[Layout] Add notion of representers

Add representers as a category of extension; these are extra
steps to perform when representing a domain object. This
will be used to support automatic mutation/persistence of
domain objects from a watch, while avoiding bloat within
the mct-representation directive itself. This, in turn,
simplifies the persistence strategy to be employed by
Layout views when editing concludes. WTD-535.

platform/representation/bundle.json

@@ -9,7 +9,7 @@
             {
                 "key": "mctRepresentation",
                 "implementation": "MCTRepresentation.js",
-                "depends": [ "representations[]", "views[]", "gestureService", "$q", "$log" ]
+                "depends": [ "representations[]", "views[]", "representers[]", "$q", "$log" ]
             }
         ],
         "gestures": [
@@ -36,6 +36,12 @@
                 "implementation": "gestures/GestureProvider.js",
                 "depends": ["gestures[]"]
             }
+        ],
+        "representers": [
+            {
+                "implementation": "gestures/GestureRepresenter.js",
+                "depends": [ "gestureService" ]
+            }
         ]
     }
 }

platform/representation/src/MCTRepresentation.js

@@ -31,7 +31,7 @@ define(
          *        representation extensions
          * @param {ViewDefinition[]} views an array of view extensions
          */
-        function MCTRepresentation(representations, views, gestureService, $q, $log) {
+        function MCTRepresentation(representations, views, representers, $q, $log) {
             var pathMap = {},
                 representationMap = {},
                 gestureMap = {};
@@ -52,8 +52,10 @@ define(
             });
 
 
-            function link($scope, element) {
-                var gestureHandle;
+            function link($scope, element, attrs) {
+                var activeRepresenters = representers.map(function (Representer) {
+                    return new Representer($scope, element, attrs);
+                });
 
                 // General-purpose refresh mechanism; should set up the scope
                 // as appropriate for current representation key and
@@ -73,9 +75,9 @@ define(
                     $scope.inclusion = pathMap[$scope.key];
 
                     // Any existing gestures are no longer valid; release them.
-                    if (gestureHandle) {
-                        gestureHandle.destroy();
-                    }
+                    activeRepresenters.forEach(function (activeRepresenter) {
+                        activeRepresenter.destroy();
+                    });
 
                     // Log if a key was given, but no matching representation
                     // was found.
@@ -89,6 +91,11 @@ define(
                         // Always provide the model, as "model"
                         $scope.model = domainObject.getModel();
 
+                        // Also provide the view configuration,
+                        // for the specific view
+                        $scope.configuration =
+                            ($scope.model.configuration || {})[$scope.key] || {};
+
                         // Also provide any of the capabilities requested
                         uses.forEach(function (used) {
                             $log.debug([
@@ -104,13 +111,11 @@ define(
                             });
                         });
 
-                        // Finally, wire up any gestures that should be
-                        // associated with this representation.
-                        gestureHandle = gestureService.attachGestures(
-                            element,
-                            domainObject,
-                            gestureKeys
-                        );
+                        // Finally, wire up any additional behavior (such as
+                        // gestures) associated with this representation.
+                        activeRepresenters.forEach(function (representer) {
+                            representer.represent(representation, domainObject);
+                        });
                     }
                 }
 

platform/representation/src/gestures/GestureRepresenter.js

@@ -0,0 +1,37 @@
+/*global define*/
+
+define(
+    [],
+    function () {
+        "use strict";
+
+        function GestureRepresenter(gestureService, scope, element) {
+            var gestureHandle;
+
+            function destroy() {
+                if (gestureHandle) {
+                    gestureHandle.destroy();
+                }
+            }
+
+            function represent(representation, domainObject) {
+                // Clear out any existing gestures
+                destroy();
+
+                // Attach gestures - by way of the service.
+                gestureHandle = gestureService.attachGestures(
+                    element,
+                    domainObject,
+                    (representation || {}).gestures || []
+                );
+            }
+
+            return {
+                represent: represent,
+                destroy: destroy
+            };
+        }
+
+        return GestureRepresenter;
+    }
+);