Webkit Notifications on Multiple Tabs - html

Question

I am using WebKit Notifications for my app. Say if I am using this code:
var n = window.webkitNotifications.createNotification(
'icon.png',
'New Comment',
'Praveen commented on your post!'
);
n.onclick = function(x) { window.focus(); this.cancel(); };
n.show();
PS 1: The first five lines are actually a single line. Just for readability I have posted this way.
PS 2: For the full code, please see this: Unable to show Desktop Notifications using Google Chrome.
My question is, what if I have more than one tab opened?
Say if this is gonna get fired when a new comment appears on my app. What if I have more than one tab open? Will this generate many notifications? Say, I have 10 - 15 tabs open and I get two notifications fired. How many notifications will be generated, 20 - 30?
If that is the case, how to prevent generation of a single notification multiple times for each opened tab?

Answer 1

You just need to specify "tag" option for notification. Notifications with the same value in tag only shows once even if many tabs are opened.
For example:
var notification = new Notification('Hey!', {
body : 'So nice to hear from you',
tag : 'greeting-notify',
icon : 'https://mysite.com/my_funny_icon.png'
});

Answer 2

A detailed explanation of Tagging notifications so only the last one appears is available
on the MDN docs site
An excerpt of the code [just in case the docs go down]
The HTML
<button>Notify me!</button>
The JS
window.addEventListener('load', function () {
// At first, let's check if we have permission for notification
// If not, let's ask for it
if (Notification && Notification.permission !== "granted") {
Notification.requestPermission(function (status) {
if (Notification.permission !== status) {
Notification.permission = status;
}
});
}
var button = document.getElementsByTagName('button')[0];
button.addEventListener('click', function () {
// If the user agreed to get notified
// Let's try to send ten notifications
if (Notification && Notification.permission === "granted") {
for (var i = 0; i < 10; i++) {
// Thanks to the tag, we should only see the "Hi! 9" notification
var n = new Notification("Hi! " + i, {tag: 'soManyNotification'});
}
}
// If the user hasn't told if he wants to be notified or not
// Note: because of Chrome, we are not sure the permission property
// is set, therefore it's unsafe to check for the "default" value.
else if (Notification && Notification.permission !== "denied") {
Notification.requestPermission(function (status) {
if (Notification.permission !== status) {
Notification.permission = status;
}
// If the user said okay
if (status === "granted") {
for (var i = 0; i < 10; i++) {
// Thanks to the tag, we should only see the "Hi! 9" notification
var n = new Notification("Hi! " + i, {tag: 'soManyNotification'});
}
}
// Otherwise, we can fallback to a regular modal alert
else {
alert("Hi!");
}
});
}
// If the user refuses to get notified
else {
// We can fallback to a regular modal alert
alert("Hi!");
}
});
});