Not able to subscribe the PushManager

Question

I am nww to GAE and push API/service workers, I am trying to subscribe the pushManager but, pushManager getSubscription method handler returns the null reference

navigator.serviceWorker.ready.then(function(serviceWorkerRegistration)
 {      console.log('in side ready ' );
     // Do we already have a push message subscription?  
     serviceWorkerRegistration.pushManager.getSubscription()  
       .then(function(subscription) {  

         // Enable any UI which subscribes / unsubscribes from  
         // push messages.  
         var pushButton = document.querySelector('.js-push-button');  
         pushButton.disabled = false;

         if (!subscription) {  
           // We aren't subscribed to push, so set UI  
           // to allow the user to enable push        console.log('subscription error ' ); 
           return;  
         }  console.log('subscriptioned ' );
         // Keep your server in sync with the latest subscriptionId
         sendSubscriptionToServer(subscription);

         // Set your UI to show they have subscribed for  
         // push messages  
         pushButton.textContent = 'Disable Push Messages';  
         isPushEnabled = true;  
       })  
       .catch(function(err) {  
         console.warn('Error during getSubscription()', err);  
       });     });

In able code getSubscription() then returns subscription value as null, so that, control comes to if block and function is existing

if i am trying to call the

serviceWorkerRegistration.pushManager.subscribe() 

then I am getting the below error

registration failed - no sender id provided

Please find the working progress url below https://dtatable-date-filter.googleplex.com/home

Answer 1

Assuming this is in chrome you need to include a sender id in the manifest file.

You obtain such sender id by creating a project in google's developer console.

You can get a detailed set of steps in:

https://developers.google.com/web/updates/2015/03/push-notifications-on-the-open-web?hl=en

Read from section: "Make a Project on the Google Developer Console" onwards.

You can see an example of a manifest file with its own sender id here: https://johnme-gcm.appspot.com/manifest.json

Note the two relevant keys needed to make push work: "gcm_user_visible_only": true, "gcm_sender_id": "..." <- Create your own and replace ... with it.