Tuesday, October 04, 2005

I'd like to share some really basic Javascript code that handles asynchronous XMLHTTP functionality in a bit more of a generic way than you can accomplish by hand coding each request. This is REALLY simple stuff, but I found it to be useful. It's not like the fullblown "AJAX frameworks", and it isn't intended to be. It's just a starting poing for doing basic work with the XMLHTTP object.

You can see the code here.

Here's the simple usage of the functions:

var xmlRequest = "SOME REQUEST TO POST";
saxf_sendAsync("http://tempuri.org/", xmlRequest, ReceiveSingleValue);

function ReceiveSingleValue(ResponseText, ResponseStatus)
{
 alert(ResponseText);
}

And here's a situation where you need to wait for two requests to return before doing anything:

var xmlRequest = "SOME REQUEST TO POST";
saxf_sendAsync("http://tempuri.org/page1", xmlRequest, ReceiveFirstValue);
saxf_sendAsync("http://tempuri.org/page2", xmlRequest, ReceiveSecondValue);

var FirstReturned = false;
function ReceiveFirstValue(ResponseText, ResponseStatus)
{
 if (SecondReturned)
  EverythingBack();

 FirstReturned = true;
}

var SecondReturned = false;
function ReceiveSecondValue(ResponseText, ResponseStatus)
{
 if (FirstReturned)
  EverythingBack();

 SecondReturned = true;
}

function EverythingBack()
{
 alert("We got both back");
}