feat(directive-injector): introduce getFromParent[byKey] methods on DirectiveInjector

First step towards deprecating injector.parent access.

The reason for the deprecation is that performing injector.parent.get
without keeping track of current injector.appInjector is usually wrong
(since the fallback would be injector.parent.appInjector).

Author: rkirov

lib/core_dom/directive_injector.dart

@@ -100,7 +100,7 @@ class DirectiveInjector implements DirectiveBinder {
       , KEEP_ME_LAST
       ];
 
-  final DirectiveInjector parent;
+  final DirectiveInjector _parent;
   final Injector appInjector;
   final Node _node;
   final NodeAttrs _nodeAttrs;
@@ -122,6 +122,9 @@ class DirectiveInjector implements DirectiveBinder {
   Key _key8 = null; dynamic _obj8; List<Key> _pKeys8; Function _factory8;
   Key _key9 = null; dynamic _obj9; List<Key> _pKeys9; Function _factory9;
 
+  @Deprecated("Deprecated. Use getFromParent instead.")
+  Object get parent => this._parent;
+
   static _toVisId(Visibility v) => identical(v, Visibility.LOCAL)
       ? VISIBILITY_LOCAL
       : (identical(v, Visibility.CHILDREN) ? VISIBILITY_CHILDREN : VISIBILITY_DIRECT_CHILD);
@@ -140,12 +143,12 @@ class DirectiveInjector implements DirectiveBinder {
 
   static Binding _tempBinding = new Binding();
 
-  DirectiveInjector(parent, appInjector, this._node, this._nodeAttrs, this._eventHandler,
-                    this.scope, this._animate)
+  DirectiveInjector(DirectiveInjector parent, Injector appInjector, this._node, this._nodeAttrs,
+      this._eventHandler, this.scope, this._animate)
       : appInjector = appInjector,
-        parent = parent == null ? new DefaultDirectiveInjector(appInjector) : parent;
+        _parent = parent == null ? new DefaultDirectiveInjector(appInjector) : parent;
 
-  DirectiveInjector._default(this.parent, this.appInjector)
+  DirectiveInjector._default(this._parent, this.appInjector)
       : _node = null,
         _nodeAttrs = null,
         _eventHandler = null,
@@ -193,6 +196,7 @@ class DirectiveInjector implements DirectiveBinder {
   }
 
   Object get(Type type) => getByKey(new Key(type));
+  Object getFromParent(Type type) => _parent.get(type);
 
   Object getByKey(Key key) {
     var oldTag = _TAG_GET.makeCurrent();
@@ -205,6 +209,7 @@ class DirectiveInjector implements DirectiveBinder {
       oldTag.makeCurrent();
     }
   }
+  Object getFromParentByKey(Key key) => _parent.getByKey(key);
 
   Object _getByKey(Key key) {
     int uid = key.uid;
@@ -228,12 +233,12 @@ class DirectiveInjector implements DirectiveBinder {
     } while (false);
     switch (visType) {
       case VISIBILITY_LOCAL:                  return appInjector.getByKey(k);
-      case VISIBILITY_DIRECT_CHILD:           return parent._getDirectiveByKey(k, VISIBILITY_LOCAL, i);
-      case VISIBILITY_CHILDREN:               return parent._getDirectiveByKey(k, VISIBILITY_CHILDREN, i);
+      case VISIBILITY_DIRECT_CHILD:           return _parent._getDirectiveByKey(k, VISIBILITY_LOCAL, i);
+      case VISIBILITY_CHILDREN:               return _parent._getDirectiveByKey(k, VISIBILITY_CHILDREN, i);
       // SHADOW
-      case VISIBILITY_COMPONENT_LOCAL:        return parent._getDirectiveByKey(k, VISIBILITY_LOCAL, i);
-      case VISIBILITY_COMPONENT_DIRECT_CHILD: return parent._getDirectiveByKey(k, VISIBILITY_DIRECT_CHILD, i);
-      case VISIBILITY_COMPONENT_CHILDREN:     return parent._getDirectiveByKey(k, VISIBILITY_CHILDREN, i);
+      case VISIBILITY_COMPONENT_LOCAL:        return _parent._getDirectiveByKey(k, VISIBILITY_LOCAL, i);
+      case VISIBILITY_COMPONENT_DIRECT_CHILD: return _parent._getDirectiveByKey(k, VISIBILITY_DIRECT_CHILD, i);
+      case VISIBILITY_COMPONENT_CHILDREN:     return _parent._getDirectiveByKey(k, VISIBILITY_CHILDREN, i);
       default: throw null;
     }
   }
@@ -265,7 +270,7 @@ class DirectiveInjector implements DirectiveBinder {
       case ELEMENT_PROBE_KEY_ID:      return elementProbe;
       case NG_ELEMENT_KEY_ID:         return ngElement;
       case EVENT_HANDLER_KEY_ID:      return _eventHandler;
-      case CONTENT_PORT_KEY_ID:       return parent._getById(keyId);
+      case CONTENT_PORT_KEY_ID:       return _parent._getById(keyId);
       default: new NoProviderError(_KEYS[keyId]);
     }
   }
@@ -324,7 +329,7 @@ class DirectiveInjector implements DirectiveBinder {
 
