NativeScript handling back button event

Question

I am trying to handle the hardware back button in a NativeScript app. I am using NativeScript version 2.3.0 with Angular.

Here is what I have in main.ts

Answer 1

As far as I know, NativeScript has a built-in support for this but it's not documented at all. Using onBackPressed callback, you can handle back button behaviour for View components (e.g. Frame, Page, BottomNavigation).

Example:

function pageLoaded(args) {
  var page = args.object;
  page.onBackPressed = function () {
    console.log("Returning true will block back button default behaviour.");
    return true;
  };
  page.bindingContext = homeViewModel;
}

exports.pageLoaded = pageLoaded;

What's tricky here is to find out which view handles back button press in your app. In my case, I used a TabView that contained pages but the TabView itself handled the event instead of current page.