[API] Changes to mutation API

platform/commonUI/edit/src/policies/EditPersistableObjectsPolicy.js

@@ -44,9 +44,9 @@ define(
             // is also invoked during the create process which should be allowed,
             // because it may be saved elsewhere
             if ((key === 'edit' && category === 'view-control') || key === 'properties') {
-                let newStyleObject = objectUtils.toNewFormat(domainObject, domainObject.getId());
+                let identifier = this.openmct.objects.parseKeyString(domainObject.getId());
 
-                return this.openmct.objects.isPersistable(newStyleObject);
+                return this.openmct.objects.isPersistable(identifier);
             }
 
             return true;

platform/commonUI/edit/test/policies/EditPersistableObjectsSpec.js

@@ -43,7 +43,8 @@ define(
                 );
 
                 mockObjectAPI = jasmine.createSpyObj('objectAPI', [
-                    'isPersistable'
+                    'isPersistable',
+                    'parseKeyString'
                 ]);
 
                 mockAPI = {

platform/containment/src/PersistableCompositionPolicy.js

@@ -48,9 +48,9 @@ define(
             // prevents editing of objects that cannot be persisted, so we can assume that this
             // is a new object.
             if (!(parent.hasCapability('editor') && parent.getCapability('editor').isEditContextRoot())) {
-                let newStyleObject = objectUtils.toNewFormat(parent, parent.getId());
+                let identifier = this.openmct.objects.parseKeyString(parent.getId());
 
-                return this.openmct.objects.isPersistable(newStyleObject);
+                return this.openmct.objects.isPersistable(identifier);
             }
 
             return true;

platform/containment/test/PersistableCompositionPolicySpec.js

@@ -33,7 +33,8 @@ define(
 
             beforeEach(function () {
                 objectAPI = jasmine.createSpyObj('objectsAPI', [
-                    'isPersistable'
+                    'isPersistable',
+                    'parseKeyString'
                 ]);
 
                 mockOpenMCT = {

src/MCT.js

@@ -219,7 +219,7 @@ define([
          * @memberof module:openmct.MCT#
          * @name objects
          */
-        this.objects = new api.ObjectAPI();
+        this.objects = new api.ObjectAPI.default(this.types);
 
         /**
          * An interface for retrieving and interpreting telemetry data associated
@@ -371,7 +371,7 @@ define([
      *        MCT; if undefined, MCT will be run in the body of the document
      */
     MCT.prototype.start = function (domElement = document.body, isHeadlessMode = false) {
-        if (!this.plugins.DisplayLayout._installed) {
+        if (this.types.get('layout') === undefined) {
             this.install(this.plugins.DisplayLayout({
                 showAsView: ['summary-widget']
             }));

src/adapter/services/LegacyObjectAPIInterceptor.js

@@ -61,6 +61,7 @@ define([
             const newStyleObject = utils.toNewFormat(legacyObject.getModel(), legacyObject.getId());
             const keystring = utils.makeKeyString(newStyleObject.identifier);
 
+            this.eventEmitter.emit(keystring + ':$_synchronize_model', newStyleObject);
             this.eventEmitter.emit(keystring + ":*", newStyleObject);
             this.eventEmitter.emit('mutation', newStyleObject);
         }.bind(this);

src/api/actions/ActionCollectionSpec.js

@@ -50,6 +50,10 @@ describe('The ActionCollection', () => {
                 }
             }
         ];
+        openmct.objects.addProvider('', jasmine.createSpyObj('mockMutableObjectProvider', [
+            'create',
+            'update'
+        ]));
         mockView = {
             getViewContext: () => {
                 return {

src/api/composition/CompositionCollection.js

@@ -60,6 +60,17 @@ define([
         };
         this.onProviderAdd = this.onProviderAdd.bind(this);
         this.onProviderRemove = this.onProviderRemove.bind(this);
+        this.mutables = {};
+
+        if (this.domainObject.isMutable) {
+            this.returnMutables = true;
+            let unobserve = this.domainObject.$on('$_destroy', () => {
+                Object.values(this.mutables).forEach(mutable => {
+                    this.publicAPI.objects.destroyMutable(mutable);
+                });
+                unobserve();
+            });
+        }
     }
 
     /**
@@ -75,10 +86,6 @@ define([
             throw new Error('Event not supported by composition: ' + event);
         }
 
-        if (!this.mutationListener) {
-            this._synchronize();
-        }
-
         if (this.provider.on && this.provider.off) {
             if (event === 'add') {
                 this.provider.on(
@@ -189,6 +196,13 @@ define([
 
             this.provider.add(this.domainObject, child.identifier);
         } else {
+            if (this.returnMutables && this.publicAPI.objects.supportsMutation(child)) {
+                let keyString = this.publicAPI.objects.makeKeyString(child.identifier);
+
+                child = this.publicAPI.objects._toMutable(child);
+                this.mutables[keyString] = child;
+            }
+
             this.emit('add', child);
         }
     };
@@ -202,6 +216,8 @@ define([
      * @name load
      */
     CompositionCollection.prototype.load = function () {
+        this.cleanUpMutables();
+
         return this.provider.load(this.domainObject)
             .then(function (children) {
                 return Promise.all(children.map((c) => this.publicAPI.objects.get(c)));
@@ -234,6 +250,14 @@ define([
         if (!skipMutate) {
             this.provider.remove(this.domainObject, child.identifier);
         } else {
+            if (this.returnMutables) {
+                let keyString = this.publicAPI.objects.makeKeyString(child);
+                if (this.mutables[keyString] !== undefined && this.mutables[keyString].isMutable) {
+                    this.publicAPI.objects.destroyMutable(this.mutables[keyString]);
+                    delete this.mutables[keyString];
+                }
+            }
+
             this.emit('remove', child);
         }
     };
@@ -281,12 +305,6 @@ define([
         this.remove(child, true);
     };
 
