Full implementation of webkitNotifications API for Firefox 22+.

webkitNotifications-shim.js

// ==UserScript==
// @name        webkitNotifications shim for Firefox 22+
// @namespace   https://github.com/Rob--w/
// @author      Rob Wu <gwnRob@gmail.com>
// @description Enable desktop notifications on Firefox 22+ for websites which use the webkitNotification API.
// @include     *
// @version     1.0.2
// @grant       none
// ==/UserScript==

/**
 * (c) 2013 Rob Wu <gwnRob@gmail.com>
 * License: WTFPL
 *
 * This shim fully implements the legacy webkitNotifications API
 * Usable as a library or user script.
 *
 * References:
 * - http://www.chromium.org/developers/design-documents/desktop-notifications/api-specification
 * - http://notifications.spec.whatwg.org/
 * - chromium/src/third_party/WebKit/Source/modules/notifications/Notification.h
 * - chromium/src/third_party/WebKit/Source/modules/notifications/Notification.idl
 */

(function(global) {
    'use strict';
    if (global.webkitNotifications || typeof Notification == 'undefined') return;

    global.webkitNotifications = {
        createNotification: createNotification,
        PERMISSION_ALLOWED: 0,
        PERMISSION_NOT_ALLOWED: 1,
        PERMISSION_DENIED: 2,
        checkPermission: function() { return permission; },
        requestPermission: requestPermission
    };
    var permission = 1; // Default permission = "Not allowed"
    function createNotification(iconURL, title, text) {
        var notificationOptions = {};
        if (text) notificationOptions.body = text;
        if (iconURL) notificationOptions.icon = iconURL;
        notificationOptions.title = title || '';

        var notification;
        // List of events which we want to expose
        var eventNames = [
            'onshow',
            'onerror',
            'onclose',
            'onclick'
        ];
        // Object which holds the DOM0 event listener until the notification is shown.
        var eventTarget = {};
        // An implementation of the webkitNotification interface
        var webkitNotification = {
            show: function show() {
                if (notification) return;
                notification = new Notification(title, notificationOptions);
                // Call delayed addEventListener, removeEventListener, ...
                var o;
                while( (o = replayQueue.shift()) ) {
                    notification[o.methodName].apply(notification, o.arguments);
                }
                // Synchronize DOM0 events
                eventNames.forEach(function(eventName) {
                    notification[eventName] = eventTarget[eventName];
                });
                eventTarget = notification;
            },
            cancel: function cancel() {
                if (notification) notification.close();
            },
            // Not in spec, but present in Chrome. Included for consistency.
            close: function close() {
                if (notification) notification.close();
            }
        };
        // Implement EventTarget on webkitNotification
        var replayQueue = [];
        [
            'addEventListener',
            'removeEventListener',
            'dispatchEvent'
        ].forEach(function(methodName) {
            webkitNotification[methodName] = function() {
                // Call method directly on the notification object, if available.
                if (notification) return notification[methodName].apply(notification, arguments);
                // Notification not yet visible, queue the call for later use.
                replayQueue.push({methodName: methodName, arguments: arguments});
            };
        });
        // Implement DOM0 event binding.
        eventNames.forEach(function(eventName) {
            defProp(eventName, {
                get: function() { return eventTarget[eventName] || null; },
                set: function(f) { eventTarget[eventName] = typeof f == 'function' ? f : null; }
            });
        });
        // Alias ondisplay <> onshow
        defProp('ondisplay', Object.getOwnPropertyDescriptor(webkitNotification, 'onshow'));

        // dir and tag setters. Only relevant before the show() method has been called.
        ['dir', 'tag'].forEach(function(propertyName) {
            defProp(propertyName, {
                get: function() { return notificationOptions[propertyName] || ''; },
                set: function(value) { notificationOptions[propertyName] = value; }
            });
        });
        // Alias replaceId <> tag
        defProp('replaceid', Object.getOwnPropertyDescriptor(webkitNotification, 'tag'));


        // Shorthand for defining properties on webkitNotification
        function defProp(propertyName, descriptor) {
            descriptor.enumerable = true;
            Object.defineProperty(webkitNotification, propertyName, descriptor);
        }
        return webkitNotification;
    }
    function requestPermission(callback) {
        Notification.requestPermission(function(p) {
            permission = p == 'granted' ? 0 : p == 'denied' ? 2 : /*'default*/ 1;
            if (callback) {
                callback();
            }
        });
    }
})(typeof unsafeWindow == 'undefined' ? this : unsafeWindow);

This seems to have an issue: requestPermission can take a callback function for when the user closes the request dialog. I fixed it as:

function requestPermission(cb) {
    Notification.requestPermission(function(p) {
        permission = p == 'granted' ? 0 : p == 'denied' ? 2 : /*'default*/ 1;
        if(cb)
            cb();
    });
}

This is working for me for google calendar, but not gmail. Every time I load gmail, it offers to enable notifications, and I click enable. The first time I got a popup to confirm the permissions, but no more. gmail never shows me any notifications, and I don't get any errors in the error console.

I got this working in my end. The only problem is that when you refresh the browser, it seems to discard the permission that you have chosen. Any thoughts on this one?

BTW, awesome job in this one!

@Eraiph fixed in my fork https://gist.github.com/adambom/7755821