Adapt ajax for crossdomain - ajax

Is it possible adapt this code for crossdomain and how
function makeRequest(url) {
var http_request = false;
if (window.XMLHttpRequest) { // Mozilla, Safari,...
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {
http_request.overrideMimeType('text/xml');
}
} else if (window.ActiveXObject) { // IE
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!http_request) {
alert('Cannot create an XMLHTTP instance');
return false;
}
http_request.onreadystatechange = function() { alertContents(http_request); };
http_request.open('GET', url, true);
http_request.send(null);
}
function alertContents(http_request) {
if (http_request.readyState == 4) {
if (http_request.status == 200) {
receiveData(http_request.responseText);
} else {
alert("Îòâåò ñåðâåðà ïîëó÷åí, íî åñòü îøèáêà");
}
}
}

The same origin policy prevents JavaScript reading data from different origins under normal circumstances.
You can work around with:
A proxy for the data on the page's origin
JSONP
CORS (limited browser support, but possibly good enough for prime time now)

Related

How can I send a synchronous ajax request to my server in onunload function

I need to send a ajax request to my server before web page close, my send code is below.
SendByAajx = function(msg) {
var response;
var xmlHttpReg;
if(window.XMLHttpRequest){
xmlHttpReg = new XMLHttpRequest();
} else if(window.ActiveXObject) {
xmlHttpReg = new ActiveXObject("Microsoft.XMLHTTP");
} else {
throw new Error("Unsupported borwser");
}
if(xmlHttpReg != null) {
xmlHttpReg.open("get", "https://127.0.0.1:57688/test"+'?'+msg, false);
xmlHttpReg.send(null);
if(xmlHttpReg.readyState==4){
if(xmlHttpReg.status == 200) {
var data = JSON.parse(xmlHttpReg.responseText);
if(typeof(data.errorcode) == "number" &&
data.errorcode != 0) {
throw("response error:" + data.errorcode);
}
response = data.result;
} else {
throw new Error("Error");
}
}
}
return response;
}
When I call this function in a button onclick event, it works.
function GetOnClick() {
try{
var result = SendByAajx (“data”);
} catch (e) {
//alert(errorInfo);
}
SetButtonDisabled(false);
}
But when I call this function when the page is unloaded, it doesn't work.
<body onload="javascript:OnLoad();" onunload="javascript:OnUnLoad()">
function OnUnLoad() {
try{
var result = SendByAajx(“data”);
} catch (e) {
//alert(errorInfo);
}
}
When I debug the application, the JS execution stops after this line:
xmlHttpReg.send(null);
It didn’t go to the next line:
if(xmlHttpReg.readyState==4)
The “data” is also not sent to the server.
What is wrong with my program, can ajax be called in an onunload function? What should I do to make it work?

Joomla 1.5 AJAX XMLHttpRequest Code Not Working in Joomla 2.5

Can someone tell me why this will not work in Joomla 2.5 but does in 1.5?
The error I'm receiving is - Uncaught TypeError: Cannot read property 'childNodes' of null ajax.php:33
If I enter in the url: index.php?option=com_mmg&controller=ajax&task=listModels&make_id=3
It outputs the ajxGetModels function like it's suppose to.
I know Joomla 2.5 Ajax Calls got changed or something like that but, I can't find a solution online to convert what I have below to the 2.5 version way of doing so.
Any help or direction would be very useful. Thank you.
function ajxGetModels(reload)
{
if (reload) {
var use_make = 'sel_make_id';
} else {
var use_make = 'make_id';
}
var make_id = document.getElementById(use_make).value;
var xhr = createXHR();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4) {
if (xhr.status == 200) {
var model=document.getElementById("model_id");
try //Internet Explorer
{
xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async="false";
xmlDoc.loadXML(xhr.responseText);
}
catch(e)
{
try //Firefox, Mozilla, Opera, etc.
{
parser=new DOMParser();
xmlDoc=parser.parseFromString(xhr.responseText,"text/xml");
}
catch(e) {alert(e.message)}
}
var options =xmlDoc.getElementsByTagName("options").item(0);
model.innerHTML='';
for (i=0; i < options.childNodes.length; i++){
var newoption=document.createElement("option");
var myoption=options.childNodes[i];
var newtext=document.createTextNode(myoption.childNodes[0].nodeValue);
newoption.setAttribute("value",myoption.getAttributeNode("id").value)
newoption.appendChild(newtext);
model.appendChild(newoption);
}
document.getElementById('model_id').disabled=false;
document.getElementById('year_id').innerHTML='';
document.getElementById('year_id').disabled=true;
if (reload) {
var preVal = document.getElementById('sel_model_id').value;
setMmgVal('model_id',preVal);
ajxGetYears(true);
}
} else {
alert('Error code ' + xhr.status);
}
}
}
xhr.open("GET","index.php?option=com_mmg&controller=ajax&task=listModels&make_id="+make_id,true);
xhr.send(null);
}
function createXHR() {
var xhr = null;
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else if (window.ActiveXObject) {
try {
xhr = new ActiveXObject('Microsoft.XMLHTTP');
} catch (e) {}
}
return xhr;
}
It was not working because $error_reporting was set to "maximum" in configuration.php.
Still though - there has to be a better way.

