From bcc42d705ea5024f155617b5bceea20d6b6b4fd8 Mon Sep 17 00:00:00 2001
From: Victor Woeltjen <victor.woeltjen@nasa.gov>
Date: Wed, 28 Oct 2015 15:29:57 -0700
Subject: [PATCH] [Representation] Hide elements without transclusion

---
 platform/representation/src/MCTInclude.js     | 16 ++-------
 .../representation/src/MCTRepresentation.js   | 34 +++++++------------
 platform/representation/src/TemplateLinker.js | 26 +++++++-------
 3 files changed, 29 insertions(+), 47 deletions(-)

diff --git a/platform/representation/src/MCTInclude.js b/platform/representation/src/MCTInclude.js
index 400a9d3ad8..e00ef8599d 100644
--- a/platform/representation/src/MCTInclude.js
+++ b/platform/representation/src/MCTInclude.js
@@ -57,15 +57,11 @@ define(
         function MCTInclude(templates, templateLinker) {
             var templateMap = {};
 
-            function link(scope, element, attrs, ctrl, transclude) {
-                var changeTemplates = templateLinker.link(
-                    scope,
-                    element,
-                    transclude
-                );
+            function link(scope, element) {
+                var changeTemplate = templateLinker.link(scope, element);
 
                 scope.$watch('key', function (key) {
-                    changeTemplates(templateMap[key]);
+                    changeTemplate(templateMap[key]);
                 });
             }
 
@@ -82,12 +78,6 @@ define(
             });
 
             return {
-                transclude: 'element',
-
-                priority: 601,
-
-                terminal: true,
-
                 // Only show at the element level
                 restrict: "E",
 
diff --git a/platform/representation/src/MCTRepresentation.js b/platform/representation/src/MCTRepresentation.js
index cefda36b42..9d5f612960 100644
--- a/platform/representation/src/MCTRepresentation.js
+++ b/platform/representation/src/MCTRepresentation.js
@@ -100,11 +100,7 @@ define(
                     }),
                     toClear = [], // Properties to clear out of scope on change
                     counter = 0,
-                    changeTemplate = templateLinker.link(
-                        $scope,
-                        element,
-                        transclude
-                    );
+                    changeTemplate = templateLinker.link($scope, element);
 
                 // Populate scope with any capabilities indicated by the
                 // representation's extension definition
@@ -155,15 +151,9 @@ define(
                 function refresh() {
                     var domainObject = $scope.domainObject,
                         representation = lookup($scope.key, domainObject),
-                        uses = ((representation || {}).uses || []);
-
-                    // Create an empty object named "representation", for this
-                    // representation to store local variables into.
-                    $scope.representation = {};
-
-                    // Look up the actual template path, pass it to ng-include
-                    // via the "inclusion" field
-                    changeTemplate(representation && getPath(representation));
+                        path = representation && getPath(representation),
+                        uses = ((representation || {}).uses || []),
+                        canRepresent = !!(path && domainObject);
 
                     // Any existing representers are no longer valid; release them.
                     destroyRepresenters();
@@ -179,9 +169,17 @@ define(
                         delete $scope[property];
                     });
 
+                    // Create an empty object named "representation", for this
+                    // representation to store local variables into.
+                    $scope.representation = {};
+
+                    // Change templates (passing in undefined to clear
+                    // if we don't have enough info to show a template.)
+                    changeTemplate(canRepresent ? path : undefined);
+
                     // Populate scope with fields associated with the current
                     // domain object (if one has been passed in)
-                    if (domainObject) {
+                    if (canRepresent) {
                         // Track how many representations we've made in this scope,
                         // to ensure that the correct representations are matched to
                         // the correct object/key pairs.
@@ -232,12 +230,6 @@ define(
             }
 
             return {
-                transclude: 'element',
-
-                priority: 601,
-
-                terminal: true,
-
                 // Only applicable at the element level
                 restrict: "E",
 
diff --git a/platform/representation/src/TemplateLinker.js b/platform/representation/src/TemplateLinker.js
index c3f8eb0208..0c5e76cca7 100644
--- a/platform/representation/src/TemplateLinker.js
+++ b/platform/representation/src/TemplateLinker.js
@@ -60,33 +60,31 @@ define(
          * @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,
+        TemplateLinker.prototype.link = function (scope, element) {
+            var activeElement = element,
                 activeTemplateUrl,
+                comment = this.$compile('<!-- hidden mct element -->')(scope),
                 self = this;
 
             function removeElement() {
-                if (activeElement !== originalElement) {
-                    activeElement.replaceWith(originalElement);
-                    activeElement = originalElement;
+                if (activeElement !== comment) {
+                    activeElement.replaceWith(comment);
+                    activeElement = comment;
                 }
             }
 
-            function replaceElement(clone, template) {
-                activeElement.replaceWith(clone);
-                activeElement = clone;
+            function replaceElement(template) {
+                activeElement.replaceWith(element);
+                activeElement = element;
                 activeElement.empty();
                 template(scope, function (innerClone) {
-                    clone.append(innerClone);
+                    element.append(innerClone);
                 });
             }
 
             function applyTemplate(template) {
                 if (template) {
-                    transclude(function (clone) {
-                        replaceElement(clone, template);
-                    });
+                    replaceElement(template);
                 } else {
                     removeElement();
                 }
@@ -103,6 +101,8 @@ define(
                 }
             }
 
+            removeElement();
+
             return changeTemplate;
         };