A command is an Observable triggered in response to some action, typicallyUI-related.
It manage the extra states, such as loading, enabled, errors for you, when using RxJava2 implement the functions of your ViewModel.
ViewModel
public class MyViewModel extends ViewModel {
public final RxCommand<List<User>> usersCommand;
public MyViewModel(final UserRepository userRepository) {
usersCommand = RxCommand.create(o -> {
return userRepository.getUsers();
});
}
}Activity
public class MyActivity extends AppCompatActivity {
public void onCreate(Bundle savedInstanceState) {
MyViewModel viewModel = ViewModelProviders.of(this).get(MyViewModel.class);
viewModel.usersCommand
.switchToLatest()
.observeOn(AndroidSchedulers.mainThread())
.compose(Live.bindLifecycle(this))
.subscribe(users -> {
// update UI
});
viewModel.usersCommand
.executing()
.compose(Live.bindLifecycle(this))
.subscribe(executing -> {
// show or hide loading
})
viewModel.usersCommand
.errors()
.compose(Live.bindLifecycle(this))
.subscribe(throwable -> {
// show error message
});
}
}buildscript {
repositories {
jcenter()
maven { url 'https://maven.google.com' }
}
}dependencies {
// using Support Library 26.1+
compile 'com.android.support:appcompat-v7:26.1.0'
compile 'com.android.support:support-v4:26.1.0'
compile 'com.android.support:design:26.1.0'
// RxJava
compile 'io.reactivex.rxjava2:rxjava:2.1.0'
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
// Live
compile 'com.shundaojia:live:1.0.2'
// RxCommand
compile 'com.shundaojia:rxcommand:1.2.2'
compile 'android.arch.lifecycle:extensions:1.0.0' // for ViewModel
}