fix(md-menu): allow nested md-menu-content (#11103)

Author: Florian Scholz

src/components/menu/js/menuDirective.js

@@ -179,8 +179,6 @@ function MenuDirective($mdUtil) {
     templateElement.addClass('md-menu');
 
     var triggerEl = templateElement.children()[0];
-    var contentEl = templateElement.children()[1];
-
     var prefixer = $mdUtil.prefixer();
 
     if (!prefixer.hasAttribute(triggerEl, 'ng-click')) {
@@ -198,8 +196,8 @@ function MenuDirective($mdUtil) {
       throw Error(INVALID_PREFIX + 'Expected the menu to have a trigger element.');
     }
 
-    if (!contentEl || contentEl.nodeName !== 'MD-MENU-CONTENT') {
-      throw Error(INVALID_PREFIX + 'Expected the menu to contain a `md-menu-content` element.');
+    if (templateElement.children().length !== 2) {
+      throw Error(INVALID_PREFIX + 'Expected two children elements. The second element must have a `md-menu-content` element.');
     }
 
     // Default element for ARIA attributes has the ngClick or ngMouseenter expression

src/components/menu/menu.spec.js

@@ -51,6 +51,21 @@ describe('material.components.menu', function() {
       expect(createInvalidMenu).toThrow();
     }));
 
+    it('nested md-menu-content should be allowed', inject(function($compile, $rootScope) {
+        function createValidMenu() {
+            $compile(
+                '<md-menu>' +
+                '  <button ng-click="null">Trigger Element</button>' +
+                '  <some-custom-element>' +
+                '    <md-menu-content>Menu Content</md-menu-content>' +
+                '  </some-custom-element>' +
+                '</md-menu>'
+            )($rootScope);
+        }
+
+        expect(createValidMenu).not.toThrow();
+    }));
+
     it('specifies button type', inject(function($compile, $rootScope) {
       var menu = setup()[0];
       expect(menu.firstElementChild.getAttribute('type')).toBe('button');