GraphRegistry

An object version of WinterTree that uses Winter as its WinterApplication.

Here an Android example where we use this to create a presentation graph that survives configuration changes and an Activity graph that gets recreated every time.

It is recommended to hide such details in a WinterInjection.Adapter.

Create the application object graph on application start:

class MyApplication : Application() {
  override fun onCreate() {
    super.onCreate()

    // Register the application component
    Winter.component {
      // A presentation subcomponent that survives orientation changes
      subcomponent("presentation") {
        // The activity subcomponent that gets recreated with every device rotation
        subcomponent("activity") {
        }
      }
    }

    // open the application graph
    GraphRegistry.open() {
      constant<Application> { this@MyApplication }
      constant<Context> { this@MyApplication }
    }
  }
}

Create the presenter and activity object subgraphs by their paths (of qualifiers):

class MyActivity : Activity() {

  override fun onCreate(savedInstanceState: Bundle?) {
    // Open the presentation graph if not already open.
    // Since we could have multiple activity instances at the same time we use the Activity class
    // as an identifier for the presentation graph.
    if (!GraphRegistry.has(javaClass)) GraphRegistry.open("presentation", identifier = javaClass)

    // Open the activity graph.
    // Here the same but we use the instance as identifier for the activity graph.
    GraphRegistry.open(javaClass, "activity", identifier = this) {
      constant<Context>(this@MyActivity)
      constant<Activity>(this@MyActivity)
    }
    super.onCreate(savedInstanceState)
  }

  override fun onDestroy() {
    // If we are leaving the scope of the activity then we close the "presentation" graph.
    if (isFinishing) {
      GraphRegistry.close(javaClass)
    // And if this is just recreating then we just close the "activity" graph.
    } else {
      GraphRegistry.close(javaClass, this)
    }
    super.onDestroy()
  }

}

See Also

WinterTree

Inherited Functions