如何获得Ajax请求的响应？

Question

I tried this code :

var xmlHttp = new XMLHttpRequest();

function activecomm(comm_id,a_link_id)
{
    var postComm = "id="+encodeURIComponent(comm_id);
    var url = 'comments_mgr_proccesser.php'; 
    xmlHttp.open("POST", url, true);
    xmlHttp.onreadystatechange = handleInfo(a_link_id);
    xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    xmlHttp.setRequestHeader("Content-length", postComm.length);
    xmlHttp.setRequestHeader("Connection", "close");
    xmlHttp.send(postComm);
}

function handleInfo(a_link_id)
{
    if(xmlHttp.readyState == 1)
    {
        document.getElementById("commactiveresult").innerHTML = 'loading ..';
    }
    else if(xmlHttp.readyState == 4)
    {
        var response = xmlHttp.responseText;
        document.getElementById("commactiveresult").innerHTML = response;
    }
}

When readyState == 1 the contents of the commactiveresult element is updated, but when readyState == 4 nothing is shown in the same element.

Does anyone know what the problem is please?

Answer 1

You're calling the handleInfo function instead of assigning a ready state handler. Try

xmlHttp.onreadystatechange = function (){
    handleInfo(a_link_id);
};