docs: adds missing api docs

modules/@angular/router/src/router_state.ts

@@ -4,10 +4,32 @@ import { Observable } from 'rxjs/Observable';
 import { BehaviorSubject } from 'rxjs/BehaviorSubject';
 import { ComponentFactory, Type } from '@angular/core';
 
+/**
+ * A collection of parameters.
+ */
 export type Params = { [key: string]: string };
 
-export const PRIMARY_OUTLET = "PRIMARY_OUTLET";
+/**
+ * Name of the primary outlet.
+ * @type {string}
+ */
+export const PRIMARY_OUTLET: string = "PRIMARY_OUTLET";
 
+/**
+ * The state of the router at a particular moment in time.
+ *
+ * ### Usage
+ *
+ * ```
+ * class MyComponent {
+ *   constructor(router: Router) {
+ *     const state = router.routerState;
+ *     const id: Observable<string> = state.firstChild(state.root).params.map(p => p.id);
+ *     const isDebug: Observable<string> = state.queryParams.map(q => q.debug);
+ *   }
+ * }
+ * ```
+ */
 export class RouterState extends Tree<ActivatedRoute> {
   constructor(root: TreeNode<ActivatedRoute>, public queryParams: Observable<Params>, public fragment: Observable<string>) {
     super(root);
@@ -19,11 +41,23 @@ export function createEmptyState(rootComponent: Type): RouterState {
   const emptyParams = new BehaviorSubject({});
   const emptyQueryParams = new BehaviorSubject({});
   const fragment = new BehaviorSubject("");
-  // TODO outlet name should not be outlet
   const activated = new ActivatedRoute(emptyUrl, emptyParams, PRIMARY_OUTLET, rootComponent, <any>null);
   return new RouterState(new TreeNode<ActivatedRoute>(activated, []), emptyQueryParams, fragment);
 }
 
+/**
+ * Contains the information about a component loaded in an outlet.
+ *
+ * ### Usage
+ *
+ * ```
+ * class MyComponent {
+ *   constructor(route: ActivatedRoute) {
+ *     const id: Observable<string> = route.params.map(p => p.id);
+ *   }
+ * }
+ * ```
+ */
 export class ActivatedRoute {
   constructor(public urlSegments: Observable<UrlSegment[]>,
               public params: Observable<Params>,