Develop Reference

Refresh page after function has been called

Is there a way that I can run a function then call window.location.reload() to refresh the page? Currently when I do this the page is refreshing but the function isn't running.
function postComment() {
var name;
if (document.getElementById("yourName").value == "") {
name = "(Anonymous)";
} else {
name = document.getElementById("yourName").value;
}
var uri = "http://tgg.tcs.com/AP/Open/Service.svc/comment?name=" + name;
var xhr = new XMLHttpRequest();
xhr.open("POST", uri, true);
xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8")
xhr.onreadystatechange = function() {
if(http.readyState == 4 && http.status == 200) {
alert(xhr.responseText);
}
}
xhr.send(JSON.stringify(document.getElementById("comment").value));
}

You need to use a callback
function yourFunction(arg, callback) {
doSomeStuff(arg);
callback();
}
yourFunction('argument', window.location.reload);
If doSomeStuff function is async, you have to do
function yourFunction(arg, callback) {
doSomeStuff(arg, callback);
}
yourFunction('argument', window.location.reload);
also, if you refresh the page, you will refresh the scripts as well, so it depends on what does your function do, you may need a cookie if the data the function generates has to be persistant

Web Workers and JSON

I am sure there is something that I am missing from this code, I just can not figure out what it is.
Here is the main page:
<script>
function wwCallback(e) {
document.write(e.data);
}
function wwError(e) {
alert(e.data)
}
$(document).ready(function () {
var worker = new Worker("sync.js");
worker.onmessage = wwCallback;
worker.onerror = wwError;
worker.postMessage({
'cmd': 'downloadUser',
'url': 'server.php'
});
console.log("WW Started");
});
</script>
Server.php simply echoes a JSON string and I have verified that it is both valid and working using normal ajax requests.
Here is my web workers code:
function getData(url) {
var req = new XMLHttpRequest();
//expect json
req.open('GET', url);
req.send(null);
req.onreadystatechange = function () {
if (req.readyState == 4) {
if (req.status == 200) {
self.postMessage(req.responseText);
}
}
}
}
self.addEventListener('message', function (e) {
var data = e.data;
switch (data.cmd) {
case 'downloadUser':
getData(data.url);
}
self.close();
}, false);
Could anyone point me in the right direction?

Your problem is in your WebWorker XHR call. You've opened the request, then immediately sent it before you've set up the event handler to handle the response. You just need to move the req.send(null); call below the code that sets up the event handler.
Try this:
function getData(url) {
var req = new XMLHttpRequest();
//expect json
req.open('GET', url);
// req.send(null); // remove this line from here.
req.onreadystatechange = function () {
if (req.readyState == 4) {
if (req.status == 200) {
self.postMessage(req.responseText);
}
}
}
req.send(null); // make the request after your readystatechange
// handler is set up.
}
self.addEventListener('message', function (e) {
var data = e.data;
switch (data.cmd) {
case 'downloadUser':
getData(data.url);
}
self.close();
}, false);

ajax - javascript function to refresh a div

I'm trying to have a div refresh after a callback using ajax functions. Basically, I want /includes/view_game/achievements.inc.php to be reloaded in the div #achievements_tab. The callback (I didn't include it in codes below) works well and triggers the AchievementRefresh function found below (the opacity of the div changes to 0.5, but it remains like this and the refresh is not made).
Those two functions are used for another similar ajax refresh on my site that works well. So I tried to modify the code, but since it's for a slightly different purpose, maybe I have the wrong approach.
function AjaxPost(url, success_function) {
xmlHttp = GetXmlHttpObject();
if (xmlHttp == null) {
alert("Your browser doesn't support AJAX. You should upgrade it!")
return
}
xmlHttp.onreadystatechange = success_function;
xmlHttp.open("POST", url, true);
xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
}
This AjaxPost function is used in the other function below:
function AchievementRefresh() {
div('achievements_tab').style.opacity = 0.5;
div('highscore_pages').innerHTML = '<img src="'+site_url+'/images/loader.gif" />';
AjaxPost(site_url+"/includes/view_game/achievements.inc.php?", '',
function () {
div('achievements_tab').innerHTML = xmlHttp.responseText;
div('achievements_tab').style.opacity = 1;
}
)
}

Use load
$('#achievements_tab').load('/includes/view_game/achievements.inc.php');
See: http://api.jquery.com/load/
Edit
E.g.
function AchievementRefresh() {
$('#achievements_tab').css('opacity', 0.5);
$('#highscore_pages').html('<img src="'+site_url+'/images/loader.gif" />');
$('#achievements_tab').load('/includes/view_game/achievements.inc.php')
.success(function() {
$('#achievements_tab').css('opacity', 1);
});
}

