main.js

Notification.requestPermission(function(status) {
    console.log('Notification permission status:', status);
});

function displayNotification() {
  if (Notification.permission == 'granted') {
    navigator.serviceWorker.getRegistration().then(function(reg) {
      var options = {
        body: 'Here is a notification body!',
        icon: 'images/example.png',
        vibrate: [100, 50, 100],
        data: {
          dateOfArrival: Date.now(),
          primaryKey: 1
        },
        actions: [
          {action: 'explore', title: 'Explore this new world',
            icon: 'images/checkmark.png'},
          {action: 'close', title: 'Close notification',
            icon: 'images/xmark.png'},
        ]
      };
      reg.showNotification('Hello world!', options);
    });
  }
}

if ('Notification' in window && navigator.serviceWorker) {
  // Display the UI to let the user toggle notifications
}

if (Notification.permission === "granted") {
  /* do our magic */
} else if (Notification.permission === "blocked") {
 /* the user has previously denied push. Can't reprompt. */
} else {
  /* show a prompt to the user */
}

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('sw.js').then(function(reg) {
    console.log('Service Worker Registered!', reg);

    reg.pushManager.getSubscription().then(function(sub) {
      if (sub === null) {
        // Update UI to ask user to register for Push
        console.log('Not subscribed to push service!');
      } else {
        // We have a subscription, update the database
        console.log('Subscription object: ', sub);
      }
    });
  })
   .catch(function(err) {
    console.log('Service Worker registration failed: ', err);
  });
}