NativeScript handling back button event
I'm using NativeScript with Angular as well and this seems to work quite nicely for me:
import { RouterExtensions } from "nativescript-angular";
import * as application from "tns-core-modules/application";
import { AndroidApplication, AndroidActivityBackPressedEventData } from "tns-core-modules/application";
export class HomeComponent implements OnInit {
constructor(private router: Router) {}
ngOnInit() {
if (application.android) {
application.android.on(AndroidApplication.activityBackPressedEvent, (data: AndroidActivityBackPressedEventData) => {
if (this.router.isActive("/articles", false)) {
data.cancel = true; // prevents default back button behavior
this.logout();
}
});
}
}
}
Note that hooking into the backPressedEvent is a global thingy so you'll need to check the page you're on and act accordingly, per the example above.
import { Component, OnInit } from "@angular/core";
import * as Toast from 'nativescript-toast';
import { Router } from "@angular/router";
import * as application from 'application';
@Component({
moduleId: module.id,
selector: 'app-main',
templateUrl: './main.component.html',
styleUrls: ['./main.component.css']
})
export class MainComponent {
tries: number = 0;
constructor(
private router: Router
) {
if (application.android) {
application.android.on(application.AndroidApplication.activityBackPressedEvent, (args: any) => {
if (this.router.url == '/main') {
args.cancel = (this.tries++ > 0) ? false : true;
if (args.cancel) Toast.makeText("Press again to exit", "long").show();
setTimeout(() => {
this.tries = 0;
}, 2000);
}
});
}
}
}