[Persistence] Implement aggregator

platform/persistence/aggregator/src/PersistenceAggregator.js

@@ -0,0 +1,80 @@
+/*****************************************************************************
+ * Open MCT Web, Copyright (c) 2014-2015, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT Web 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 Web 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.
+ *****************************************************************************/
+
+/*global define,window*/
+
+define(
+    [],
+    function () {
+        'use strict';
+
+        var METHOD_DEFAULTS = {
+            createObject: false,
+            readObject: undefined,
+            listObjects: [],
+            updateObject: false,
+            deleteObject: false
+        };
+
+        /**
+         * @memberof platform/persistence/aggregator
+         * @constructor
+         * @implements {PersistenceService}
+         * @param q Angular's $q, for promises
+         */
+        function PersistenceAggregator($q, providers) {
+            var providerMap = {};
+
+            function addToMap(provider) {
+                return provider.listSpaces().then(function (spaces) {
+                    spaces.forEach(function (space) {
+                        providerMap[space] = providerMap[space] || provider;
+                    });
+                });
+            }
+
+            this.$q = $q;
+            this.providerMapPromise = $q.all(providers.map(addToMap))
+                .then(function () { return providerMap; });
+        }
+
+        PersistenceAggregator.prototype.listSpaces = function () {
+            return this.providerMapPromise.then(function (map) {
+                return Object.keys(map);
+            });
+        };
+
+        Object.keys(METHOD_DEFAULTS).forEach(function (method) {
+            PersistenceAggregator.prototype[method] = function (space) {
+                var delegateArgs = arguments.slice(0);
+                return this.providerMapPromise.then(function (map) {
+                    var provider = map[space];
+                    return provider ?
+                            provider.apply(provider, delegateArgs) :
+                            METHOD_DEFAULTS[method];
+                });
+            };
+        });
+
+        return PersistenceAggregator;
+    }
+);