feat(angular): push/setRoot/pop

angular/src/directives/navigation/go-back.ts

@@ -1,5 +1,5 @@
 import { Directive, HostListener } from '@angular/core';
-import { NavController } from '../../providers/nav-controller';
+import { NavController, NavIntent } from '../../providers/nav-controller';
 
 @Directive({
   selector: '[goBack]',
@@ -12,6 +12,6 @@ export class GoBack {
 
   @HostListener('click')
   onClick() {
-    this.navCtrl.setGoback();
+    this.navCtrl.setIntent(NavIntent.Back);
   }
 }

angular/src/directives/navigation/ion-back-button.ts

@@ -1,6 +1,6 @@
 import { Directive, ElementRef, HostListener, Input, Optional } from '@angular/core';
 import { Router } from '@angular/router';
-import { NavController } from '../../providers/nav-controller';
+import { NavController, NavIntent } from '../../providers/nav-controller';
 import { IonRouterOutlet } from './ion-router-outlet';
 
 @Directive({
@@ -29,7 +29,7 @@ export class IonBackButton {
       this.routerOutlet.pop();
       ev.preventDefault();
     } else if (this.router && this.defaultHref != null) {
-      this.navCtrl.setGoback();
+      this.navCtrl.setIntent(NavIntent.Back);
       this.router.navigateByUrl(this.defaultHref);
       ev.preventDefault();
     }

angular/src/providers/nav-controller.ts

@@ -1,14 +1,41 @@
-import { Injectable } from '@angular/core';
+import { Injectable, Optional } from '@angular/core';
+import { NavigationExtras, Router, UrlTree } from '@angular/router';
+
+export const enum NavIntent {
+  Auto,
+  Forward,
+  Back,
+  Root
+}
 
 @Injectable()
 export class NavController {
 
   private direction = 0;
-  private goBack = false;
+  private intent: NavIntent = NavIntent.Auto;
   private stack: string[] = [];
 
-  setGoback() {
-    this.goBack = true;
+  constructor(
+    @Optional() private router?: Router
+  ) {}
+
+  goForward(url: string | UrlTree, extras?: NavigationExtras) {
+    this.intent = NavIntent.Forward;
+    return this.router.navigateByUrl(url, extras);
+  }
+
+  goBack(url: string | UrlTree, extras?: NavigationExtras) {
+    this.intent = NavIntent.Back;
+    return this.router.navigateByUrl(url, extras);
+  }
+
+  goRoot(url: string | UrlTree, extras?: NavigationExtras) {
+    this.intent = NavIntent.Root;
+    return this.router.navigateByUrl(url, extras);
+  }
+
+  setIntent(intent: NavIntent) {
+    this.intent = intent;
   }
 
   consumeDirection() {
@@ -23,12 +50,17 @@ export class NavController {
       }
     }
 
-    const direction = this.goBack
-      ? -1
-      : this.direction;
+    const direction = directionForIntent(this.intent, this.direction);
 
-    this.goBack = false;
+    this.intent = NavIntent.Auto;
     this.direction = 0;
     return direction;
   }
 }
+
+function directionForIntent(intent: NavIntent, nav: number): number {
+  if (intent === NavIntent.Auto) {
+    return nav;
+  }
+  return intent === NavIntent.Back ? -1 : 1;
+}