How can we detect timeout on an AJAX XmlHttpRequest call in the browser

Question

Looking on the web, but documentation is hard to come by. We all know the basic AJAX call using the browser's built-in XMLHttpRequest object (assume a modern browser here):

var xmlHttp = new XMLHttpRequest();  // Assumes native object

xmlHttp.open("GET", "http://www.example.com", false);

xmlHttp.send("");

var statusCode = xmlHttp.status;
// Process it, and I'd love to know if the request timed out

So, is there a way that I can detect that the AJAX call timed out by inspecting the XMLHttpRequest object in the browser? Would I be advised to do something like window.setTimeout(function() { xmlHttp.abort() }, 30000);?

Answer 1

Hii,

In order to handle a timeout:

var xmlHttp = new XMLHttpRequest();
xmlHttp.open("GET", "http://www.example.com", true);

xmlHttp.onreadystatechange=function(){
   if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
      clearTimeout(xmlHttpTimeout); 
      alert(xmlHttp.responseText);
   }
}
// Now that we're ready to handle the response, we can make the request
xmlHttp.send("");
// Timeout to abort in 5 seconds
var xmlHttpTimeout=setTimeout(ajaxTimeout,5000);
function ajaxTimeout(){
   xmlHttp.abort();
   alert("Request timed out");
}

In IE8, You can add a timeout event handler to the XMLHttpRequest object.

var xmlHttp = new XMLHttpRequest();
xmlHttp.ontimeout = function(){
  alert("request timed out");
}

Hope this works!! 

Thank You!!