Facebook App/Page Tab with xmlHttpRequest doesn't work in Firefox

I have e really big problem with firefox and facebook.
I mad an application on my webserver which uses xmlHttpRequest. I added this application to a facebook tab on a test facebook page. It works with IE, Chrome, Safari but not with firefox.
The request just keeps loading until timeout.
The JS functions i'm using:
function createXmlHttpRequest() {
try {
if (typeof ActiveXObject != 'undefined') {
return new ActiveXObject('Microsoft.XMLHTTP');
} else if (window["XMLHttpRequest"]) {
return new XMLHttpRequest();
}
} catch (e) {
changeStatus(e);
}
return null;
};
function downloadUrl(url, callback) {
var status = -1;
var request = createXmlHttpRequest();
if (!request) {
return false;
}
request.onreadystatechange = function() {
if (request.readyState == 4) {
try {
status = request.status;
} catch (e) {
}
if (status == 200) {
callback(request.responseXML, request.status);
request.onreadystatechange = function() {};
}
}
}
request.open('GET', url, f);
try {
request.send(null);
} catch (e) {
changeStatus(e);
}
};
function xmlParse(str) {
if (typeof ActiveXObject != 'undefined' && typeof GetObject != 'undefined') {
var doc = new ActiveXObject('Microsoft.XMLDOM');
doc.loadXML(str);
return doc;
}
if (typeof DOMParser != 'undefined') {
return (new DOMParser()).parseFromString(str, 'text/xml');
}
return createElement('div', null);
}
function downloadScript(url) {
var script = document.createElement('script');
script.src = url;
document.body.appendChild(script);
}
i call it through downloadUrl()
The Headers from the requested files:
header('Access-Control: allow <*>');
header("Access-Control-Allow-Origin: *");
header('Access-Control-Allow-Methods: GET');
header('Access-Control-Allow-Headers: X-PINGOTHER');
header("Content-type: text/xml");
i really tried everything, but it won't work in firefox...
what i've noticed: by observing firebug while loading this app in the facebook tab i could see that facebook is not requesting the adress given in the source, but other ones like: https://0-317.channel.facebook.com/pull?channel=p_1495135952&seq=389&partition=7&clientid=420773d2&cb=682&idle=0&state=active
i think it's surely firefox cross domain policy... but how can i solve this problem?
Anyone had the same problems ?
I thank you in advance.
Greetings
ok, found the problem.
Facebook is using UTF-8, but my page wasn't. So the stopped at the umlauts.
So it wasn't the Request at all.

problem with AJAX request

i hava created the ajax XMLHttpRequest request for getting the data dyanmically ,
here is the code
var XMLHttpReq;
function createXMLHttpRequest() {
if (window.XMLHttpRequest) {
XMLHttpReq = new XMLHttpRequest();
} else {
if (window.ActiveXObject) {
try {
if(XMLHttpReq==null)
XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e) {
try {
if(XMLHttpReq==null)
XMLHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {
}
}
}
}
}
this is the method which sends the request
function personList(person) {
createXMLHttpRequest();
var url="query?option=person&userName="+person.innerHTML;
XMLHttpReq.open("GET", url, true);
XMLHttpReq.onreadystatechange =personListResponse;
XMLHttpReq.send(null);
}
function personListResponse() {
if (XMLHttpReq.readyState == 4) {
if (XMLHttpReq.status == 200) {
var xml=XMLHttpReq.responseXML;
}
}
}
the request is sent to the servlet only for the first time,when i try for the second the request is not sent ,instead am getting the previous response what i got earlier
I suppose it's cache.
Try adding this before the request:
XMLHttpReq.setRequestHeader("Cache-Control", "no-store, no-cache, must-revalidate");
XMLHttpReq.setRequestHeader("Cache-Control", "post-check=0, pre-check=0");
XMLHttpReq.setRequestHeader("Pragma", "no-cache");
If it doesn't work, try adding an additional parameter to your url, making it unique and therefore, not caching.
var url="query?option=person&userName="+person.innerHTML + "&d=" + new Date().getTime()
I really don't like this solution, but it helps you to know if the problem is related to cache.

msxml XMLHTTP for large json object works very slow on IE8 and quite good on Firefox - why?

I am creating an XMLHTTP object in Firefox and IE8 and i transfer a very large amount of data (json). In Firefox it renders it in 5 seconds, in IE8 it takes 30 seconds.
Is there any way to make IE8 XMLHTTP works faster?
Here is my code for creating the XHR object:
function createRequestObject2()
{
var http_request = false;
if(window.XMLHttpRequest)
{ //: Mozilla, Safari,...
http_request = new XMLHttpRequest();
if(http_request.overrideMimeType)
{
//: set type accordingly to anticipated content type
//http_request.overrideMimeType('text/xml');
}
}
else if(window.ActiveXObject)
{ //: IE
try
{
http_request = new ActiveXObject("Msxml2.XMLHTTP.3.0");
}
catch (e)
{
try
{
http_request = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) { }
}
}
if(!http_request)
{
alert('Cannot create XMLHTTP instance');
return false;
}
return http_request;
}
Here is how i use the XHR:
http = createRequestObject2();
http.open('GET', encodeURI(action), true);
http.onreadystatechange = results;
http.send(null);
inwork = true;
viewLoading();
//: search results handling
function results()
{
/*console.log("do_search.results[ " +
'Results return ' + http.readyState
+ " ]"
);*/
if(http.readyState != 4)
return;
inwork = false;
if(http.status != 200)
{
//setStatusLine(httpapplicant.statusText);
return;
}
//: evaluate
var data = eval('(' + http.responseText + ')');
//: add data to the table
applicant_list = new dogtable(data, table1_options, $$('dog_results'));
hideLoading();
} //function results

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