[Code Style] Use prototypes in platform

WTD-1482

platform/core/src/capabilities/MetadataCapability.js

@@ -11,8 +11,6 @@ define(
          * @property {string} name the human-readable name of this property
          * @property {string} value the human-readable value of this property,
          *           for this specific domain object
-         * @constructor
-         * @memberof platform/core
          */
 
         var TIME_FORMAT = "YYYY-MM-DD HH:mm:ss";
@@ -27,10 +25,23 @@ define(
          * `value` properties describing that domain object (suitable for
          * display.)
          *
+         * @param {DomainObject} domainObject the domain object whose
+         *        metadata is to be exposed
+         * @implements {Capability}
          * @constructor
+         * @memberof platform/core
          */
         function MetadataCapability(domainObject) {
-            var model = domainObject.getModel();
+            this.domainObject = domainObject;
+        }
+
+        /**
+         * Get metadata about this object.
+         * @returns {MetadataProperty[]} metadata about this object
+         */
+        MetadataCapability.prototype.invoke = function () {
+            var domainObject = this.domainObject,
+                model = domainObject.getModel();
 
             function hasDisplayableValue(metadataProperty) {
                 var t = typeof metadataProperty.value;
@@ -39,8 +50,8 @@ define(
 
             function formatTimestamp(timestamp) {
                 return typeof timestamp === 'number' ?
-                        (moment.utc(timestamp).format(TIME_FORMAT) + " UTC") :
-                        undefined;
+                    (moment.utc(timestamp).format(TIME_FORMAT) + " UTC") :
+                    undefined;
             }
 
             function getProperties() {
@@ -75,20 +86,9 @@ define(
                 ];
             }
 
-            function getMetadata() {
-                return getProperties().concat(getCommonMetadata())
-                    .filter(hasDisplayableValue);
-            }
-
-            return {
-                /**
-                 * Get metadata about this object.
-                 * @returns {MetadataProperty[]} metadata about this object
-                 * @memberof platform/core.MetadataCapability#
-                 */
-                invoke: getMetadata
-            };
-        }
+            return getProperties().concat(getCommonMetadata())
+                .filter(hasDisplayableValue);
+        };
 
         return MetadataCapability;
     }