How to set Android DataBinding in nested layouts

Question

I was just reading about data binding feature in android. I was trying to bind a view from a nested layout. My activity is android's default template of DrawerMenuActivity and it has content_my_activity layout nested inside activity_my_activity layout.

I have 3 auto generated binding classes. MyActivityBinding, AppBarMyActivityBinding and ContentMyActivityBinding.

I tried initialising all 3 class as below:

MyActivity.java

MyActivityBinding activityBinding;
AppBarMyActivityBinding appBarBinding;
ContentMyActivityBinding contentBinding;

protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);

    activityBinding = DataBindingUtils.setContentView(this, 
                               R.layout.activity_my_activity);
    appBarBinding = DataBindingUtils.setContentView(this, 
                               R.layout.app_bar_my_activity);
    contentBinding = DataBindingUtils.setContentView(this, 
                               R.layout.content_my_activity);

    setName();
}

private void setName(){
    contentBinding.setFirstName("Omkar");
}

But it throws RuntimeException as below:

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example, PID: 18305
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.userInterface.activity.MyActivity}: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
    at android.app.ActivityThread.access$900(ActivityThread.java:154)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:148)
    at android.app.ActivityThread.main(ActivityThread.java:5443)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
 Caused by: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
    at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
    at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
    at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
    at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
    at android.app.Activity.performCreate(Activity.java:6259)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) 
    at android.app.ActivityThread.access$900(ActivityThread.java:154) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:148) 
    at android.app.ActivityThread.main(ActivityThread.java:5443) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 
 Caused by: android.view.InflateException: Binary XML file line #27: Error inflating class fragment
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:782)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
    at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:831)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:423) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:374) 
    at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280) 
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140) 
    at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276) 
    at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88) 
    at android.app.Activity.performCreate(Activity.java:6259) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) 
    at android.app.ActivityThread.access$900(ActivityThread.java:154) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:148) 
    at android.app.ActivityThread.main(ActivityThread.java:5443) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 
 Caused by: java.lang.IllegalArgumentException: Binary XML file line #27: Duplicate id 0x7f0e0081, tag null, or parent id 0xffffffff with another fragment for com.google.android.gms.maps.SupportMapFragment
    at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2416)
    at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
    at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:374)
    at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33)
    at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:75)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:754)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704) 
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:835) 
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798) 
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:838) 
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798) 
    at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971) 
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:831) 
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:515) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:423) 
    at android.view.LayoutInflater.inflate(LayoutInflater.java:374) 
    at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280) 
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140) 
    at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276) 
    at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88) 
    at android.app.Activity.performCreate(Activity.java:6259) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) 
    at android.app.ActivityThread.access$900(ActivityThread.java:154) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:148) 
    at android.app.ActivityThread.main(ActivityThread.java:5443) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 

How do I bind view from content_my_activity in MyActivity.java class, any help is appreciated.

Thanks.

Answer 1

DataBindingUtils.setContentView() does exactly how it is named: It sets the current view to the given parameter. I don't think you want your AppBar as the whole view, or do you?

Nevertheless, I assume that you include your layouts in your layout_activity_main.xml. George Mount has written a whole blog post about this feature. The code examples are from this post.

The first example would be your layout_activity_main.xml (Or however you have named it), where you include your AppBar, your Content and so on.

hello_world.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

        <TextView
                android:id="@+id/hello"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
        <include
                android:id="@+id/world1"
                layout="@layout/included_layout"/>
        <include
                android:id="@+id/world2"
                layout="@layout/included_layout"/>
    </LinearLayout>
</layout>


included_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/world"/>
</layout>

Now that the used layouts are clear, you'll need to jump into your ActivityMain, initialize the DataBinding and access your fields:

//This works if you have used a variable in your <data> tag and you have built your project afterwards, if you don't have an activity
HelloWorldBinding binding = HelloWorldBinding.inflate(getLayoutInflater());

 //if you have an activity, you can use setContentView from the DataBindingUtils. Don't forget to delete the generic setContentView
HelloWorldBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_my_activity);


//Once you have accomplished the above, you can access your data-bound fields like this:
binding.hello.setText(“Hello”);
binding.world1.world.setText(“First World”);
binding.world2.world.setText(“Second World”);

It is important to set Ids to your <include> tags to access them correctly i your Activity.

Answer 2

One can pass the objects in XML ... the xmlns:bind namespace is required (similar to xmlns:app).

<?xml version="1.0" encoding="utf-8"?>
<layout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:bind="http://schemas.android.com/apk/res-auto">
    
   <data>
       <variable name="user" type="com.example.User"/>
   </data>

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

       <include
           layout="@layout/name"
           bind:user="@{user}"/>

       <include
           layout="@layout/contact"
           bind:user="@{user}"/>

   </LinearLayout>

</layout>

source of the example: Layouts and binding expressions.