strvcom / android-view-model-binding

A lightweight library aiming to speed up Android app development by leveraging the new Android Data Binding together with the Model-View-ViewModel design pattern.

Android ViewModelBinding

Intro

A lightweight library aiming to speed up Android app development by leveraging the new Android Data Binding together with the Model-View-ViewModel design pattern.

Installation

Gradle/Maven (jcenter)

compile 'cz.kinst.jakub:viewmodelbinding:0.8'

Usage

Activity

MainActivity.java

public class MainActivity extends ViewModelActivity<ActivityMainBinding, MainViewModel> {

	@Override
	public ViewModelBindingConfig getViewModelBindingConfig() {
		return new ViewModelBindingConfig(R.layout.activity_main, MainViewModel.class);
	}
}

activity_main.xml

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

	<data>

		<variable
			name="viewModel"
			type="cz.kinst.jakub.sample.viewmodelbinding.MainViewModel"/>
	</data>

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

		<EditText
			android:id="@+id/name_edit_text"
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:hint="@string/hint_enter_your_name"/>

		<Button
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:onClick="@{viewModel.onClickGreetButton}"
			android:text="Greet"/>

		<TextView
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:gravity="center"
			android:text="@{viewModel.name != null &amp;&amp; !viewModel.name.empty ? @string/hello(viewModel.name) : ``}"
			tools:text="@string/hello"/>
	</LinearLayout>
</layout>

ViewModel

MainViewModel.java

public class MainViewModel extends ViewModel<ActivityMainBinding> {

	public ObservableField<String> name = new ObservableField<>();

	@Override
	public void onViewModelCreated() {
		super.onViewModelCreated();
		// Do API calls etc.
	}

	@Override
	public void onViewAttached(boolean firstAttachment) {
		super.onViewAttached(firstAttachment);
		// manipulate with the view
	}

	public void onClickGreetButton(View v) {
		name.set(getBinding().nameEditText.getText().toString());
	}

	@Override
	public void onViewModelDestroyed() {
		super.onViewModelDestroyed();
		// Cancel API calls
	}
}

Real usage

For a more complex example of using this approach, see Weather 2.0 project.

Android Studio New Screen Template

To deploy new screens even faster, use the included Android Studio Template (revision 2)

Usage

1. Copy the template folder to Android Studio templates folder (/Applications/Android Studio.app/Contents/plugins/android/lib/templates/ on Mac) OR run the following command to download and install the template automatically

    curl -o viewmodelbinding.zip -Lk https://github.com/jakubkinst/Android-ViewModelBinding/archive/master.zip && unzip viewmodelbinding.zip && cp -af Android-ViewModelBinding-master/extras/AndroidStudioTemplate/templates/. "/Applications/Android Studio.app/Contents/plugins/android/lib/templates/" && rm -r Android-ViewModelBinding-master && rm viewmodelbinding.zip
   

2. Restart Android Studio

3. Use File>New>ViewModelBinding>ViewModelBinding Screen action to add a new screen

Changelog

v0.8 (Jan 19, 2016)

• ViewModelConfig can be created without BR.viewModel as long as the name ov the binding variable is viewModel
• Added onViewModelCreated() callback in ViewModel
• BREAKING Renamed onModelRemoved() to onViewModelDestroyed() callback in ViewModel
• Added getResources() convenience method to ViewModel

Authors

• Jakub Kinst ([e-mail])
• Stepan Sanda ([e-mail])

The library was inspired by a great AndroidViewModel library by Inloop

License

Copyright 2015 Jakub Kinst & Stepan Sanda

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.