send web push notification for all users - node.js

Question

up to now I have created my push notification service for my angular app using service worker, app manifest and fire-base.
I'm getting the server key and sender_id. I' m registering my service worker and subscribe to the push_messenger.
also I'm using google local server extension to host my server.
main.ts
Notification.requestPermission(function (status) {
console.log('Notification permission status:', status);
});
if ('serviceWorker' in navigator) {
navigator.serviceWorker.register('./service-worker.js', { scope: './' }).then(function (registration) {
// Registration was successful
console.log('ServiceWorker registration successful with scope: ', registration.scope);
console.log('registration: ', (registration));
navigator.serviceWorker.ready.then(reg => {
reg.pushManager.getSubscription().then(sub => {
if (sub == undefined) {
console.log('sub : ' + 'undefined');
navigator.serviceWorker.getRegistration().then((reg) => {
reg.pushManager.subscribe({
userVisibleOnly: true
}).then(sub => {
console.log('sub : ' + JSON.stringify(sub));
localStorage.setItem("sub", JSON.stringify(sub));
}, err => {
console.log('registration error occured: ' + err);
})
}, err => {
console.log('registration error occured: ' + err);
})
} else {
console.log('sub : ' + sub);
// subs = sub;
localStorage.setItem("sub", JSON.stringify(sub));
}
}, err => {
console.log('registration error occured: ' + err);
});
})
}).catch(function (err) {
// registration failed :(
console.log('ServiceWorker registration failed: ', err);
});
}
service-worker.js
self.addEventListener('notificationclose', function(e) {
var notification = e.notification;
var primaryKey = notification.data.primaryKey;
console.log('Closed notification: ' + primaryKey);
});
self.addEventListener('notificationclick', function(e) {
var notification = e.notification;
var primaryKey = notification.data.primaryKey;
var action = e.action;
if (action === 'close') {
notification.close();
} else {
clients.openWindow('samples/page' + primaryKey + '.html');
notification.close();
}
// TODO - close all notifications when one is clicked
});
self.addEventListener('push', function(e) {
var body;
if (e.data) {
body = e.data.text();
} else {
body = 'Push message no payload';
}
var options = {
body: body,
icon: 'images/notification-flat.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: "I don't want any of this",
icon: 'images/xmark.png'},
]
};
e.waitUntil(
self.registration.showNotification('Push Notification', options)
);
});
node server
var webPush = require('web-push');
var pushSubscription = {<subscription object>}
};
var payload = 'Sup Dude!';
var options = {
gcmAPIKey: *<server key>*,
TTL: 60,
};
webPush.sendNotification(
pushSubscription,
payload,
options
);
in the above main.ts I was able to get the subscription object when the app was initialized. and able to send the push notification at that moment. but when I open this same server IP from chrome I'm getting a different subscription object. also sometime I'm getting different subscription object using chrome.
the questions is How can I send push notifications for all users, since the subscription object is differ from time to time and browser to browser.
(cannot store all the data to a database which will be excessive amount of storage)

Answer 1

I think you should use FCM for this purpose. Where you can create a group and send notification to all of them. But even for creating group you would require deviceId for each device.
You can store all these id's with you in backend and send FCM web push to all.
https://firebase.google.com/docs/cloud-messaging/js/client
You can go through FCM documentation achieve this.

Answer 2

This is official firebase cloud-messaging documention very usefull...!
also checkout below link,
firebase cloud-messaging google
firebase cloud-messaging staring (subscribe this channel)
This is my working code for push notification token registration at client-side, may be work for you
<script>
messaging.requestPermission()
.then(function() {
console.log('Notification permission granted.');
// TODO(developer): Retrieve an Instance ID token for use with FCM.
messaging.getToken()
.then(function(currentToken) {
if (currentToken) {
console.log(currentToken);
settingTokenToServer(currentToken);
} else {
// Show permission request.
console.log('No Instance ID token available. Request permission to generate one.');
setTokenSentToServer(false);
refreshToken();
}
})
.catch(function(err) {
console.log('An error occurred while retrieving token............................... ', err);
});
})
.catch(function(err) {
console.log('Unable to get permission to notify.', err);
});
messaging.onTokenRefresh(function() {
messaging.getToken()
.then(function(refreshedToken) {
console.log('Token refreshed.');
// Indicate that the new Instance ID token has not yet been sent to the
// app server.
setTokenSentToServer(false);
// Send Instance ID token to app server.
sendTokenToServer(refreshedToken);
// ...
})
.catch(function(err) {
console.log('Unable to retrieve refreshed token ', err);
showToken('Unable to retrieve refreshed token ', err);
});
});
function settingTokenToServer(subscription_id) {
if (!isTokenSentToServer()) {
//setting token to FCM server
var ref = firebase.database().ref("notes/token");
ref.push({subscription_id}).then(function() {
console.log("Token saved Successfully..!");
}).catch(function(error) {
alert("Token not saved..." + error);
});
setTokenSentToServer(true);
} else {
console.log('Token already sent to server so won\'t send it again unless it changes');
}
}
function isTokenSentToServer() {
return window.localStorage.getItem('sentToServer') == 1;
}
function setTokenSentToServer(sent) {
window.localStorage.setItem('sentToServer', sent ? 1 : 0);
}
</script>