fix(tabs): popToRoot catches the rejected promise

Author: manucorporat

src/components/tabs/tabs.ts

@@ -529,12 +529,16 @@ export class Tabs extends Ion implements AfterViewInit {
 
       } else if (tab.length() > 1) {
         // if we're a few pages deep, pop to root
-        tab.popToRoot();
+        tab.popToRoot().catch(() => {
+          console.debug('Tabs: pop to root was cancelled');
+        });
 
       } else if (getComponent(this._linker, tab.root) !== active.component) {
         // Otherwise, if the page we're on is not our real root, reset it to our
         // default root type
-        tab.setRoot(tab.root);
+        tab.setRoot(tab.root).catch(() => {
+          console.debug('Tabs: reset root was cancelled');
+        });
       }
     }
   }
@@ -545,7 +549,7 @@ export class Tabs extends Ion implements AfterViewInit {
    */
   setTabbarPosition(top: number, bottom: number) {
     if (this._top !== top || this._bottom !== bottom) {
-      const tabbarEle = <HTMLElement>this._tabbar.nativeElement;
+      var tabbarEle = <HTMLElement>this._tabbar.nativeElement;
       tabbarEle.style.top = (top > -1 ? top + 'px' : '');
       tabbarEle.style.bottom = (bottom > -1 ? bottom + 'px' : '');
       tabbarEle.classList.add('show-tabbar');

src/components/tabs/test/advanced/app.module.ts

@@ -315,6 +315,11 @@ export class Tab2Page3 {
 
   constructor(public navCtrl: NavController) {}
 
+  ionViewCanLeave() {
+    console.log('Tab2Page3, ionViewCanLeave', false);
+    return false;
+  }
+
   ionViewWillEnter() {
     console.log('Tab2Page3, ionViewWillEnter');
   }

src/components/tabs/test/advanced/tab2page3.html

@@ -4,8 +4,9 @@
   <h2>Tab 2, Page 3</h2>
 
   <p>No Header.</p>
+  <p>This page can't be left</p>
 
-  <p><button ion-button (click)="navCtrl.pop()">Back to Tab 2, Page 2</button></p>
+  <p><button ion-button navPop>Back to Tab 2, Page 2</button></p>
   <div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div>
   <div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div><div f></div>