Try this.
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4) {
if(xmlhttp.status == 200) {
div('achievements_tab').innerHTML = xmlHttp.responseText;
div('achievements_tab').style.opacity = 1;
}
}
};`
Name and id is example.
Also, some changes:
AjaxPost(site_url+"/includes/view_game/achievements.inc.php");
var params= 'name'+encodeURIComponent(name)+'&id='+encodeURIComponent(id)
Parameters shouldn't be in URL.
xmlhttp.send(params);

Problem of using ajax call at the same time

Now, I have a problem with the ajax call which is when the web page is loaded, in the onload event of body, I assign it to call the functions which are startCount() and updateTable() this two functions contain the code that use ajax call to get the data from DB on the server side. The problem is when the ajax return it will return only one call and another call does not response. Please help me what happen and how I can slove it.
This is the onload in the body
<body onLoad="setAjaxConnection();startCount();updateTable()">
I use the XMLHttpRequest with the normal javascript, I do not use jQuery....

Use javascript closures. This link may help
http://dev.fyicenter.com/Interview-Questions/AJAX/How_do_I_handle_concurrent_AJAX_requests_.html
function AJAXInteraction(url, callback) {
var req = init();
req.onreadystatechange = processRequest;
function init() {
if (window.XMLHttpRequest) {
return new XMLHttpRequest();
} else if (window.ActiveXObject) {
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
function processRequest () {
if (req.readyState == 4) {
if (req.status == 200) {
if (callback) callback(req.responseXML);
}
}
}
this.doGet = function() {
req.open("GET", url, true);
req.send(null);
}
this.doPost = function(body) {
req.open("POST", url, true);
req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
req.send(body);
}
}
function startCount() {
var ai = new AJAXInteraction("/path/to/count.php", function(){alert("After startCount");});
ai.doGet();
}
function updateTable() {
var ai = new AJAXInteraction("/path/to/update.php", function(){alert("After updateTable");});
ai.doGet();
}

Have the 'onSuccess' of one call initiate the next ajax call. So you would call startCount() and when that returns you fire off updateTable().

function setAjaxConnection(){
//call Ajax here
setAjaxConnectionResponce;
}
function setAjaxConnectionResponce(){
//on readystate==4
startCount();
}
function startCount(){
// code for count
updateTable();
}
function updateTable(){
// code for update
}
<body onLoad="setAjaxConnection();">

Ajax not working in firefox without alert

function processAjaxStateChangeForRowAdd() {
alert(0);
if (req.readyState == 4) { // Complete
if (req.status == 200) { // OK response
processForRowAdd(req.responseText);
} else {
alert("Problem: " + req.statusText);
}
}
}
This code is working fine for IE, Safari and Firefox, but if I remove the alert, then the code will not work in Firefox, though it still works in IE and Safari.
Can anybody give me suggestion why it not working in Firefox without alert?
EDIT: Code that adds a row:
if (window.XMLHttpRequest && browserVersion.indexOf("Microsoft") == -1 ) {
// code for Firefox, Chrome, Opera, Safari
req = new XMLHttpRequest("");
if (req) {
ajaxProcessed = false;
req.onreadystatechange = processAjaxStateChangeForRowAdd;
req.open("POST", url, true);
req.send();
// alert("1");
}
}

The alert is blocking. What this means is that your script is temporarily suspended (even if it's for a few milliseconds). During this time, your AJAX request completes and your req object is being set. You can add a delay (using setTimeout) to your callback to verify this.
I would suggest you post more of your script so that we can help you set up your callback properly. Alternatively, use a library such as jQuery to set up AJAX calls in a cross-browser manner easily.
EDIT: You need to either declare req as a global variable, or use an anonymous function. The following code demonstrates the first method (using a global variable):
var req;
if (window.XMLHttpRequest) {
req = new XMLHttpRequest();
if (req) {
req.onreadystatechange = processAjaxStateChangeForRowAdd;
req.open("POST", url, true);
req.send();
}
}
function processAjaxStateChangeForRowAdd() {
if (req.readyState == 4) { // Complete
if (req.status == 200) { // OK response
processForRowAdd(req.responseText);
} else {
alert("Problem: " + req.statusText);
}
}
}

function getHttp()
{
var xmlhttp;
try
{
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{
try
{
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e)
{
if(typeof XMLHttpRequest != 'undefiend')
{
xmlhttp = new XMLHttpRequest();
}
}
}
return xmlhttp;
}

can you try this:
if (request.readyState == 4) {
if (request.status == 200) {
var response = request.responseText;
} else
alert("status: " + request.status);
}

You should also check for the readyState , the following code might help
req.onreadystatechange=function()
{
if (req.readyState==4 && req.status==200)
{
processForRowAdd(req.responseText)
}
}
Read this for the different values of readyState