Added onReactiveStateAttachedTo(parent)

Author: wkornewald

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 5.13.0
+
+* Added `OnReactiveStateAttachedTo.onReactiveStateAttachedTo(parent)`, so the ViewModel can finish its initialization and do additional checks against the parent (which can be the UI or a parent ViewModel).
+
 ## 5.12.0
 
 * Fixed `by childReactiveState` to call `onReactiveStateAttached(child)` (the arguments were inverted).

reactivestate-compose/src/composeMain/kotlin/com/ensody/reactivestate/compose/ViewModelExt.kt

@@ -14,6 +14,8 @@ import androidx.lifecycle.viewmodel.compose.viewModel
 import com.ensody.reactivestate.ErrorEvents
 import com.ensody.reactivestate.ExperimentalReactiveStateApi
 import com.ensody.reactivestate.InMemoryStateFlowStore
+import com.ensody.reactivestate.OnReactiveStateAttached
+import com.ensody.reactivestate.OnReactiveStateAttachedTo
 import com.ensody.reactivestate.ReactiveState
 import com.ensody.reactivestate.ReactiveStateContext
 import com.ensody.reactivestate.ReactiveViewModel
@@ -55,6 +57,8 @@ public inline fun <reified E : ErrorEvents, reified VM : ReactiveState<E>> E.rea
     observeLoadingEffect(viewModel)
     LaunchedEffect(this, viewModel.eventNotifier) {
         viewModel.eventNotifier.handleEvents(this@reactiveState)
+        (this@reactiveState as? OnReactiveStateAttached)?.onReactiveStateAttached(viewModel)
+        (viewModel as? OnReactiveStateAttachedTo)?.onReactiveStateAttachedTo(this@reactiveState)
     }
     return viewModel
 }

reactivestate-core/src/commonMain/kotlin/com/ensody/reactivestate/OnReactiveStateAttached.kt

@@ -7,5 +7,5 @@ package com.ensody.reactivestate
  * method in every UI screen (e.g. on Android you could have a `BaseFragment` implementing this interface).
  */
 public interface OnReactiveStateAttached {
-    public fun onReactiveStateAttached(reactiveState: ReactiveState<out ErrorEvents>)
+    public fun onReactiveStateAttached(child: ReactiveState<out ErrorEvents>)
 }

reactivestate-core/src/commonMain/kotlin/com/ensody/reactivestate/OnReactiveStateAttachedTo.kt

@@ -0,0 +1,10 @@
+package com.ensody.reactivestate
+
+/**
+ * Implement this interface to get notified when your [ReactiveState] is attached its parent (screen or ReactiveState).
+ *
+ * This can be useful e.g. to check if the parent
+ */
+public interface OnReactiveStateAttachedTo {
+    public fun onReactiveStateAttachedTo(parent: Any)
+}

reactivestate-core/src/commonMain/kotlin/com/ensody/reactivestate/ReactiveState.kt

@@ -105,6 +105,7 @@ public fun <E : ErrorEvents, P : ReactiveState<out E>, RS : ReactiveState<E>> P.
         eventNotifier.emitAll(child.eventNotifier)
     }
     (this as? OnReactiveStateAttached)?.onReactiveStateAttached(child)
+    (child as? OnReactiveStateAttachedTo)?.onReactiveStateAttachedTo(this)
     return WrapperProperty(child)
 }
 

reactivestate-core/src/commonMain/kotlin/com/ensody/reactivestate/ReactiveViewModel.kt

@@ -13,8 +13,8 @@ package com.ensody.reactivestate
 public abstract class ReactiveViewModel(
     /** This is `open` to allow overriding with a more specific type. */
     public open val context: ReactiveViewModelContext,
-) : BaseReactiveState<ErrorEvents>(context.scope) {
-    init {
+) : BaseReactiveState<ErrorEvents>(context.scope), OnReactiveStateAttachedTo {
+    override fun onReactiveStateAttachedTo(parent: Any) {
         context.preInit.trigger(this)
     }
 }

reactivestate/src/androidMain/kotlin/com/ensody/reactivestate/android/ReactiveViewModelExt.kt

@@ -10,6 +10,7 @@ import androidx.lifecycle.viewModelScope
 import com.ensody.reactivestate.ErrorEvents
 import com.ensody.reactivestate.NamespacedStateFlowStore
 import com.ensody.reactivestate.OnReactiveStateAttached
+import com.ensody.reactivestate.OnReactiveStateAttachedTo
 import com.ensody.reactivestate.ReactiveState
 import com.ensody.reactivestate.StateFlowStore
 import kotlinx.coroutines.CoroutineScope
@@ -48,6 +49,7 @@ public fun <E : ErrorEvents> Lazy<ReactiveState<E>>.attachLazyReactiveState(
     }
     owner.launchOnceStateAtLeast(Lifecycle.State.CREATED) {
         (owner as? OnReactiveStateAttached)?.onReactiveStateAttached(value)
+        (value as? OnReactiveStateAttachedTo)?.onReactiveStateAttachedTo(owner)
     }
 }
 

reactivestate/src/androidUnitTest/kotlin/com/ensody/reactivestate/android/TestFragment.kt

@@ -48,7 +48,7 @@ internal class TestFragment : Fragment(), ErrorEvents, OnReactiveStateAttached {
         errors.add(error)
     }
 
-    override fun onReactiveStateAttached(reactiveState: ReactiveState<out ErrorEvents>) {
-        attachedReactiveStates.add(reactiveState)
+    override fun onReactiveStateAttached(child: ReactiveState<out ErrorEvents>) {
+        attachedReactiveStates.add(child)
     }
 }