Initial pass at refactoring composition. Completely broken

src/api/composition/CompositionCollection.js

@@ -20,6 +20,7 @@
  * at runtime from the About dialog for additional information.
  *****************************************************************************/
 
+import EventEmitter from 'EventEmitter';
 /**
  * @typedef {import('../objects/ObjectAPI').DomainObject} DomainObject
  */
@@ -60,6 +61,10 @@ export default class CompositionCollection {
     #publicAPI;
     #listeners;
     #mutables;
+    #onGlobalAdd;
+    #onGlobalRemove;
+    static #globalEvents = new EventEmitter();
+
     /**
      * @constructor
      * @param {DomainObject} domainObject the domain object
@@ -95,6 +100,21 @@ export default class CompositionCollection {
                 unobserve();
             });
         }
+
+        const keyString = publicAPI.objects.makeKeyString(domainObject.identifier);
+        this.#onGlobalAdd = this._onGlobalAdd.bind(this);
+        this.#onGlobalRemove = this._onGlobalRemove.bind(this);
+
+        CompositionCollection.#globalEvents.on(`add:${keyString}`, this.#onGlobalAdd);
+        CompositionCollection.#globalEvents.on(`remove:${keyString}`, this.#onGlobalRemove);
+    }
+
+    _onGlobalAdd(object) {
+        this.#emit('add', object);
+    }
+
+    _onGlobalRemove(identifier) {
+        this.#emit('remove', identifier);
     }
     /**
      * Listen for changes to this composition.  Supports 'add', 'remove', and
@@ -209,23 +229,21 @@ export default class CompositionCollection {
      * **Intended for internal use ONLY.**
      * true if the underlying provider should not be updated.
      */
-    add(child, skipMutate) {
+    add(child) {
-        if (!skipMutate) {
+        if (!this.#publicAPI.composition.checkPolicy(this.domainObject, child)) {
-            if (!this.#publicAPI.composition.checkPolicy(this.domainObject, child)) {
+            throw `Object of type ${child.type} cannot be added to object of type ${this.domainObject.type}`;
-                throw `Object of type ${child.type} cannot be added to object of type ${this.domainObject.type}`;
-            }
-
-            this.#provider.add(this.domainObject, child.identifier);
-        } else {
-            if (this.returnMutables && this.#publicAPI.objects.supportsMutation(child.identifier)) {
-                let keyString = this.#publicAPI.objects.makeKeyString(child.identifier);
-
-                child = this.#publicAPI.objects.toMutable(child);
-                this.#mutables[keyString] = child;
-            }
-
-            this.#emit('add', child);
         }
+
+        this.#provider.add(this.domainObject, child.identifier);
+        if (this.returnMutables && this.#publicAPI.objects.supportsMutation(child.identifier)) {
+            let keyString = this.#publicAPI.objects.makeKeyString(child.identifier);
+
+            child = this.#publicAPI.objects.toMutable(child);
+            this.#mutables[keyString] = child;
+        }
+
+        // const keyString = this.#publicAPI.objects.makeKeyString(this.domainObject.identifier);
+        // CompositionCollection.#globalEvents.emit(`add:${keyString}`, child);
     }
     /**
      * Load the domain objects in this composition.
@@ -240,7 +258,12 @@ export default class CompositionCollection {
         this.#cleanUpMutables();
         const children = await this.#provider.load(this.domainObject);
         const childObjects = await Promise.all(children.map((c) => this.#publicAPI.objects.get(c, abortSignal)));
-        childObjects.forEach(c => this.add(c, true));
+        childObjects.forEach(c => {
+            this.add(c);
+
+            const keyString = this.#publicAPI.objects.makeKeyString(this.domainObject.identifier);
+            CompositionCollection.#globalEvents.emit(`add:${keyString}`, c);
+        });
         this.#emit('load');
 
