Ionic Push Notifications - Use data after clicking notification

Question

I am trying to use Ionic push notifications. This is my current app.component.ts:

import { Component, ViewChild } from '@angular/core';
import { Nav, Platform } from 'ionic-angular';
import { StatusBar, Splashscreen } from 'ionic-native';
import {
  Push,
  PushToken
} from '@ionic/cloud-angular';

import { Page1 } from '../pages/page1/page1';
import { Page2 } from '../pages/page2/page2';


@Component({
  templateUrl: 'app.html'
})
export class MyApp {
  @ViewChild(Nav) nav: Nav;

  rootPage: any = Page1;

  pages: Array<{title: string, component: any}>;

  constructor(
    public platform: Platform,
    public push: Push
  ) {
    this.setupPushNotifications();
    this.initializeApp();

    // used for an example of ngFor and navigation
    this.pages = [
      { title: 'Page One', component: Page1 },
      { title: 'Page Two', component: Page2 }
    ];

  }

  initializeApp() {
    this.platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      StatusBar.styleDefault();
      Splashscreen.hide();
    });
  }

  openPage(page) {
    // Reset the content nav to have just this page
    // we wouldn't want the back button to show in this scenario
    this.nav.setRoot(page.component);
  }

  setupPushNotifications() {

    this.push.register().then((t: PushToken) => {
      return this.push.saveToken(t);
    }).then((t: PushToken) => {
      console.log('Token saved:', t.token);
    });

    this.push.rx.notification()
      .subscribe((msg) => {

        console.log(msg);

        alert(msg.title + ': ' + msg.text);
      });

  }

}

I am then using the following Node.js app to send push messages:

var request = require('request');

function sendMessageToUser(deviceId, message) {
  request({
    url: 'https://fcm.googleapis.com/fcm/send',
    method: 'POST',
    headers: {
      'Content-Type' :' application/json',
      'Authorization': 'key=AI....'
    },
    body: JSON.stringify(
      {
        "to" : deviceId,
        "notification": {
          "title": "Push Notification",
          "body": message,
          "sound": ""
        },
        "data": {
          "test": "test 1"
        }
      }
    )
  }, function(error, response, body) {
    if (error) {
      console.error(error, response, body);
    }
    else if (response.statusCode >= 400) {
      console.error('HTTP Error: '+response.statusCode+' - '+response.statusMessage+'\n'+body);
    }
    else {
      console.log('Done!')
    }
  });
}

sendMessageToUser(
  "eu....",
  'Test'
);

If the app is open and I send a push notification, the console.log() and the alert() execute OK. However when the app is in the background or the phone is locked, I get a notification as expected, but then when I click on this the app opens without executing either the console.log() or the alert() function.

Could someone please tell me how I can achieve this?

I have tried sending push notifications from Ionic.io's cloud system instead, and it works fine when using that so perhaps I am missing an option in my node app?

Thanks for any help.