fix(ngSwitch): not leak when transcluded and cloned

The leak can occur when ngSwich is used inside ngRepeat or any other
directive which does not attached transcluded content to DOM but clones
it.

Refactor ngSwitch to use controller instead of storing data on compile
node.

Closes angular#1621

Author: danilsomsikov

src/ng/directive/ngSwitch.js

@@ -62,51 +62,52 @@
 var NG_SWITCH = 'ng-switch';
 var ngSwitchDirective = valueFn({
   restrict: 'EA',
-  compile: function(element, attr) {
+  require: 'ngSwitch',
+  controller: function ngSwitchController() {
+    this.cases = {};
+  },
+  link: function(scope, element, attr, ctrl) {
     var watchExpr = attr.ngSwitch || attr.on,
-        cases = {};
+        selectedTransclude,
+        selectedElement,
+        selectedScope;
 
-    element.data(NG_SWITCH, cases);
-    return function(scope, element){
-      var selectedTransclude,
-          selectedElement,
-          selectedScope;
-
-      scope.$watch(watchExpr, function ngSwitchWatchAction(value) {
-        if (selectedElement) {
-          selectedScope.$destroy();
-          selectedElement.remove();
-          selectedElement = selectedScope = null;
-        }
-        if ((selectedTransclude = cases['!' + value] || cases['?'])) {
-          scope.$eval(attr.change);
-          selectedScope = scope.$new();
-          selectedTransclude(selectedScope, function(caseElement) {
-            selectedElement = caseElement;
-            element.append(caseElement);
-          });
-        }
-      });
-    };
+    scope.$watch(watchExpr, function ngSwitchWatchAction(value) {
+      if (selectedElement) {
+        selectedScope.$destroy();
+        selectedElement.remove();
+        selectedElement = selectedScope = null;
+      }
+      if ((selectedTransclude = ctrl.cases['!' + value] || ctrl.cases['?'])) {
+        scope.$eval(attr.change);
+        selectedScope = scope.$new();
+        selectedTransclude(selectedScope, function(caseElement) {
+          selectedElement = caseElement;
+          element.append(caseElement);
+        });
+      }
+    });
   }
 });
 
 var ngSwitchWhenDirective = ngDirective({
   transclude: 'element',
   priority: 500,
-  compile: function(element, attrs, transclude) {
-    var cases = element.inheritedData(NG_SWITCH);
-    assertArg(cases);
-    cases['!' + attrs.ngSwitchWhen] = transclude;
+  require: '^ngSwitch',
+  compile: function(element, attrs, transclude, ctrl) {
+    return function(scope, element, attr, ctrl) {
+      ctrl.cases['!' + attrs.ngSwitchWhen] = transclude;
+    };
   }
 });
 
 var ngSwitchDefaultDirective = ngDirective({
   transclude: 'element',
   priority: 500,
-  compile: function(element, attrs, transclude) {
-    var cases = element.inheritedData(NG_SWITCH);
-    assertArg(cases);
-    cases['?'] = transclude;
+  require: '^ngSwitch',
+  compile: function(element, attrs, transclude, ctrl) {
+    return function(scope, element, attr, ctrl) {
+      ctrl.cases['?'] = transclude;
+    };
   }
 });

test/ng/directive/ngSwitchSpec.js

@@ -90,4 +90,16 @@ describe('ngSwitch', function() {
     expect(child2).toBeDefined();
     expect(child2).not.toBe(child1);
   }));
+
+
+  it('should not leak when comiled node is not attached to DOM but cloned',
+      inject(function($rootScope, $compile) {
+    element = $compile(
+      '<div ng-repeat="i in []">' +
+        '<ng-switch on="url">' +
+          '<div ng-switch-when="a">{{name}}</div>' +
+        '</ng-switch>' +
+      '</div>')($rootScope);
+    $rootScope.$apply();
+  }));
 });