gistfile1.txt

var vapidPublicKey = new Uint8Array(#{Base64.urlsafe_decode64($vapid_public).bytes});

function checkNotifs(obj){
   if (!("Notification" in window)) {                                             //1
        console.error("This browser does not support desktop notification");
      }
      // Let's check whether notification permissions have already been granted
      else if (Notification.permission === "granted") {                           //2
        console.log("Permission to receive notifications has been granted");
        getKeys();
      }
      // Otherwise, we need to ask the user for permission
      else if (Notification.permission !== 'denied') {                            //3
        Notification.requestPermission(function (permission) {                    
              // If the user accepts, let's create a notification
          if (permission === "granted") {                                         //4
            console.log("Permission to receive notifications has been granted");
            getKeys();                                                       
          } 
        });
     }
}

  function getKeys(){
    navigator.serviceWorker.register('/serviceworker.js', {scope: './'})          //5
      .then(function(registration) {
        return registration.pushManager.getSubscription()
          .then(function(subscription) {
            if (subscription) {
              return subscription;
            }
            return registration.pushManager.subscribe({                           //6
              userVisibleOnly: true,
              applicationServerKey: vapidPublicKey
            });
          });
      }).then(function(subscription) {
        sendKeys(subscription.toJSON())                                           //7
      });
  }

  function sendKeys(subscription){
    $.post('/sendkeys, {
        subscription: subscription,
        message: 'You clicked a button!'
      });
  }