[Location] Add getOriginal method

Add a getOriginal method to the location capability, to simplify
loading of original versions of objects. nasa/openmctweb#147

platform/entanglement/bundle.json

@@ -52,7 +52,8 @@
                 "key": "location",
                 "name": "Location Capability",
                 "description": "Provides a capability for retrieving the location of an object based upon it's context.",
-                "implementation": "capabilities/LocationCapability"
+                "implementation": "capabilities/LocationCapability",
+                "depends": [ "$q", "$injector" ]
             }
         ],
         "services": [

platform/entanglement/src/capabilities/LocationCapability.js

@@ -12,11 +12,41 @@ define(
          *
          * @constructor
          */
-        function LocationCapability(domainObject) {
+        function LocationCapability($q, $injector, domainObject) {
             this.domainObject = domainObject;
+            this.$q = $q;
+            this.$injector = $injector;
             return this;
         }
 
+        /**
+         * Get an instance of this domain object in its original location.
+         *
+         * @returns {Promise.<DomainObject>} a promise for the original
+         *          instance of this domain object
+         */
+        LocationCapability.prototype.getOriginal = function () {
+            var id;
+
+            if (this.isOriginal()) {
+                return this.$q.when(this.domainObject);
+            }
+
+            id = this.domainObject.getId();
+
+            this.objectService =
+                this.objectService || this.$injector.get("objectService");
+
+            // Assume that an object will be correctly contextualized when
+            // loaded directly from the object service; this is true
+            // so long as LocatingObjectDecorator is present, and that
+            // decorator is also contained in this bundle.
+            return this.objectService.getObjects([id])
+                .then(function (objects) {
+                    return objects[id];
+                });
+        };
+
         /**
          * Set the primary location (the parent id) of the current domain
          * object.
@@ -78,10 +108,6 @@ define(
             return !this.isLink();
         };
 
-        function createLocationCapability(domainObject) {
+        return LocationCapability;
-            return new LocationCapability(domainObject);
-        }
-
-        return createLocationCapability;
     }
 );

platform/entanglement/test/capabilities/LocationCapabilitySpec.js

@@ -7,6 +7,7 @@ define(
         '../ControlledPromise'
     ],
     function (LocationCapability, domainObjectFactory, ControlledPromise) {
+        'use strict';
 
         describe("LocationCapability", function () {
 
@@ -14,13 +15,16 @@ define(
                 var locationCapability,
                     persistencePromise,
                     mutationPromise,
+                    mockQ,
+                    mockInjector,
+                    mockObjectService,
                     domainObject;
 
                 beforeEach(function () {
                     domainObject = domainObjectFactory({
                         capabilities: {
                             context: {
-                                getParent: function() {
+                                getParent: function () {
                                     return domainObjectFactory({id: 'root'});
                                 }
                             },
@@ -35,6 +39,11 @@ define(
                         }
                     });
 
+                    mockQ = jasmine.createSpyObj("$q", ["when"]);
+                    mockInjector = jasmine.createSpyObj("$injector", ["get"]);
+                    mockObjectService =
+                        jasmine.createSpyObj("objectService", ["getObjects"]);
+
                     persistencePromise = new ControlledPromise();
                     domainObject.capabilities.persistence.persist.andReturn(
                         persistencePromise
@@ -49,7 +58,11 @@ define(
                         }
                     );
 
-                    locationCapability = new LocationCapability(domainObject);
+                    locationCapability = new LocationCapability(
+                        mockQ,
+                        mockObjectService,
+                        domainObject
+                    );
                 });
 
                 it("returns contextual location", function () {