Lifecycle Kotlin Extensions

Several Kotlin extensions for convenient use of ViewModel and LiveData

Download

Add repository to your root build.gradle

repositories {
    jcenter()
}

dependencies {
  implementation 'com.idapgroup:lifecycle-ktx:1.0.3'
}

Usage sample

class ExampleActivity : AppCompatActivity() {

    private lateinit var factory: ViewModelProvider.Factory
    val viewModel: ExampleViewModel by lazyViewModel { factory }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        observe(viewModel.liveData, ::observeLiveData)
    }

    private fun observeLiveData(value: String) {
        // do something with value
    }

}

class ExampleViewModel : ViewModel() {

    val liveData = mutableLiveDataOf("1")

}

SingleLiveEvent

SingleLiveEvent - class that extends MutableLiveData and emits value only once for observer. Multiple observers registered but only one will be notified of changes.

Bonus

For Dagger users added ViewModelProvider.Factory class and @ViewModelKey annotation.