Two-Way Data Binding: View is missing user defined type

Today I found out about the very-recently-introduced two-way data binding capability in the Android Studio preview, and decided to give it a try.

I have a very simple layout (code below), for composing and sending messages. What I was trying to achieve is having the button "disabled" (and in the future, have some different image accordingly) when there is no text entered in the field.

<?xml version="1.0" encoding="utf-8"?>
<layout
    xmlns:android="http://schemas.android.com/apk/res/android">
<data>
    <variable name="msg" type="String"/>
</data>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <EditText
        android:id="@+id/new_message_input"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:paddingStart="10dp"
        android:hint="@string/hint_compose_message"
        android:inputType="textAutoCorrect|textMultiLine"
        android:text="@={msg}"/>
    <ImageButton
        android:id="@+id/btn_send_message"
        android:layout_width="50dp"
        android:layout_height="match_parent"
        android:src="@drawable/ic_send"
        android:enabled="@{!new_message_input.text.isEmpty()}"
        android:clickable="@{!new_message_input.text.isEmpty()}"/>
</LinearLayout>
</layout>

The example code in the first link shows that something like this should be enough:

<layout ...>
  <data>
    <import type="android.view.View"/>
  </data>
  <RelativeLayout ...>
    <CheckBox android:id="@+id/seeAds" .../>
    <ImageView android:visibility="@{seeAds.checked ? View.VISIBLE : View.GONE}" .../>
  </RelativeLayout>
</layout>

However, when trying to implement similar logic for the enabled/clickable properties of the ImageButton, I am getting the following error:

Error:java.lang.RuntimeException: java.lang.RuntimeException: Found data binding errors. ****/ data binding error ****msg:Identifiers must have user defined types from the XML file. new_message_input is missing it

The problem is definitely with these two lines, since removing them allows the binding class to be properly created.

My questions are:

What am I doing wrong?
How can I resolve this?

I also tried doing it a bit differently, but the result was the same:

<?xml version="1.0" encoding="utf-8"?>
<layout>
<data>
    <import type="android.widget.EditText"/>
    ...
</data>
<LinearLayout
  ...
  <ImageButton
    ...
    android:enabled="@{!(((EditText)new_message_input).getText().toString().isEmpty())}"
    android:clickable="@{!(((EditText)new_message_input).getText().toString().isEmpty())}"/>

Two-Way Data Binding: View is missing user defined type

1 Answers