Fix container view hooks

packages/ember-htmlbars/tests/integration/will-destroy-element-hook-test.js

@@ -0,0 +1,57 @@
+import run from 'ember-metal/run_loop';
+import Component from 'ember-views/views/component';
+import compile from 'ember-template-compiler/system/compile';
+import { runAppend, runDestroy } from "ember-runtime/tests/utils";
+
+import { set } from 'ember-metal/property_set';
+
+var component;
+
+QUnit.module('ember-htmlbars: destroy-element-hook tests', {
+  teardown() {
+    runDestroy(component);
+  }
+});
+
+QUnit.test('willDestroyElement is only called once when a component leaves scope', function(assert) {
+  var innerChild, innerChildDestroyed;
+
+  component = Component.create({
+    switch: true,
+
+    layout: compile(`
+     {{~#if switch~}}
+       {{~#view innerChild}}Truthy{{/view~}}
+     {{~/if~}}
+    `),
+
+    innerChild: Component.extend({
+      init() {
+        this._super(...arguments);
+        innerChild = this;
+      },
+
+      willDestroyElement() {
+        if (innerChildDestroyed) {
+          throw new Error('willDestroyElement has already been called!!');
+        } else {
+          innerChildDestroyed = true;
+        }
+      }
+    })
+  });
+
+  runAppend(component);
+
+  assert.equal(component.$().text(), 'Truthy', 'precond - truthy template is displayed');
+  assert.equal(component.get('childViews.length'), 1);
+
+  run(function() {
+    set(component, 'switch', false);
+  });
+
+  run(function() {
+    assert.equal(innerChild.get('isDestroyed'), true, 'the innerChild has been destroyed');
+    assert.equal(component.$().text(), '', 'truthy template is removed');
+  });
+});

packages/ember-metal-views/lib/renderer.js

@@ -231,14 +231,7 @@ Renderer.prototype.willDestroyElement = function (view) {
   }
 
   if (view._transitionTo) {
-    view._transitionTo('destroying', false);
-  }
-
-  var childViews = view.childViews;
-  if (childViews) {
-    for (var i = 0; i < childViews.length; i++) {
-      this.willDestroyElement(childViews[i]);
-    }
+    view._transitionTo('destroying');
   }
 };
 
@@ -253,11 +246,8 @@ Renderer.prototype.didDestroyElement = function (view) {
     view._transitionTo('preRender');
   }
 
-  var childViews = view.childViews;
-  if (childViews) {
-    for (var i = 0; i < childViews.length; i++) {
-      this.didDestroyElement(childViews[i]);
-    }
+  if (view.trigger) {
+    view.trigger('didDestroyElement');
   }
 }; // element destroyed so view.destroy shouldn't try to remove it removedFromDOM
 

packages/ember-views/lib/mixins/view_state_support.js

@@ -2,12 +2,12 @@ import Ember from 'ember-metal/core';
 import { Mixin } from "ember-metal/mixin";
 
 var ViewStateSupport = Mixin.create({
-  transitionTo(state, children) {
+  transitionTo(state) {
     Ember.deprecate("Ember.View#transitionTo has been deprecated, it is for internal use only");
-    this._transitionTo(state, children);
+    this._transitionTo(state);
   },
 
-  _transitionTo(state, children) {
+  _transitionTo(state) {
     var priorState = this.currentState;
     var currentState = this.currentState = this._states[state];
     this._state = state;

packages/ember-views/lib/views/container_view.js

@@ -9,6 +9,7 @@ import {
   observer,
   beforeObserver
 } from "ember-metal/mixin";
+import { on } from "ember-metal/events";
 
 import containerViewTemplate from "ember-htmlbars/templates/container-view";
 containerViewTemplate.meta.revision = 'Ember@VERSION_STRING_PLACEHOLDER';
@@ -280,8 +281,26 @@ var ContainerView = View.extend(MutableArray, {
   },
 
   objectAt(idx) {
-    return get(this, 'childViews')[idx];
-  }
+    return this.childViews[idx];
+  },
+
+  _triggerChildWillDestroyElement: on('willDestroyElement', function () {
+    var childViews = this.childViews;
+    if (childViews) {
+      for (var i = 0; i < childViews.length; i++) {
+        this.renderer.willDestroyElement(childViews[i]);
+      }
+    }
+  }),
+
+  _triggerChildDidDestroyElement: on('didDestroyElement', function () {
+    var childViews = this.childViews;
+    if (childViews) {
+      for (var i = 0; i < childViews.length; i++) {
+        this.renderer.didDestroyElement(childViews[i]);
+      }
+    }
+  })
 });
 
 export default ContainerView;