-    CompositionCollection.prototype._synchronize = function () {
-        this.mutationListener = this.publicAPI.objects.observe(this.domainObject, '*', (newDomainObject) => {
-            this.domainObject = JSON.parse(JSON.stringify(newDomainObject));
-        });
-    };
-
     CompositionCollection.prototype._destroy = function () {
         if (this.mutationListener) {
             this.mutationListener();
@@ -308,5 +326,11 @@ define([
         });
     };
 
+    CompositionCollection.prototype.cleanUpMutables = function () {
+        Object.values(this.mutables).forEach(mutable => {
+            this.publicAPI.objects.destroyMutable(mutable);
+        });
+    };
+
     return CompositionCollection;
 });

src/api/objects/MutableDomainObject.js

@@ -0,0 +1,137 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2020, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+import _ from 'lodash';
+import utils from './object-utils.js';
+import EventEmitter from 'EventEmitter';
+
+const ANY_OBJECT_EVENT = 'mutation';
+
+/**
+ * Wraps a domain object to keep its model synchronized with other instances of the same object.
+ *
+ * Creating a MutableDomainObject will automatically register listeners to keep its model in sync. As such, developers
+ * should be careful to destroy MutableDomainObject in order to avoid memory leaks.
+ *
+ * All Open MCT API functions that provide objects will provide MutableDomainObjects where possible, except
+ * `openmct.objects.get()`, and will manage that object's lifecycle for you. Calling `openmct.objects.getMutable()`
+ * will result in the creation of a new MutableDomainObject and you will be responsible for destroying it
+ * (via openmct.objects.destroy) when you're done with it.
+ *
+ * @typedef MutableDomainObject
+ * @memberof module:openmct
+ */
+class MutableDomainObject {
+    constructor(eventEmitter) {
+        Object.defineProperties(this, {
+            _globalEventEmitter: {
+                value: eventEmitter,
+                // Property should not be serialized
+                enumerable: false
+            },
+            _instanceEventEmitter: {
+                value: new EventEmitter(),
+                // Property should not be serialized
+                enumerable: false
+            },
+            _observers: {
+                value: [],
+                // Property should not be serialized
+                enumerable: false
+            },
+            isMutable: {
+                value: true,
+                // Property should not be serialized
+                enumerable: false
+            }
+        });
+    }
+    $observe(path, callback) {
+        let fullPath = qualifiedEventName(this, path);
+        let eventOff =
+            this._globalEventEmitter.off.bind(this._globalEventEmitter, fullPath, callback);
+
+        this._globalEventEmitter.on(fullPath, callback);
+        this._observers.push(eventOff);
+
+        return eventOff;
+    }
+    $set(path, value) {
+        _.set(this, path, value);
+        _.set(this, 'modified', Date.now());
+
+        //Emit secret synchronization event first, so that all objects are in sync before subsequent events fired.
+        this._globalEventEmitter.emit(qualifiedEventName(this, '$_synchronize_model'), this);
+
+        //Emit a general "any object" event
+        this._globalEventEmitter.emit(ANY_OBJECT_EVENT, this);
+        //Emit wildcard event, with path so that callback knows what changed
+        this._globalEventEmitter.emit(qualifiedEventName(this, '*'), this, path, value);
+
+        //Emit events specific to properties affected
+        let parentPropertiesList = path.split('.');
+        for (let index = parentPropertiesList.length; index > 0; index--) {
+            let parentPropertyPath = parentPropertiesList.slice(0, index).join('.');
+            this._globalEventEmitter.emit(qualifiedEventName(this, parentPropertyPath), _.get(this, parentPropertyPath));
+        }
+
+        //TODO: Emit events for listeners of child properties when parent changes.
+        // Do it at observer time - also register observers for parent attribute path.
+    }
+    $on(event, callback) {
+        this._instanceEventEmitter.on(event, callback);
+
+        return () => this._instanceEventEmitter.off(event, callback);
+    }
+    $destroy() {
+        this._observers.forEach(observer => observer());
+        delete this._globalEventEmitter;
+        delete this._observers;
+        this._instanceEventEmitter.emit('$_destroy');
+    }
+
+    static createMutable(object, mutationTopic) {
+        let mutable = Object.create(new MutableDomainObject(mutationTopic));
+        Object.assign(mutable, object);
+
+        mutable.$observe('$_synchronize_model', (updatedObject) => {
+            let clone = JSON.parse(JSON.stringify(updatedObject));
+            let deleted = _.difference(Object.keys(mutable), Object.keys(updatedObject));
+            deleted.forEach((propertyName) => delete mutable[propertyName]);
+            Object.assign(mutable, clone);
+        });
+
+        return mutable;
+    }
+
+    static mutateObject(object, path, value) {
+        _.set(object, path, value);
+        _.set(object, 'modified', Date.now());
+    }
+}
+
+function qualifiedEventName(object, eventName) {
+    let keystring = utils.makeKeyString(object.identifier);
+
+    return [keystring, eventName].join(':');
+}
+
+export default MutableDomainObject;