[Entanglement] Add Go To Original

nasa/openmctweb#147

platform/entanglement/bundle.json

@@ -30,6 +30,14 @@
                 "category": "contextual",
                 "implementation": "actions/LinkAction.js",
                 "depends": ["locationService", "linkService"]
+            },
+            {
+                "key": "follow",
+                "name": "Go To Original",
+                "description": "Go to the original, un-linked instance of this object.",
+                "glyph": "\u00F4",
+                "category": "contextual",
+                "implementation": "actions/GoToOriginalAction.js"
             }
         ],
         "components": [

platform/entanglement/src/actions/GoToOriginalAction.js

@@ -0,0 +1,62 @@
+/*****************************************************************************
+ * 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 */
+define(
+    function () {
+        "use strict";
+
+        /**
+         * Implements the "Go To Original" action, which follows a link back
+         * to an original instance of an object.
+         *
+         * @implements {Action}
+         * @constructor
+         * @private
+         * @memberof platform/entanglement
+         * @param {ActionContext} context the context in which the action
+         *        will be performed
+         */
+        function GoToOriginalAction(context) {
+            this.domainObject = context.domainObject;
+        }
+
+        GoToOriginalAction.prototype.perform = function () {
+            return this.domainObject.getCapability("location").getOriginal()
+                .then(function (originalObject) {
+                    var actionCapability =
+                        originalObject.getCapability("action");
+                    return actionCapability &&
+                            actionCapability.perform("navigate");
+                });
+        };
+
+        GoToOriginalAction.appliesTo = function (context) {
+            var domainObject = context.domainObject;
+            return domainObject && domainObject.hasCapability("location")
+                && domainObject.getCapability("location").isLink();
+        };
+
+        return GoToOriginalAction;
+    }
+);
+