[Ajax] if callback function has parameters?

[ankur rathi]

    
function getInfo() {
createRequest();
var ss = document.getElementById("ss").value;
var url = "names?ss="+ss;
request.open("GET", url, true);
request.onreadystatechange = updatePage;
request.send(null);
}
 
function updatePage(temp) {
alert(temp);
if(request.readyState == 4) {
var names = request.responseText;
document.getElementById("output").innerHTML = names;
}
}

Here now, how to pass the value to callback function for 'temp' variable?
If I change this line 'request.onreadystatechange = updatePage;', browser throw 'type mismatch error'.

TIA.

[Venkatraman Kandaswamy]

you can make the variables that you want to pass as global variables.

[Muhammad Saifuddin]

Originally posted by rathi ji:

    
request.onreadystatechange = updatePage; 

if you do this:

http.onreadystatechange = updatePage(temp);

then you are assigning the returned value of updatePage function

You could try this:

http.onreadystatechange = updatePage(temp);

function updatePage(v) {
return something {

}
hope its help
[ November 24, 2006: Message edited by: Saif uddin ]

[Bear Bibeault]

Originally posted by Venkatraman Kandaswamy:
you can make the variables that you want to pass as global variables.

What a horrible suggestion!

[Bear Bibeault]

You cannot change what somebody else's code is going to pass to the callback function. You need to write your callback to adhere to the signature that the calling code will use.

In this case, the callback function is defined to accept the XMLHttpRequest instance. Normally, you could add your data as properties onto that object to "tag along" for the ride, but because IE6 implements it as an ActiveX object, you can't do this in this case.

Rather, use a closure:

  var someExtraData = 213;
  request.onreadystatechange = function(xhr) { updatePage(someExtraData); }
 

[ November 24, 2006: Message edited by: Bear Bibeault ]