Simple Long Polling Example with JavaScript and jQuery by Tian Davis (@tiandavis) from Techoctave.com (http://techoctave.com/c7/posts/60-simple-long-polling-example-with-javascript-and-jquery)
// The setInterval Technique (Not Recommended - Creates Queues of Requests ∴ Can Be Slow)
setInterval(function(){
$.ajax({ url: "server", success: function(data){
//Update your dashboard gauge
salesGauge.setValue(data.value);
}, dataType: "json"});
}, 30000);
// The setTimeout Technique (Not Recommended - No Queues But New AJAX Request Each Time ∴ Slow)
(function poll(){
setTimeout(function(){
$.ajax({ url: "server", success: function(data){
//Update your dashboard gauge
salesGauge.setValue(data.value);
//Setup the next poll recursively
poll();
}, dataType: "json"});
}, 30000);
})();
// Long Polling (Recommened Technique - Creates An Open Connection To Server ∴ Fast)
(function poll(){
$.ajax({ url: "server", success: function(data){
//Update your dashboard gauge
salesGauge.setValue(data.value);
}, dataType: "json", complete: poll, timeout: 30000 });
})();