fix(router): apply APP_BASE_HREF when using PathLocationStrategy

Correctly initializes APP_BASE_HREF, and falls back to the `<base>` tag in the absence
of an APP_BASE_HREF provider.

Closes #5028

modules/angular2/src/router/location.ts

@@ -1,40 +1,6 @@
 import {LocationStrategy} from './location_strategy';
-import {StringWrapper, isPresent, CONST_EXPR} from 'angular2/src/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/facade/async';
-import {isBlank} from 'angular2/src/facade/lang';
-import {BaseException, WrappedException} from 'angular2/src/facade/exceptions';
-import {OpaqueToken, Injectable, Optional, Inject} from 'angular2/angular2';
-
-/**
- * The `APP_BASE_HREF` token represents the base href to be used with the
- * {@link PathLocationStrategy}.
- *
- * If you're using {@link PathLocationStrategy}, you must provide a provider to a string
- * representing the URL prefix that should be preserved when generating and recognizing
- * URLs.
- *
- * ### Example
- *
- * ```
- * import {Component} from 'angular2/angular2';
- * import {ROUTER_DIRECTIVES, ROUTER_PROVIDERS, RouteConfig} from 'angular2/router';
- *
- * @Component({directives: [ROUTER_DIRECTIVES]})
- * @RouteConfig([
- *  {...},
- * ])
- * class AppCmp {
- *   // ...
- * }
- *
- * bootstrap(AppCmp, [
- *   ROUTER_PROVIDERS,
- *   PathLocationStrategy,
- *   provide(APP_BASE_HREF, {useValue: '/my/app'})
- * ]);
- * ```
- */
-export const APP_BASE_HREF: OpaqueToken = CONST_EXPR(new OpaqueToken('appBaseHref'));
+import {Injectable, Inject} from 'angular2/angular2';
 
 /**
  * `Location` is a service that applications can use to interact with a browser's URL.
@@ -83,15 +49,8 @@ export class Location {
   /** @internal */
   _baseHref: string;
 
-  constructor(public platformStrategy: LocationStrategy,
-              @Optional() @Inject(APP_BASE_HREF) href?: string) {
-    var browserBaseHref = isPresent(href) ? href : this.platformStrategy.getBaseHref();
-
-    if (isBlank(browserBaseHref)) {
-      throw new BaseException(
-          `No base href set. Either provide a provider for the APP_BASE_HREF token or add a base element to the document.`);
-    }
-
+  constructor(public platformStrategy: LocationStrategy) {
+    var browserBaseHref = this.platformStrategy.getBaseHref();
     this._baseHref = stripTrailingSlash(stripIndexHtml(browserBaseHref));
     this.platformStrategy.onPopState(
         (_) => { ObservableWrapper.callNext(this._subject, {'url': this.path(), 'pop': true}); });
@@ -117,11 +76,10 @@ export class Location {
    * used, or the `APP_BASE_HREF` if the `PathLocationStrategy` is in use.
    */
   prepareExternalUrl(url: string): string {
-    if (!url.startsWith('/')) {
+    if (url.length > 0 && !url.startsWith('/')) {
       url = '/' + url;
     }
-    return this.platformStrategy.prepareExternalUrl(
-        stripTrailingSlash(_addBaseHref(this._baseHref, url)));
+    return this.platformStrategy.prepareExternalUrl(url);
   }
 
   /**
@@ -158,13 +116,6 @@ function _stripBaseHref(baseHref: string, url: string): string {
   return url;
 }
 
-function _addBaseHref(baseHref: string, url: string): string {
-  if (!url.startsWith(baseHref)) {
-    return baseHref + url;
-  }
-  return url;
-}
-
 function stripIndexHtml(url: string): string {
   if (/\/index.html$/g.test(url)) {
     // '/index.html'.length == 11

modules/angular2/src/router/location_strategy.ts

@@ -1,3 +1,6 @@
+import {CONST_EXPR} from 'angular2/src/facade/lang';
+import {OpaqueToken} from 'angular2/angular2';
+
 /**
  * `LocationStrategy` is responsible for representing and reading route state
  * from the the browser's URL. Angular provides two strategies:
@@ -24,6 +27,38 @@ export abstract class LocationStrategy {
   abstract getBaseHref(): string;
 }
 
