ajax : function(typ,url,callback) {
if(window.XMLHttpRequest) {
var xml = new XMLHttpRequest();
}
if(window.ActiveXObject) {
var xml = new ActiveXObject("Microsoft.XMLHTTP");
}
xml.onreadystatechange = function(callback) {
if(xml.readyState == 4 && xml.status == 200) {
callback();
}
}
xml.open(typ,url,true);
xml.send();
}
}
//Function being called
window.onload = function() {
JS.ajax("GET","/server/chkEmail.php?email=email#email.com",function() {
alert(xml.responseText);
});
}
It throws the error saying:
Uncaught TypeError: callback is not a functionxml.onreadystatechange #
global.js:30
Any ideas?
I fixed it by passing the data variable through the onreadystatechange function and calling it in the callback function.
ajax : function(typ,url,callback) {
if(window.XMLHttpRequest) {
var xml = new XMLHttpRequest();
}
if(window.ActiveXObject) {
var xml = new ActiveXObject("Microsoft.XMLHTTP");
}
xml.onreadystatechange = function(data) {
if(xml.readyState == 4 && xml.status == 200) {
var data = xml.responseText;
callback(data);
}
};
xml.open(typ,url,true);
xml.send();
}
}
window.onload = function() {
JS.ajax("GET","/server/chkEmail.php? email=jonwcode#gmail.com",function(data){
alert(data);
});
}
Try like this:
xml.onreadystatechange = function() {
if (xml.readyState == 4 && xml.status == 200) {
callback();
}
};
Notice that the onreadystatechange function doesn't take any parameters whereas in your code you have passed it a parameter with the name callback which will override the callback variable from the outer scope.
UPDATE:
It looks like you have improperly scoped the xml variable and it isn't available in your AJAX callback. I strongly recommend you reading more about javascript variables scope. Here's how you could make the xml variable visible:
var xml = null;
if (window.XMLHttpRequest) {
xml = new XMLHttpRequest();
} else if (window.ActiveXObject) {
xml = new ActiveXObject("Microsoft.XMLHTTP");
}
if (xml == null) {
alert('Sorry, your browser doesn\'t seem to support AJAX - please upgrade to a modern browser');
} else {
xml.onreadystatechange = function() {
if(xml.readyState == 4 && xml.status == 200) {
var data = xml.responseText;
callback(data);
}
};
xml.open(typ,url,true);
xml.send();
}
Related
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?
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 $error_reporting was set to "maximum" in configuration.php.
Still though - there has to be a better way.
I have a simple ajax script which returns a json dump from the server:
var request = false;
try {
request = new XMLHttpRequest();
} catch (trymicrosoft) {
try {
request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (othermicrosoft) {
try {
request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (failed) {
request = false;
}
}
}
function getIslandName() {
var islandGroup = document.getElementById("id_island_group").value;
var url = ".../find_island?island_group=" + escape(islandGroup);
request.open("GET", url, true);
request.onreadystatechange = updatePage;
request.send(null);
}
function updatePage() {
if (request.readyState == 4)
if (request.status == 200)
var data = JSON.decode(request.responseText);
update(data);
//document.getElementById("ajax_response").innerHTML = request.responseText;
else if (request.status == 404)
alert("Request URL does not exist");
else
alert("Error: status code is " + request.status);
}
function update(data) {
for (var key in data) {
alert(data[key]);
}
}
The problem seems to be in the updatePage() function. If I uncomment this line:
//document.getElementById("ajax_response").innerHTML = request.responseText;
the responseText json dump is displayed as expected. e.g.:
["Foo Island", "Bar Island", "Darwin Island"]
Also if I construct a fresh data array within the updatePage() function like so:
function updatePage() {
var string = "Something something ajax";
if (request.readyState == 4)
if (request.status == 200)
var data=new Array();
data[0]="Foo Island";
data[1]="Bar Island";
data[2]="Darwin Island";
update(data);
}
The update() function works as expected and gives the expected alert output.
Any suggestions as to what I'm doing wrong will be much appreciated.
I found a reference for an XMLHttpRequest
final req = new XMLHttpRequest();
req.open('GET', '${Sections.home}/data/$name', false);
req.send();
_htmlBody = req.responseText;
Full Source
But this is for async = false, is there a working example of async = true?
There is an example at https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/samples/belay/bcap/bcap_client.dart
void privateInvoke(String ser, String method, String data,
SuccessI ski, FailureI fki) {
if (urlRegex.hasMatch(ser)) {
var req = new XMLHttpRequest();
req.open(method, ser, true);
req.on.readyStateChange.add(void _(evt) {
if (req.readyState == 4) {
if (req.status == 200) {
ski(req.responseText);
} else {
fki(new BcapError(req.status, req.statusText));
}
}
});
req.send(data);
return;
} else {
super.privateInvoke(ser, method, data, ski, fki);
}
}
also another asynchronous example in https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/client/samples/total/src/ServerChart.dart
XMLHttpRequest request = new XMLHttpRequest();
request.on.readyStateChange.add((Event event) {
if (request.readyState == XMLHttpRequest.DONE && request.status == 200) {
callback("data:image/png;base64,${StringUtils.base64Encode(request.responseText)}");
}
});
...
request.open("POST", url, true, null, null);
request.setRequestHeader("Content-type", "text/plain");
request.overrideMimeType("text/plain; charset=x-user-defined");
print("Chart request: ${data}");
request.send(data);
See the following function I have written
The code is to receive a url and send data to that page in post/get method.The function returns responseText from the target page
function $send(url,data,method)
{
if(window.XMLHttpRequest)
var connect = new XMLHttpRequest();
else
var connect = newActiveXObject("Microsoft.XMLHTTP");
if(connect)
{
method = method.toUpperCase();
if(method == 'GET')
{
url += '?'+data;
connect.open(method,url,true);
connect.send();
}
else
{
connect.setRequestHeader("Content-type","application/x-www-form-urlencoded");
connect.open(method,url,true);
connect.send(data);
}
connect.onreadystatechange = function()
{
alert(connect.readyState);
if(connect.readyState==4 &&connect.status == 200)
{
return connect.responseText ;
}
}
return "FALSE";
}
else
{
alert("$sendData() is not supported by your browser\n\nTRY ANOTHER BROWSER!!!");
return "FALSE";
}
}
As readstate is initially 0 and changes eventually,my function always return FALSE.Is there any way to return the responseText