Javascript Ajax Function Problem

[jjacquay712]

I have a javascript function that is supposed to return a number from a php script, but when i call the function, its value is undefined. here is the function:

(function to get xmlhttp variable not shown)

function latestid() {
xmlHttp.onreadystatechange=function(){
if( xmlHttp.readyState == 4 ) {
return xmlHttp.responseText;
}

}
xmlHttp.open("get",'ajax/latestid.php',true);
xmlHttp.send(null);
}

is there any problems you see in my code? or suggestions on why it isnt working? thanks, John Jacquay

 

[feherke]

Hi

No problem in that short code.

What you get if you request the ajax/latestid.php "manually" by typing it in your browser's location bar ?

If that is Ok, the next step would be to check the HTTP headers with an adequate tool :
[ul]
[li]Browser:
[ul]
[li]FireFox:
[ul]
[li]Live HTTP Headers[/li]
[li]FireBug[/li]
[li]Web Developer[/li]
[/ul]
[/li]
[li]Lynx[/li]
[li]Links[/li]
[li]W3M[/li]
[li]Explorer:
[ul]
[li]ieHTTPHeaders[/li]
[li]IEWatch[/li]
[/ul]
[/li]
[/ul]
[/li]
[li]tool:
[ul]
[li][tt]netcat[/tt][/li]
[li]PuTTY[/li]
[li][tt]telnet[/tt][/li]
[li][tt]Wget[/tt][/li]
[/ul]
[/li]
[/ul]

Feherke.

http://rootshell.be/~feherke/

 

[tsuji]

[1] Put all your functional script operating on the supposed return responseText into a function say, operate. As an example like this.
[tt]
function operate(s) { //s supposedly the responseText
//alert(s); //for instance
document.getElementById("xyz").innerHTML=s; //for instance
}
[/tt]
[2] Modify the latestid() to contain a boolean parameter. Initially, passing false say.
[tt]
function latestid_2(brecur) {
if (!brecur) {
xmlHttp.onreadystatechange=function(){
if( xmlHttp.readyState == 4 ) {
operate(xmlHttp.responseText);
}
}
xmlHttp.open("get",'ajax/latestid.php',true);
xmlHttp.send(null);
setTimeout("latestid_2(true)",200);
} else if (xmlHttp.readyState!=4) {
setTimeout("latestid_2(true)",200);
}
}
[/tt]
[3] Replace the latestid() by taking into consideration of [1], ie, moving all the functional lines depending on responseText to the function operate(s), and put instead at the place latestid_2(false). Like this.
[tt]
//document.getElementById("xyz").innerHTML=latestid();
//replaced by
latestid_2(false);
[/tt]
And the functionality should be more of less well-prepared and ready to go.