docs(query): edit and extend query and view query docs.

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

@@ -50,34 +50,191 @@ export class AttributeMetadata extends DependencyMetadata {
 }
 
 /**
- * Specifies that a {@link QueryList} should be injected.
+ * Declares an injectable parameter to be a live list of directives or variable
+ * bindings from the content children of a directive.
  *
- * See {@link QueryList} for usage and example.
+ * ### Example ([live demo](http://plnkr.co/edit/lY9m8HLy7z06vDoUaSN2?p=preview))
+ *
+ * Assume that `<tabs>` component would like to get a list its children `<pane>`
+ * components as shown in this example:
+ *
+ * ```html
+ * <tabs>
+ *   <pane title="Overview">...</pane>
+ *   <pane *ng-for="#o of objects" [title]="o.title">{{o.text}}</pane>
+ * </tabs>
+ * ```
+ *
+ * The preferred solution is to query for `Pane` directives using this decorator.
+ *
+ * ```javascript
+ * @Component({
+ *   selector: 'pane',
+ *   properties: ['title']
+ * })
+ * @View(...)
+ * class Pane {
+ *   title:string;
+ * }
+ *
+ * @Component({
+ *   selector: 'tabs'
+ * })
+ * @View({
+ *  template: `
+ *    <ul>
+ *      <li *ng-for="#pane of panes">{{pane.title}}</li>
+ *    </ul>
+ *    <content></content>
+ *  `
+ * })
+ * class Tabs {
+ *   panes: QueryList<Pane>;
+ *   constructor(@Query(Pane) panes:QueryList<Pane>) {
+  *    this.panes = panes;
+  *  }
+ * }
+ * ```
+ *
+ * A query can look for variable bindinds by passing in a string with desired binding symbol.
+ *
+ * ### Example ([live demo](http://plnkr.co/edit/sT2j25cH1dURAyBRCKx1?p=preview))
+ * ```html
+ * <seeker>
+ *   <div #findme>...</div>
+ * </seeker>
+ *
+ * @Component({
+ *   selector: 'foo'
+ * })
+ * @View(...)
+ * class seeker {
+ *   constructor(@Query('findme') elList: QueryList<ElementRef>) {...}
+ * }
+ * ```
+ *
+ * In this case the object that is injected depend on the type of the variable
+ * binding. It can be an ElementRef, a directive or a component.
+ *
+ * Passing in a comma separated list of variable bindings will query for all of them.
+ *
+ * ```html
+ * <seeker>
+ *   <div #find-me>...</div>
+ *   <div #find-me-too>...</div>
+ * </seeker>
+ *
+ *  @Component({
+ *   selector: 'foo'
+ * })
+ * @View(...)
+ * class Seeker {
+ *   constructor(@Query('findMe, findMeToo') elList: QueryList<ElementRef>) {...}
+ * }
+ * ```
+ *
+ * Configure whether query looks for direct children or all descendants
+ * of the querying element, by using the `descendants` parameter.
+ * It is set to `false` by default.
+ *
+ * ### Example ([live demo](http://plnkr.co/edit/wtGeB977bv7qvA5FTYl9?p=preview))
+ * ```html
+ * <container #first>
+ *   <item>a</item>
+ *   <item>b</item>
+ *   <container #second>
+ *     <item>c</item>
+ *   </container>
+ * </container>
+ * ```
+ *
+ * When querying for items, the first container will see only `a` and `b` by default,
+ * but with `Query(TextDirective, {descendants: true})` it will see `c` too.
+ *
+ * The queried directives are kept in a depth-first pre-order with respect to their
+ * positions in the DOM.
+ *
+ * Query does not look deep into any subcomponent views.
+ *
+ * Query is updated as part of the change-detection cycle. Since change detection
+ * happens after construction of a directive, QueryList will always be empty when observed in the
+ * constructor.
+ *
+ * The injected object is an unmodifiable live list.
+ * See {@link QueryList} for more details.
  */
 @CONST()
 export class QueryMetadata extends DependencyMetadata {
+  /**
+   * whether we want to query only direct children (false) or all
+   * children (true).
+   */
   descendants: boolean;
+
   constructor(private _selector: Type | string,
               {descendants = false}: {descendants?: boolean} = {}) {
     super();
     this.descendants = descendants;
   }
 
-  get isViewQuery() { return false; }
+  /**
+   * always `false` to differentiate it with {@link ViewQueryMetadata}.
+   */
+  get isViewQuery(): boolean { return false; }
 
+  /**
+   * what this is querying for.
+   */
   get selector() { return resolveForwardRef(this._selector); }
 
+  /**
+   * whether this is querying for a variable binding or a directive.
+   */
   get isVarBindingQuery(): boolean { return isString(this.selector); }
 
+  /**
+   * returns a list of variable bindings this is querying for.
+   * Only applicable if this is a variable bindings query.
+   */
   get varBindings(): string[] { return StringWrapper.split(this.selector, new RegExp(",")); }
 
   toString(): string { return `@Query(${stringify(this.selector)})`; }
 }
 
 /**
+ * Similar to {@link QueryMetadata}, but querying the component view, instead of
+ * the content children.
+ *
+ * ### Example ([live demo](http://plnkr.co/edit/eNsFHDf7YjyM6IzKxM1j?p=preview))
+ *
+ * ```javascript
+ * @Component({...})
+ * @View({
+ *   template: `
+ *     <item> a </item>
+ *     <item> b </item>
+ *     <item> c </item>
+ *   `
+ * })
+ * class MyComponent {
+ *   shown: boolean;
+ *
+ *   constructor(private @Query(Item) items:QueryList<Item>) {
+ *     items.onChange(() => console.log(items.length));
+ *   }
+ * }
+ * ```
+ *
+ * Supports the same querying parameters as {@link QueryMetadata}, except
+ * `descendants`. This always queries the whole view.
+ *
+ * As `shown` is flipped between true and false, items will contain zero of one
+ * items.
+ *
  * Specifies that a {@link QueryList} should be injected.
  *
- * See {@link QueryList} for usage and example.
+ * The injected object is an iterable and observable live list.
+ * See {@link QueryList} for more details.
  */
 @CONST()
 export class ViewQueryMetadata extends QueryMetadata {
@@ -85,6 +242,9 @@ export class ViewQueryMetadata extends QueryMetadata {
     super(_selector, {descendants: descendants});
   }
 
+  /**
+   * always `true` to differentiate it with {@link QueryMetadata}.
+   */
   get isViewQuery() { return true; }
   toString(): string { return `@ViewQuery(${stringify(this.selector)})`; }
 }