feat(query): initial implementation of view query.

ViewQuery is a new API that allows a component to query its view.

Closes #1935

modules/angular2/src/core/annotations/decorators.ts

@@ -1,6 +1,6 @@
 import {ComponentAnnotation, DirectiveAnnotation, LifecycleEvent} from './annotations';
 import {ViewAnnotation} from './view';
-import {AttributeAnnotation, QueryAnnotation} from './di';
+import {AttributeAnnotation, QueryAnnotation, ViewQueryAnnotation} from './di';
 import {
   makeDecorator,
   makeParamDecorator,
@@ -368,3 +368,9 @@ export var Attribute: AttributeFactory = makeParamDecorator(AttributeAnnotation)
  * {@link Query} factory function.
  */
 export var Query: QueryFactory = makeParamDecorator(QueryAnnotation);
+
+
+/**
+ * {@link ViewQuery} factory function.
+ */
+export var ViewQuery: QueryFactory = makeParamDecorator(ViewQueryAnnotation);

modules/angular2/src/core/annotations/di.ts

@@ -1,4 +1,5 @@
 export {
   Query as QueryAnnotation,
+  ViewQuery as ViewQueryAnnotation,
   Attribute as AttributeAnnotation,
 } from '../annotations_impl/di';

modules/angular2/src/core/annotations_impl/di.ts

@@ -57,6 +57,8 @@ export class Query extends DependencyMetadata {
     this.descendants = descendants;
   }
 
+  get isViewQuery() { return false; }
+
   get selector() { return resolveForwardRef(this._selector); }
 
   get isVarBindingQuery(): boolean { return isString(this.selector); }
@@ -65,3 +67,20 @@ export class Query extends DependencyMetadata {
 
   toString(): string { return `@Query(${stringify(this.selector)})`; }
 }
+
+/**
+ * Specifies that a {@link QueryList} should be injected.
+ *
+ * See {@link QueryList} for usage and example.
+ *
+ * @exportedAs angular2/annotations
+ */
+@CONST()
+export class ViewQuery extends Query {
+  constructor(_selector: Type | string, {descendants = false}: {descendants?: boolean} = {}) {
+    super(_selector, {descendants: descendants});
+  }
+
+  get isViewQuery() { return true; }
+  toString(): string { return `@ViewQuery(${stringify(this.selector)})`; }
+}

modules/angular2/src/core/compiler/base_query_list.dart

@@ -45,4 +45,9 @@ class BaseQueryList<T> extends Object with IterableMixin<T> {
   get length => _results.length;
   get first => _results.first;
   get last => _results.last;
+
+  List map(fn(T)) {
+    // Note: we need to return a list instead of iterable to match JS.
+    return this._results.map(fn).toList();
+  }
 }

modules/angular2/src/core/compiler/base_query_list.ts

@@ -38,4 +38,6 @@ export class BaseQueryList<T> {
   get length() { return this._results.length; }
   get first() { return ListWrapper.first(this._results); }
   get last() { return ListWrapper.last(this._results); }
+
+  map<U>(fn: (T) => U): U[] { return this._results.map(fn); }
 }

modules/angular2/src/core/compiler/element_injector.ts

@@ -434,7 +434,7 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
   private _preBuiltObjects = null;
 
   // Queries are added during construction or linking with a new parent.
-  // They are never removed.
+  // They are removed only through unlinking.
   private _query0: QueryRef;
   private _query1: QueryRef;
   private _query2: QueryRef;
@@ -487,6 +487,10 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
 
     this._hydrateInjector(imperativelyCreatedInjector, host);
 
+    if (isPresent(host)) {
+      this._addViewQueries(host);
+    }
+
     this._addDirectivesToQueries();
     this._addVarBindingsToQueries();
 
@@ -650,6 +654,22 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
     }
   }
 
+  private _addViewQueries(host: ElementInjector): void {
+    if (isPresent(host._query0) && host._query0.originator == host)
+      this._addViewQuery(host._query0);
+    if (isPresent(host._query1) && host._query1.originator == host)
+      this._addViewQuery(host._query1);
+    if (isPresent(host._query2) && host._query2.originator == host)
+      this._addViewQuery(host._query2);
+  }
+
+  private _addViewQuery(queryRef: QueryRef): void {
+    // TODO(rado): Replace this.parent check with distanceToParent = 1 when
+    // https://github.com/angular/angular/issues/2707 is fixed.
+    if (!queryRef.query.descendants && isPresent(this.parent)) return;
+    this._assignQueryRef(queryRef);
+  }
+
   private _addVarBindingsToQueries(): void {
     this._addVarBindingsToQuery(this._query0);
     this._addVarBindingsToQuery(this._query1);
@@ -733,15 +753,15 @@ export class ElementInjector extends TreeNode<ElementInjector> implements Depend
 
   private _addParentQueries(): void {
     if (isBlank(this.parent)) return;
-    if (isPresent(this.parent._query0)) {
+    if (isPresent(this.parent._query0) && !this.parent._query0.query.isViewQuery) {
       this._addQueryToTree(this.parent._query0);
       if (this.hydrated) this.parent._query0.update();
     }
-    if (isPresent(this.parent._query1)) {
+    if (isPresent(this.parent._query1) && !this.parent._query1.query.isViewQuery) {
       this._addQueryToTree(this.parent._query1);
       if (this.hydrated) this.parent._query1.update();
     }
-    if (isPresent(this.parent._query2)) {
+    if (isPresent(this.parent._query2) && !this.parent._query2.query.isViewQuery) {
       this._addQueryToTree(this.parent._query2);
       if (this.hydrated) this.parent._query2.update();
     }