Back button mystery in ionic conference app

tutorials
1

Hi all,

I’ve been learning ionic2 by going over the ionic conference app code. I am wondering why the back button does not show up in cases where you might expect.

For example the login page pushes a view on login:

if (form.valid) {
  this.userData.login(this.login.username);
  this.navCtrl.push(TabsPage);
}

I added some code to the tabs page to expose the NavController and App:

tabs.ts
 ionViewDidLoad() {
      console.log("Tab page canGoBack = ", this.navCtrl.canGoBack());
      // Returns the current stack of views in this nav controller.
      var viewArray = this.navCtrl.getViews();
      viewArray.forEach( function( view, i) {
      console.log("View index ",i,":",view.component)
 });
 console.log("Root Nav:", this.appCtrl.getRootNav());
}

So after you login and get to the tabs page, Here is the console output

Tab page canGoBack =  true
tabs.ts:39 View index  0 : function LoginPage(navCtrl, userData) {
    this.navCtrl = navCtrl;
    this.userData = userData;
    this.login = {};
    this.submitted = false;
}
tabs.ts:39 View index  1 : function TabsPage(navParams, navCtrl, appCtrl) {
    this.navCtrl = navCtrl;
    this.appCtrl = appCtrl;
    // set the root pages for each tab
    this.tab1Root = __WEBPACK_IMPORT…

So with the view stack like this I’m wondering why there’s no back button on the Tabs page in this case…

Thanks

2

Hmm I think I got it… the navbar belongs to the Tabs child view

canGoBack is false in the Schedule page