XMLHttpRequest status 4 but responseText is empty - php

Question

I am trying to write a google ads like javaScript plugin. I can not use jQuery ajax as it should be working fine for all sites.
Here is my JavaScript code.
var ajaxRequest; // The variable that makes Ajax possible!
try{
// Opera 8.0+, Firefox, Safari
ajaxRequest = new XMLHttpRequest();
} catch (e){
// Internet Explorer Browsers
try{
ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try{
ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e){
// Something went wrong
alert("Your browser broke!");
return false;
}
}
}
// Create a function that will receive data sent from the server
ajaxRequest.onreadystatechange = function(){
if(ajaxRequest.readyState == 4){
alert( ajaxRequest.responseText);
console.log('xhr',ajaxRequest)
} else {
//alert(ajaxRequest.readyState);
//alert(ajaxRequest.responseText);
}
}
var project_path = "http://www.domainname.com/"; //for stackoverflow, using right path in live code.
var req_url = project_path + "ads/verifypublisher/";
ajaxRequest.open("GET", req_url, true);
ajaxRequest.send(null);
And here is how my PHP file looks like,
echo("<b>hi:</b> ");
exit();
Yes, thats all i have there. Still responseText is empty. What am i missing here?

Answer 1

alert(req_url) should show wrong url "http://www.domainname.comads/verifypublisher/"

Answer 2

It's better to make sure the status code is 200 before doing anything with the response. Then you can spot problems earlier.

Answer 3

try this in my test it work in most of browser
var responseText=function(e,doing){
if (e.readyState== 4) {
if(doing)doing(e);
return(e.responseText);
};
if (e.readyState == 200) {
if(doing)doing(e);
return(e.responseText);
};
return false;
};
function loadXMLPostDocf(url,method,posData,uploadProgress,uploadComplete,uploadFailed,uploadCanceled,statechange,CallBackOnSend) {
var arrSignatures = ["MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0","MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP","Microsoft.XMLHTTP"];
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest && checkVersion()) {
pos = new XMLHttpRequest();
pos.open(method, url, true);
//pos.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
if(statechange!=''){pos.onreadystatechange = statechange;};
try{
if(uploadProgress!='')if(pos.upload){
pos.upload.addEventListener("progress", uploadProgress, true);
}else{
pos.addEventListener("progress", uploadProgress, true);
}
if(uploadComplete!='')pos.addEventListener("load", uploadComplete, false);
if(uploadFailed!='')pos.addEventListener("error", uploadFailed, false);
if(uploadCanceled!='')pos.addEventListener("abort", uploadCanceled, false);
}catch(e){
}
pos.send(posData);
if(CallBackOnSend)CallBackOnSend(pos);
//console.log(pos.abort());
// branch for IE/Windows ActiveX version
} else if (window.ActiveXObject) {
for (var i=0; i < arrSignatures.length; i++) {
try {
pos = new ActiveXObject(arrSignatures[i]);
} catch (oError) {
//ignore
};
};
if (pos) {
pos.open(method, url, false);
//pos.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
if(!statechange){pos.onreadystatechange = statechange;};
if(!uploadComplete){pos.onreadystatechange = uploadComplete;};
// if(uploadProgress!='')pos.upload.addEventListener("progress", uploadProgress, true);
//if(uploadComplete!='')pos.addEventListener("load", uploadComplete, false);
//if(uploadFailed!='')pos.addEventListener("error", uploadFailed, false);
//if(uploadCanceled!='')pos.addEventListener("abort", uploadCanceled, false);
pos.send(posData);
if(CallBackOnSend)CallBackOnSend(pos);
};
};
return(pos);
};
sample:
var complete=function(e){
var Body=responseText(e.target);
console.log(Body);
};
var uploadProgress=function(evt){
};
var uploadComplete=function(evt){
if(evt.target.status==200 || evt.target.status==304){
var Body=responseText(evt.target);
console.log(Body);
}else{
return false;
};
};
var uploadFailed=function(evt){
};
var uploadCanceled=function(evt){
};
var CallBackOnSend=function(evt){
};
loadXMLPostDocf("http://domain.com/index.php","GET",null,uploadProgress,uploadComplete,uploadFailed,uploadCanceled,complete,CallBackOnSend);

Answer 4

My problem similar to this was solved by checking my html code. I was having an onclick handler in my form submit button to a method. like this : onclick="sendFalconRequestWithHeaders()". This method in turn calls ajax just like yours, and does what I want. But not as expected, my browser was returning nothing.
Learned From someone's hardwork, I have returned false in this handler, and solved.
Let me mention that before arriving to this post, I have spent a whole 3-day weekend and a half day in office writing code implementing CORS filters, jetty config, other jersey and embedded jetty related stuff - just to fix this., revolving all my understanding around cross domain ajax requests and standards stuff. It was ridiculous how simple mistakes in javascript make you dumb.
Now I have to clean my code to submit git patch cleanly. Thanks to that someone.