   ElementProbe get elementProbe {
     if (_elementProbe == null) {
-      ElementProbe parentProbe = parent is DirectiveInjector ? parent.elementProbe : null;
+      ElementProbe parentProbe = _parent == null ? null : _parent.elementProbe;
       _elementProbe = new ElementProbe(parentProbe, _node, this, scope);
     }
     return _elementProbe;
@@ -355,7 +360,7 @@ class TemplateDirectiveInjector extends DirectiveInjector {
       case VIEW_PORT_KEY_ID: return ((_viewPort) == null) ?
             _viewPort = new ViewPort(this, scope, _node, _animate) : _viewPort;
       case BOUND_VIEW_FACTORY_KEY_ID: return (_boundViewFactory == null) ?
-            _boundViewFactory = _viewFactory.bind(this.parent) : _boundViewFactory;
+            _boundViewFactory = _viewFactory.bind(_parent) : _boundViewFactory;
       default: return super._getById(keyId);
     }
   }
@@ -411,8 +416,7 @@ class ShadowDomComponentDirectiveInjector extends ComponentDirectiveInjector {
 
   ElementProbe get elementProbe {
     if (_elementProbe == null) {
-      ElementProbe parentProbe =
-        parent is DirectiveInjector ? parent.elementProbe : parent.getByKey(ELEMENT_PROBE_KEY);
+      ElementProbe parentProbe = _parent == null ? null : _parent.elementProbe;
       _elementProbe = new ElementProbe(parentProbe, _shadowRoot, this, scope);
     }
     return _elementProbe;
@@ -427,7 +431,7 @@ class DefaultDirectiveInjector extends DirectiveInjector {
 
   Object getByKey(Key key) => appInjector.getByKey(key);
   _getDirectiveByKey(Key key, int visType, Injector i) =>
-    parent == null ? i.getByKey(key) : parent._getDirectiveByKey(key, visType, i);
+      _parent == null ? i.getByKey(key) : _parent._getDirectiveByKey(key, visType, i);
   _getById(int keyId) {
     switch (keyId) {
       case CONTENT_PORT_KEY_ID: return null;

lib/directive/ng_control.dart

@@ -41,7 +41,7 @@ abstract class NgControl implements AttachAware, DetachAware {
 
   NgControl(NgElement this._element, DirectiveInjector injector,
       Animate this._animate)
-      : _parentControl = injector.parent.getByKey(NG_CONTROL_KEY);
+      : _parentControl = injector.getFromParentByKey(NG_CONTROL_KEY);
 
   @override
   void attach() {

lib/routing/ng_bind_route.dart

@@ -38,7 +38,7 @@ class NgBindRoute implements RouteProvider {
   NgBindRoute(this._router, this._injector, NgRoutingHelper _);
 
   /// Returns the parent [RouteProvider].
-  RouteProvider get _parent => _injector.parent.getByKey(ROUTE_PROVIDER_KEY);
+  RouteProvider get _parent => _injector.getFromParentByKey(ROUTE_PROVIDER_KEY);
 
   Route get route => routeName.startsWith('.') ?
       _parent.route.getRoute(routeName.substring(1)) :

lib/routing/ng_view.dart

@@ -76,7 +76,7 @@ class NgView implements DetachAware, RouteProvider {
       : _dirInjector = dirInjector,
         _locationService = dirInjector.getByKey(NG_ROUTING_HELPER_KEY)
   {
-    RouteProvider routeProvider = dirInjector.parent.getByKey(NG_VIEW_KEY);
+    RouteProvider routeProvider = dirInjector.getFromParentByKey(NG_VIEW_KEY);
     _route = routeProvider != null ?
         routeProvider.route.newHandle() :
         router.root.newHandle();

test/core_dom/directive_injector_spec.dart

@@ -2,6 +2,7 @@ library directive_injector_spec;
 
 import '../_specs.dart';
 import 'package:angular/core_dom/directive_injector.dart';
+import 'package:angular/core_dom/static_keys.dart';
 
 void main() {
   describe('DirectiveInjector', () {
@@ -33,7 +34,6 @@ void main() {
       });
 
       it('should return basic types', () {
-        expect(injector.parent is DefaultDirectiveInjector).toBe(true);
         expect(injector.appInjector).toBe(appInjector);
         expect(injector.scope).toBe(scope);
         expect(injector.get(Injector)).toBe(appInjector);
@@ -47,6 +47,16 @@ void main() {
         expect((injector.get(ElementProbe) as ElementProbe).element).toBe(div);
       });
 
+      it('should support get from parent methods', () {
+        var newDiv = new DivElement();
+        var childInjector = new DirectiveInjector(
+            injector, appInjector, newDiv, new NodeAttrs(newDiv), eventHandler, scope, animate);
+
+        expect(childInjector.get(Node)).toBe(newDiv);
+        expect(childInjector.getFromParent(Node)).toBe(div);
+        expect(childInjector.getFromParentByKey(NODE_KEY)).toBe(div);
+      });
+
       it('should instantiate types', () {
         addDirective(_Type9);
         addDirective(_Type8);