Checking Ajax ready state

[Anubh Jain]

Hi all,

I need some help in javascripting.

I am using a xmlhttprequest object wherein i expect a readystate of 4 from the server.
I need to put a check wherein if I dont receive a readsystate of 4 in certain time(say 1 sec), i want to display a error message.

Please show some pointers to this.

Thanks in advance.

[Bear Bibeault]

Where's your code, and what specific problems are you having with it?

[Anubh Jain]

Thanks bear for pointing out about title.

I have a code of something like:

DSMakeConnection.Connect=function ()
{ 
	var xmlhttp = new XMLHttpRequest(); 
	
	var cURL = //some URL
	alert("Conecting to URL:"+cURL);
	
	var connectionStatus = null;
	if(xmlhttp)
	{
		xmlhttp.onreadystatechange=function()
		{
				
			if (xmlhttp.readyState==4)
			{
				alert("In xmlhttp.readyState==4");	
				if(xmlhttp.status==200)
				{
				    //some functionality to set connectionstatus
                                }
				else
				{
					
					//404 error
				}
			}
			
		}
	}
	else
	{
		alert("Connect: xmlhttp is null");
	}
	
	xmlhttp.open("GET",cURL,false); 
	xmlhttp.send() ;
	
	return (connectionStatus);
} 

No in case my server is down, or connection in disconnected, I am recieving any response. So how do I put a timeout so that I can return an error message.

I hope it makes picture a little clear.

[Bear Bibeault]

Any reason that you are doing this "by hand" as opposed to with a library like jQuery that already has that built in?

[Anubh Jain]

Please provide some pointers for that.

[Bear Bibeault]

http://api.jquery.com/category/ajax/

If you want to go it alone, you'll need to set a timeout and cancel the request if it expires. Don't forget to cancel the timer if it doesn't time out.

[Anubh Jain]

DSMakeConnection.Connect=function ()
{
	$.ajax(
	{
		type:'GET',
		url:/*some url*/,
		timeout:15000,
		success:function(xmlDoc)
		{
			//some functionality 
		},

		error:function(XMLHttpRequest, textStatus, errorThrown)
		{
			
			
		}
	});
	
	return connectionStatus ;
}

Now in this code where do i put the timeout so that when the response is not received in particular time, error is displayed.

[Bear Bibeault]

Search this page for the word "timeout" and it should give you the clues you need to progress.