         return childObjects;
@@ -259,20 +282,18 @@ export default class CompositionCollection {
      * true if the underlying provider should not be updated.
      * @name remove
      */
-    remove(child, skipMutate) {
+    remove(child) {
-        if (!skipMutate) {
+        this.#provider.remove(this.domainObject, child.identifier);
-            this.#provider.remove(this.domainObject, child.identifier);
+        if (this.returnMutables) {
-        } else {
+            let keyString = this.#publicAPI.objects.makeKeyString(child);
-            if (this.returnMutables) {
+            if (this.#mutables[keyString] !== undefined && this.#mutables[keyString].isMutable) {
-                let keyString = this.#publicAPI.objects.makeKeyString(child);
+                this.#publicAPI.objects.destroyMutable(this.#mutables[keyString]);
-                if (this.#mutables[keyString] !== undefined && this.#mutables[keyString].isMutable) {
+                delete this.#mutables[keyString];
-                    this.#publicAPI.objects.destroyMutable(this.#mutables[keyString]);
-                    delete this.#mutables[keyString];
-                }
             }
-
-            this.#emit('remove', child);
         }
+
+        // const keyString = this.#publicAPI.objects.makeKeyString(this.domainObject.identifier);
+        // CompositionCollection.#globalEvents.emit(`remove:${keyString}`, child.identifier);
     }
     /**
      * Reorder the domain objects in this composition.
@@ -295,6 +316,10 @@ export default class CompositionCollection {
             this.mutationListener();
             delete this.mutationListener;
         }
+
+        const keyString = this.#publicAPI.objects.makeKeyString(this.domainObject.identifier);
+        CompositionCollection.#globalEvents.off(`add:${keyString}`, this.#onGlobalAdd);
+        CompositionCollection.#globalEvents.off(`remove:${keyString}`, this.#onGlobalRemove);
     }
     /**
      * Handle reorder from provider.

src/api/composition/CompositionProvider.js

@@ -71,10 +71,6 @@ export default class CompositionProvider {
         return this.#listeningTo;
     }
 
-    get establishTopicListener() {
-        return this.#establishTopicListener.bind(this);
-    }
-
     get publicAPI() {
         return this.#publicAPI;
     }
@@ -181,22 +177,6 @@ export default class CompositionProvider {
         throw new Error("This method must be implemented by a subclass.");
     }
 
-    /**
-      * Listens on general mutation topic, using injector to fetch to avoid
-      * circular dependencies.
-      * @private
-      */
-    #establishTopicListener() {
-        if (this.topicListener) {
-            return;
-        }
-
-        this.#publicAPI.objects.eventEmitter.on('mutation', this.#onMutation.bind(this));
-        this.topicListener = () => {
-            this.#publicAPI.objects.eventEmitter.off('mutation', this.#onMutation.bind(this));
-        };
-    }
-
     /**
       * @private
       * @param {DomainObject} parent
@@ -216,47 +196,5 @@ export default class CompositionProvider {
     #supportsComposition(parent, _child) {
         return this.#publicAPI.composition.supportsComposition(parent);
     }
-
-    /**
-      * Handles mutation events.  If there are active listeners for the mutated
-      * object, detects changes to composition and triggers necessary events.
-      *
-      * @private
-      * @param {DomainObject} oldDomainObject
-      */
-    #onMutation(oldDomainObject) {
-        const id = objectUtils.makeKeyString(oldDomainObject.identifier);
-        const listeners = this.#listeningTo[id];
-
-        if (!listeners) {
-            return;
-        }
-
-        const oldComposition = listeners.composition.map(objectUtils.makeKeyString);
-        const newComposition = oldDomainObject.composition.map(objectUtils.makeKeyString);
-
-        const added = _.difference(newComposition, oldComposition).map(objectUtils.parseKeyString);
-        const removed = _.difference(oldComposition, newComposition).map(objectUtils.parseKeyString);
-
-        function notify(value) {
-            return function (listener) {
-                if (listener.context) {
-                    listener.callback.call(listener.context, value);
-                } else {
-                    listener.callback(value);
-                }
-            };
-        }
-
-        listeners.composition = newComposition.map(objectUtils.parseKeyString);
-
-        added.forEach(function (addedChild) {
-            listeners.add.forEach(notify(addedChild));
-        });
-
-        removed.forEach(function (removedChild) {
-            listeners.remove.forEach(notify(removedChild));
-        });
-    }
 }
 

src/api/composition/DefaultCompositionProvider.js

@@ -89,7 +89,7 @@ export default class DefaultCompositionProvider extends CompositionProvider {
         event,
         callback,
         context) {
-        this.establishTopicListener();
+        //this.establishTopicListener();
 
         /** @type {string} */
         const keyString = objectUtils.makeKeyString(domainObject.identifier);
@@ -157,6 +157,8 @@ export default class DefaultCompositionProvider extends CompositionProvider {
         });
 
         this.publicAPI.objects.mutate(domainObject, 'composition', composition);
+
+        this.objectListeners.remove?.forEach(listener => listener.callback.apply(listener.context, childId));
     }
     /**
      * Add a domain object to another domain object's composition.
@@ -174,6 +176,8 @@ export default class DefaultCompositionProvider extends CompositionProvider {
         if (!this.includes(parent, childId)) {
             parent.composition.push(childId);
             this.publicAPI.objects.mutate(parent, 'composition', parent.composition);
+
+            this.objectListeners.add?.forEach(listener => listener.callback.apply(listener.context, childId));
         }
     }