Vita is a light and simple library that helps you to share ViewModel between fragments and even activities! Also you can create ViewModels that are available all over the application! Cool, right!?
As we know we need a LifeCycleOwner (e.g Fragment or FragmentActivity) to create ViewModels, when the owner is at the end of its lifecycle the ViewModel will be cleared as well, Sometimes you need to share the ViewModel between multiple owners, By default we can only share ViewModel of an activity between its fragments for now, nothing more...
- Creates ViewModels with Single Owner: This is the default ViewModel behavior that already has, The ViewModels created in this way are only available to the owner.
- Creates ViewModels with Multiple Owners: The ViewModels are shared between multiple owners and stay alive while at least one owner is alive
- Creates ViewModels with No Owner: The ViewModels have no owner, they are available in the application scope and stay alive until the user closes the application
Make sure your project includes mavenCentral in its repositories and add this to build.gradle in app module
dependencies {
implementation 'com.androidisland.arch:vita:$latest_version'
}
First start Vita in application class:
class App : Application() {
override fun onCreate() {
super.onCreate()
startVita()
}
}
There is an extension value named vita that gives you access to a singleton object of Vita everywhere, Just pass your desired VitaOwner and get the ViewModel you want:
val myViewModel = vita.with(VitaOwner.Multiple(this)).getViewModel<MyViewModel>()
Also you can pass a function as factory like this:
val myViewModelWithFactory = vita.with(VitaOwner.Multiple(this)).getViewModel(){ MyViewModelWithFactory(initData) }
Copyright 2019 Farshad Tahmasbi
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