: Array<String>) {
    // Do something
}

And on my XML file:

<Spinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:entries="@{@stringArray/my_string_array}"/>

But when building, I get an error:

e: [kapt] An exception occurred: android.databinding.tool.util.LoggedErrorException: Found data binding errors.
****/ data binding error ****msg:Cannot find the setter for attribute 'app:entries' with parameter type java.lang.String[] on android.widget.Spinner.

I have followed the advice in this question, but what would be the Kotlin equivalent for String[] in this case?

Or, alternatively, can I pass the actual resource id instead of a String array to the Binding Adapter?

Thank you!

Answer 1

Well, the error won't be reproduced with the code provided, because it was in the second parameter, which I omitted naively thinking it was unrelated to the problem.

The actual code was:

@BindingAdapter("entries", "hint", requireAll = false)
fun setHintAdapter(view: Spinner, entries: Array<String>, @StringRes hintRes: Int?) {

    val hint = hintRes?.run {
        try {
            MainAct.i.getString(this)
        } catch (e: Resources.NotFoundException) {
            null
        }
    } ?: ""

    val layout = android.R.layout.simple_spinner_item

    view.adapter = HintAdapter(hint, view.context, layout, entries)
}

And the XML:

<Spinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:entries="@{@stringArray/my_string_array}"
    app:hint="@{@string/some_string}"/>

The error is completely unrelated to app:entries, it's in app:hint. I'm providing a String and expecting an Int (Well, a StringRes).

Changing it to:

@BindingAdapter("entries", "hint", requireAll = false)
fun setHintAdapter(view: Spinner, entries: Array<String>, hint: String) {

    val layout = android.R.layout.simple_spinner_item

    view.adapter = HintAdapter(hint, view.context, layout, entries)
}

Fixes it.