Live Event

This library holds a class to handle single live events in Android MVVM architectural pattern. This class is extended form LiveData class, from androidx.lifecycle:lifecycle-extensions library, to propagate the data as an event, which means it emits data just once, not after configuration changes again. Note that event will only be sent to active observers, any observers that started observing after the emit won't be notified of the event.

Usage

This source has a sample app where you can find LiveEventViewModel in it, in which the LiveEvent class is used as follows.

class LiveEventViewModel : ViewModel() {
    private val clickedState = LiveEvent<String>()
    val state: LiveData<String> = clickedState

    fun clicked() {
        clickedState.value = ...
    }
}

LiveEventConfig

There are two behaviours of LiveEvent in-demand. First one is LiveEventConfig.Normal, where supports multi-observers on all cases the same. This config was originally implemented for this library so it's the default config, but if you want to be explicit, you can pass it to the constructor of LiveEvent.

The second config is LiveEventConfig.PreferFirstObserver. This one is useful when you want to emit an event in the init method of ViewModel and expect the first observer receive it. To set it up you need to pass it to the constructor

private val clickedState = LiveEvent<String>(config = LiveEventConfig.PreferFirstObserver)

Download

Download via gradle

implementation "com.github.hadilq:live-event:$libVersion"

where you can find the libVersion in the Releases page of this repository.

Snapshots of the development version are available in Sonatype's snapshots repository.

Contribution

Just create your branch from the master branch, change it, write additional tests, satisfy all tests, create your pull request, thank you, you're awesome.