Ionic 3: Back Button Hardware Event Handler Can't Determine Overlay Views

Question

I have an ionic 3 application and I modified the functionality of the hardware back button. It works on pages but it cannot determine whether overlay views like modals and alert dialog boxes are present or not.

Here is my code

    this.platform.registerBackButtonAction(() => { 
      let nav = app._appRoot._getActivePortal() || app.getActiveNav();
      let activeView = nav.getActive().instance;

      if (activeView != null) {
        if (nav.canGoBack()) {
            if (activeView instanceof MultiRegistrationOne || activeView instanceof MultiRegistrationTwo || activeView instanceof MultiRegistrationThree) {
                // do something
            } else {
               nav.pop();
            }
        } else if (activeView.isOverlay) {
          activeView.dismiss();
        } else {
          let alert = this.alertCtrl.create({
            title: 'Ionic App',
            message: 'Do you want to close the app?',
            buttons: [{
              text: 'Cancel',
              role: 'cancel',
              handler: () => {
                console.log('Application exit prevented!');
              }
            },
            {
              text: 'Close',
              handler: () => {
                this.platform.exitApp();
              }
            }]
          });
          alert.present();
        }
      }
    });

I hope someone can help me with this. Thank you in advance 😊

Answer 1

I solved it using MD. Riyas' answer here: Solution