Remove HTML5 notification permissions

Question

You can prompt a user to allow or deny desktop notifications from the browser by running:

Notification.requestPermission(callback);

But is it possible to remove that permission by code? We want our users to have the option to toggle notifications. Can this be achieved by JavaScript or do we need to save that option elsewhere?

Answer 1

Looking at the documentation on Notification at MDN and WHATWG, there does not seem to be a way to request revocation of permission. However, you could emulate your own version of the permission using localStorage to support that missing functionality. Say you have a checkbox that toggles notifications.

<input type="checkbox" onChange="toggleNotificationPermission(this);" />

You can store your remembered permissions under the notification-permission key in local storage, and update the permission state similar to:

function toggleNotificationPermission(input) {
    if (Notification.permission === 'granted') {
        localStorage.setItem('notification-permission', input.checked ? 'granted' : 'denied');
    } else if (Notification.permission === 'denied') {
        localStorage.setItem('notification-permission', 'denied');
        input.checked = false;
    } else if (Notification.permission === 'default') {
        Notification.requestPermission(function(choice) {
            if (choice === 'granted') {
                localStorage.setItem('notification-permission', input.checked ? 'granted' : 'denied');
            } else {
                localStorage.setItem('notification-permission', 'denied');
                input.checked = false;
            }
        });
    }
}

You could retrieve the permission as:

function getNotificationPermission() {
    if (Notification.permission === 'granted') {
        return localStorage.getItem('notification-permission');
    } else {
        return Notification.permission;
    }
}

When you want to display a notification, check your permission:

if (getNotificationPermission() === 'granted') {
    new Notification(/*...*/);
}