+
+/**
+ * The `APP_BASE_HREF` token represents the base href to be used with the
+ * {@link PathLocationStrategy}.
+ *
+ * If you're using {@link PathLocationStrategy}, you must provide a provider to a string
+ * representing the URL prefix that should be preserved when generating and recognizing
+ * URLs.
+ *
+ * ### Example
+ *
+ * ```
+ * import {Component} from 'angular2/angular2';
+ * import {ROUTER_DIRECTIVES, ROUTER_PROVIDERS, RouteConfig} from 'angular2/router';
+ *
+ * @Component({directives: [ROUTER_DIRECTIVES]})
+ * @RouteConfig([
+ *  {...},
+ * ])
+ * class AppCmp {
+ *   // ...
+ * }
+ *
+ * bootstrap(AppCmp, [
+ *   ROUTER_PROVIDERS,
+ *   PathLocationStrategy,
+ *   provide(APP_BASE_HREF, {useValue: '/my/app'})
+ * ]);
+ * ```
+ */
+export const APP_BASE_HREF: OpaqueToken = CONST_EXPR(new OpaqueToken('appBaseHref'));
+
 export function normalizeQueryParams(params: string): string {
   return (params.length > 0 && params.substring(0, 1) != '?') ? ('?' + params) : params;
 }

modules/angular2/src/router/path_location_strategy.ts

@@ -1,7 +1,9 @@
 import {DOM} from 'angular2/src/core/dom/dom_adapter';
-import {Injectable} from 'angular2/angular2';
+import {Injectable, Inject} from 'angular2/angular2';
 import {EventListener, History, Location} from 'angular2/src/facade/browser';
-import {LocationStrategy, normalizeQueryParams} from './location_strategy';
+import {isBlank} from 'angular2/src/facade/lang';
+import {BaseException} from 'angular2/src/facade/exceptions';
+import {LocationStrategy, APP_BASE_HREF, normalizeQueryParams} from './location_strategy';
 
 /**
  * `PathLocationStrategy` is a {@link LocationStrategy} used to configure the
@@ -54,11 +56,21 @@ export class PathLocationStrategy extends LocationStrategy {
   private _history: History;
   private _baseHref: string;
 
-  constructor() {
+  constructor(@Inject(APP_BASE_HREF) href?: string) {
     super();
+
+    if (isBlank(href)) {
+      href = DOM.getBaseHref();
+    }
+
+    if (isBlank(href)) {
+      throw new BaseException(
+          `No base href set. Please provide a value for the APP_BASE_HREF token or add a base element to the document.`);
+    }
+
     this._location = DOM.getLocation();
     this._history = DOM.getHistory();
-    this._baseHref = DOM.getBaseHref();
+    this._baseHref = href;
   }
 
   onPopState(fn: EventListener): void {
@@ -68,12 +80,18 @@ export class PathLocationStrategy extends LocationStrategy {
 
   getBaseHref(): string { return this._baseHref; }
 
-  prepareExternalUrl(internal: string): string { return this._baseHref + internal; }
+  prepareExternalUrl(internal: string): string {
+    if (internal.startsWith('/') && this._baseHref.endsWith('/')) {
+      return this._baseHref + internal.substring(1);
+    }
+    return this._baseHref + internal;
+  }
 
   path(): string { return this._location.pathname + normalizeQueryParams(this._location.search); }
 
   pushState(state: any, title: string, url: string, queryParams: string) {
-    this._history.pushState(state, title, (url + normalizeQueryParams(queryParams)));
+    var externalUrl = this.prepareExternalUrl(url + normalizeQueryParams(queryParams));
+    this._history.pushState(state, title, externalUrl);
   }
 
   forward(): void { this._history.forward(); }