Bind the composer strictly to the component lifecycle

Author: pcastornii

README.md

@@ -270,9 +270,11 @@ public class FooView extends AbstractChildView<FooViewModel> {
 }
 ```
 
-Composer Assignment. To assign a `Composer` to a `View` and a `Mediator` to a `ViewModel`, use the public method
-`AbstractComponentView#setComposer(...)`. There is also a `AbstractComponentView#createComposer()` method, which can
-be overridden to automatically create the `Composer` during construction.
+Composer Creation and Initialization. The `Composer` is created during the component’s pre-initialization phase via
+the protected `AbstractComponentView#createComposer()` method. Creating the composer at this stage ensures that both
+the `View` and the `ViewModel` are fully constructed, allowing the composer to immediately access and interact with
+their properties and methods. The composer is also initialized during the pre-initialization phase, while its
+deinitialization takes place in the component’s post-deinitialization phase.
 
 Advantages of this approach:
 

mvvm4fx-core/src/main/java/com/techsenger/mvvm4fx/core/AbstractComponentView.java

@@ -33,7 +33,6 @@ public abstract class AbstractComponentView<T extends AbstractComponentViewModel
 
     public AbstractComponentView(T viewModel) {
         this.viewModel = viewModel;
-        setComposer(createComposer());
     }
 
     @Override
@@ -95,34 +94,11 @@ public ComponentComposer<?> getComposer() {
         return composer;
     }
 
-    /**
-     * Sets the {@link ComponentComposer} for this view and updates the view model with the corresponding
-     * {@link ComposerMediator}.
-     *
-     * <p>When a non-{@code null} composer is provided, the view becomes associated with that composer, and the view
-     * model receives the mediator obtained via {@link ComponentComposer#getMediator()}. This mediator enables
-     * communication between the view model and the rest of the component through the composer.
-     *
-     * <p>If {@code composer} is {@code null}, the view is detached from any composer, and the view model's mediator
-     * is cleared as well, effectively disconnecting both layers from the component's composition mechanism.
-     *
-     * @param composer the composer to attach to this view, or {@code null} to detach
-     */
-    public void setComposer(ComponentComposer<?> composer) {
-        this.composer = composer;
-        if (composer == null) {
-            viewModel.setMediator(null);
-        } else {
-            viewModel.setMediator(composer.getMediator());
-        }
-    }
-
     /**
      * Creates a new {@link ComponentComposer} instance for this component.
      *
-     * <p>This method is invoked during the component's construction phase and allows subclasses to provide a custom
-     * composer implementation. However, this method should be used only if the component is the owner of the composer.
-     * Otherwise the component setter should be used.
+     * <p>This method is invoked during the component's pre-initialization phase and allows subclasses to provide
+     * a custom composer implementation.
      *
      * <p>The default implementation returns {@code null}, meaning the component does not create a composer by default.
      *
@@ -146,7 +122,11 @@ protected ComponentDescriptor getDescriptor() {
      * The first method called in initialization.
      */
     protected void preInitialize(T viewModel) {
-
+        this.composer = createComposer();
+        if (this.composer != null) {
+            viewModel.setMediator(this.composer.getMediator());
+            this.composer.initialize();
+        }
     }
 
     /**
@@ -230,6 +210,8 @@ protected void unbuild(T viewModel) {
      * The last method called in deinitialization.
      */
     protected void postDeinitialize(T viewModel) {
-
+        if (this.composer != null) {
+            this.composer.deinitialize();
+        }
     }
 }

mvvm4fx-core/src/main/java/com/techsenger/mvvm4fx/core/AbstractComponentViewModel.java

@@ -117,10 +117,6 @@ public ComponentMediator getMediator() {
         return this.mediator;
     }
 
-    protected void setMediator(ComponentMediator mediator) {
-        this.mediator = mediator;
-    }
-
     protected void initialize() {
 
     }
@@ -139,6 +135,10 @@ protected void deinitialize() {
 
     protected abstract ComponentDescriptor createDescriptor();
 
+    void setMediator(ComponentMediator mediator) {
+        this.mediator = mediator;
+    }
+
     private ComponentHistory getOrRequestHistory() {
         if (this.history == null) {
             if (this.historyProvider == null) {