desktopNotifications.js

// Created by Mike Hoffert ("Omega")
// CC-BY-SA

// Time in miliseconds between updates
var REFRESH_TIME = 2000;

// Get query arguments
var get_data = {};
var args = location.search.substr(1).split(/&/);
var version = '';

// Break up URL to find the get queries
for (var i = 0; i < args.length; i++)
{
    var tmp = args[i].split(/=/);
    if(tmp[0] != "")
    {
        get_data[decodeURIComponent(tmp[0])] = decodeURIComponent(tmp.slice(1).join("").replace("+", " "));
    }
}

// Check if there's a version query
if(get_data['version'])
{
    version = get_data['version'];
}

var serverList = {};
var firstLoop = true;

// If we don't already have permission to display desktop notifications, request it.
if (window.webkitNotifications && window.webkitNotifications.checkPermission() != 0)
{
    window.webkitNotifications.requestPermission();
}

/*
 * Check the JSON data for changes
 */
function timedRequest()
{
    // Get JSON of server list
    var request = new XMLHttpRequest();
    request.open('GET', 'showServersJson.php', true);
    request.send();

    // Function calls as soon as we receive the right data from the site
    request.onreadystatechange = function()
    {
        if (request.readyState == 4 && request.status == 200)
        {
            // Parse the JSON data for safety
            var jsonText = JSON.parse(request.responseText);

            var newServerList = {};

            // Loop through all json objects
            for(var i = 0; i < jsonText.length; i++)
            {
                // Check if version filter is active
                if(version == '' || jsonText[i].glestVersion == version)
                {
                    // Store data in an array keyed by the concatenation of the IP and port
                    var identifier = jsonText[i].ip + jsonText[i].externalServerPort;
                    newServerList[identifier] = { 'ip': jsonText[i].ip, 'port': jsonText[i].externalServerPort, 'title': jsonText[i].serverTitle, 'free': (jsonText[i].networkSlots - jsonText[i].connectedClients), 'version': jsonText[i].glestVersion };

                    // Only check for changes if NOT the first time
                    if(!firstLoop)
                    {
                        // Check if new server doesn't exist in old list
                        if( (newServerList[identifier].free > 0) && !serverList[identifier])
                        {
                            // Create notification
                            notification = window.webkitNotifications.createNotification('icon.png', 'Open server', 'Server "' + newServerList[identifier].title + '" has ' + newServerList[identifier].free + ' free slots available. Click to join now.');
                            notification.onclick = function() { window.location.assign('http://play.mg/?version=' + newServerList[identifier].version + '&mgg_host=' + newServerList[identifier].ip + '&mgg_port=' + newServerList[identifier].port); };
                            notification.show();
                        }
                    }
                    else
                    {
                        firstLoop = false;
                    }
                }
            }
            // Replace old list with new one
            serverList = newServerList;

            // Catch empty case
            if(jsonText.length == 0)
            {
                serverList = { };
            }
        }
        // Empty server list
        else if(request.readyState == 4 && request.status == 0)
        {
            serverList = { };
        }
    }
}

setInterval(timedRequest, REFRESH_TIME);