[Representation] Separate out template loading/linking

...from mct-include, to facilitate reuse for MCTRepresentation.

platform/representation/bundle.json

@@ -4,7 +4,7 @@
             {
                 "key": "mctInclude",
                 "implementation": "MCTInclude.js",
-                "depends": [ "templates[]", "$sce", "$http", "$compile" ]
+                "depends": [ "templates[]", "templateLinker" ]
             },
             {
                 "key": "mctRepresentation",
@@ -48,6 +48,12 @@
                 "key": "dndService",
                 "implementation": "services/DndService.js",
                 "depends": [ "$log" ]
+            },
+            {
+                "key": "templateLinker",
+                "implementation": "TemplateLinker.js",
+                "depends": [ "$http", "$compile", "$log" ],
+                "comment": "For internal use by mct-include and mct-representation."
             }
         ],
         "actions": [

platform/representation/src/MCTInclude.js

@@ -54,59 +54,31 @@ define(
          * @param {TemplateDefinition[]} templates an array of
          *        template extensions
          */
-        function MCTInclude(templates, $sce, $http, $compile, $log) {
+        function MCTInclude(templates, templateLinker) {
             var templateMap = {};
 
-            function loadTemplate(path) {
+            function link(scope, element, attrs, ctrl, transclude) {
-                return $http.get(path).then(function (response) {
+                var changeTemplates = templateLinker.link(
-                    return $compile(response.data);
+                    scope,
-                });
+                    element,
-            }
+                    transclude
+                );
 
-            function addTemplate(key, $scope, element) {
+                scope.$watch('key', function (key) {
-                // Pass the template URL to ng-include via scope.
+                    changeTemplates(templateMap[key]);
-                //$scope.inclusion = templateMap[$scope.key];
-                // ...and add the template to the DOM.
-                templateMap[key].then(function (template) {
-                    template($scope, function (innerClone) {
-                        element.append(innerClone);
-                    });
-                }, function () {
-                    $log.warn("Could not load template " + key);
-                    delete templateMap[key];
-                });
-            }
-
-            function link($scope, element, attrs, ctrl, transclude) {
-                var originalElement = element,
-                    activeElement = element;
-
-                $scope.$watch('key', function (key) {
-                    if (templateMap[key]) {
-                        transclude(function (clone) {
-                            activeElement.replaceWith(clone);
-                            activeElement = clone;
-                            activeElement.empty();
-                            addTemplate(key, $scope, activeElement);
-                        });
-                    } else if (activeElement !== originalElement) {
-                        // If the key is unknown, remove it from DOM entirely.
-                        activeElement.replaceWith(originalElement);
-                        activeElement = originalElement;
-                    }
                 });
             }
 
             // Prepopulate templateMap for easy look up by key
             templates.forEach(function (template) {
                 var key = template.key,
-                    path = $sce.trustAsResourceUrl([
+                    path = [
                         template.bundle.path,
                         template.bundle.resources,
                         template.templateUrl
-                    ].join("/"));
+                    ].join("/");
                 // First found should win (priority ordering)
-                templateMap[key] = templateMap[key] || loadTemplate(path);
+                templateMap[key] = templateMap[key] || path;
             });
 
             return {

platform/representation/src/TemplateLinker.js

@@ -0,0 +1,106 @@
+/*****************************************************************************
+ * 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,Promise*/
+
+define(
+    [],
+    function () {
+        "use strict";
+
+        /**
+         * Pre-fetches templates and allows them to be
+         *
+         * @param {string[]} URLs to all templates which should be loadable
+         * @param $http Angular's `$http` service
+         * @param {Function} $compile Angular's `$compile` service
+         * @param $log Angular's `$log` service
+         */
+        function TemplateLinker($http, $compile, $log) {
+            this.templateMap = {};
+            this.$http = $http;
+            this.$compile = $compile;
+            this.$log = $log;
+        }
+
+        TemplateLinker.prototype.load = function (templateUrl) {
+            var $http = this.$http,
+                $compile = this.$compile,
+                $log = this.$log,
+                templateMap = this.templateMap;
+
+            return (templateMap[templateUrl] = templateMap[templateUrl] ||
+                $http.get(templateUrl).then(function (response) {
+                    return $compile(response.data);
+                }, function () {
+                    $log.warn("Couldn't load template at " + templateUrl);
+                    templateMap[templateUrl] = undefined;
+                }));
+        };
+
+        /**
+         * @returns {Function} a function which can be called with a template
+         *          URL to switch templates, or `undefined` to remove.
+         */
+        TemplateLinker.prototype.link = function (scope, element, transclude) {
+            var originalElement = element,
+                activeElement = element,
+                self = this;
+
+            function removeElement() {
+                if (activeElement !== originalElement) {
+                    activeElement.replaceWith(originalElement);
+                    activeElement = originalElement;
+                }
+            }
+
+            function replaceElement(clone, template) {
+                activeElement.replaceWith(clone);
+                activeElement = clone;
+                activeElement.empty();
+                template(scope, function (innerClone) {
+                    clone.append(innerClone);
+                });
+            }
+
+            function applyTemplate(template) {
+                if (template) {
+                    transclude(function (clone) {
+                        replaceElement(clone, template);
+                    });
+                } else {
+                    removeElement();
+                }
+            }
+
+            return function (templateUrl) {
+                if (templateUrl) {
+                    self.load(templateUrl).then(applyTemplate);
+                } else {
+                    removeElement();
+                }
+            };
+        };
+
+        return TemplateLinker;
+    }
+);
+