Data Binding in Android – Using ObservableField to Update UI automatically

As I shown in the previous post where we used BaseObservable to update UI when binding object is changed, this post will show you another simple way to achieve this.

Do Check my previous posts for better understanding of DataBinding and methods used in DataBinding.

1. http://www.coderzheaven.com/2017/01/15/simple-databinding-in-android-example/
2. http://www.coderzheaven.com/2017/01/20/data-binding-in-android-using-observables/

Here is another way to do it. In this method we will use ObservableField to update the UI.

We will create a Bindable class named User2 which contains two variables firstName and lastName, both are ObservableFields.

Binding Class

package binding_demo.coderzheaven.com.bindingdemo;

import android.databinding.ObservableField;

public class User2 {

    public final ObservableField<String> firstName = new ObservableField<>();
    public final ObservableField<String> lastName = new ObservableField<>();

}

For this we will make a small change in the layout to add new Binding Class.

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".MainActivity">

    <data>
        <variable
            name="user2"
            type="binding_demo.coderzheaven.com.bindingdemo.User2" />
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{user2.firstName}" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{user2.lastName}" />
			
        <Button
            android:id="@+id/b1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </LinearLayout>

</layout>

Access and Set Data

	// ObservableFields
	user2 = new User2();
	user2.firstName.set("Google");
	user2.lastName.set("Android");
	binding.setUser2(user2);
		

	user2.lastName.get();