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AJAX request sometimes out of order

I'm having trouble with POST and GET request. On my server side right up until the moment before I send I have what I expect but then on my client side I get things out of order. For example these two should be in the reverse order I have here:
Sending from server{"grid":["","","","","","","","",""],"winner":""}
Received at server: {"grid":["X","","","","","","","",""],"winner":""}
function sendData(json) {
$.ajax({
type: "POST",
url: "/ttt",
data: json,
dataType: "json",
success: receiveData()
});
}
function receiveData() {
var response = $.ajax({
type: "GET",
url: "/ttt",
dataType: "json",
success: function(){
grid = response.responseJSON;
console.log("Receved at client: " + JSON.stringify(grid));
}
});
console.log("Also after receiving " + JSON.stringify(grid));
}
gives me:
Also after receiving {"grid":["X","","","","","","","",""],"winner":""}
Receved at client: {"grid":["X","O","","","","","","",""],"winner":""}
I think this may two different problems. One for getting things out of order and another for why my grid doesnt reflect the changes after my success clause function in my GET request.

You're making a common mistake. You need to use a function reference without the parens here for receiveData. Change this:
function sendData(json) {
$.ajax({
type: "POST",
url: "/ttt",
data: json,
dataType: "json",
success: receiveData()
});
}
to this:
function sendData(json) {
$.ajax({
type: "POST",
url: "/ttt",
data: json,
dataType: "json",
success: receiveData // no parens here
});
}
When you include the parens, it calls the function IMMEDIATELY and puts the return value from the function as the success handler and thus you see them run out of order. You want to pass a function reference to it can be called later. A function reference is the function's name without the parens.
It also appears like you have another mistake in receiveData(). You are using the wrong thing for the response. The response is not returns from $.ajax(). The response is passed to the success handler.
I don't know exactly what your response is supposed to look like, but change this:
function receiveData() {
var response = $.ajax({
type: "GET",
url: "/ttt",
dataType: "json",
success: function(){
grid = response.responseJSON;
console.log("Receved at client: " + JSON.stringify(grid));
}
});
console.log("Also after receiving " + JSON.stringify(grid));
}
to something like this:
function receiveData() {
$.ajax({
type: "GET",
url: "/ttt",
dataType: "json",
success: function(response){
grid = response.responseJSON;
console.log("Received at client: " + JSON.stringify(grid));
console.log("Also after receiving " + JSON.stringify(grid));
}
});
}
And, because your ajax calls are asynchronous, you also had this statement console.log("Also after receiving " + JSON.stringify(grid)); in the wrong place. If you want to see the results of the grid after you've modified it, then you have to put that inside the success handler.
Summary of Fixes
Change success: receiveData() to success: receiveData.
Use response as it is passed to the success handler.
Put console.log() to see final results inside the success handler.
It appears that you may not fully understand how ajax calls are asynchronous and what that really means for your programming. I'd suggest doing some searching and reading on that topic. Learning that now will save you a lot of agony as you develop.

updated UI not showing before sync ajax call

I Have a 2 JavaScript functions what call one after another. like following.
updateUI(event);
syncCall();
function updateUI(event) {
formSubmitBtn = $(event.target).find('[type=submit]:not(".disabled")');
formSubmitBtn.attr('disabled', 'disabled');
var loadingText = I18n.t('Submitting');
formSubmitBtn.val(loadingText).text(loadingText);
}
function syncCall(){
$.ajax({
async: false,
dataType: 'json',
type: 'GET',
url: '/calls/synccall',
success: function (json) {
userIsSignedIn = json.is_signed_in;
}
});
}
I am updating a UI element before sync ajax call. but UI changes are not showing. When I try to debug the code it works fine.

I can imagine your code is doing something like
var userIsSignedIn;
updateUI(event);
syncCall();
nextThing(userIsSignedIn);
anotherThing();
moreThings();
With a simple change to syncCall - called asyncCall to be not confusing
function asyncCall(cb){
$.ajax({
dataType: 'json',
type: 'GET',
url: '/calls/synccall',
success: function (json) {
cb(json.is_signed_in);
}
});
}
your code re-written:
updateUI(event);
asyncCall(function(userIsSignedIn) {
nextThing(userIsSignedIn);
anotherThing();
moreThings();
});
Note the lack of var userIsSignedIn; required
Really a small change for improved end user experience
a second alternative is to wrap all the code you presented in a function tagged async
async function doThings() {
updateUI(event);
let userIsSignedIn = await ajaxCall(); // see below
nextThing(userIsSignedIn);
anotherThing();
moreThings();
}
and return a Promise from ajaxCall (what was syncCall)
function ajaxCall(){
return $.ajax({
dataType: 'json',
type: 'GET',
url: '/calls/synccall'
}).then(json => json.is_signed_in);
}
Run this through a transpiler (like babel) to produce code that should work on Internet Exploder and similarly "backward" browsers
Summary: In the end you have two choices
Use async:false and have rubbish user experience
embrace asynchrony and write code that befits the 21st century

Call this function beforeSend like as follows
function syncCall(){
$.ajax({
async: false,
dataType: 'json',
type: 'GET',
url: '/calls/synccall',
beforeSend:function(){
updateUI(event);// Call here
}
success: function (json) {
userIsSignedIn = json.is_signed_in;
}
});
}
If above not work try following
updateUI(event);
function updateUI(event) {
formSubmitBtn = $(event.target).find('[type=submit]:not(".disabled")');
formSubmitBtn.attr('disabled', 'disabled');
var loadingText = I18n.t('Submitting');
formSubmitBtn.val(loadingText).text(loadingText);
syncCall();// Try calling here
}
function syncCall(){
$.ajax({
async: false,
dataType: 'json',
type: 'GET',
url: '/calls/synccall',
success: function (json) {
userIsSignedIn = json.is_signed_in;
}
});
}

AJAX trigger remote script then check for success-response

I've been searching my brains out but I can't seem to wrap my head around the little help I find.
I'm running a database that is being fed by data from another DB. The csv transport is handled by a third party server providing executable "flows" which compile and deliver the data.
I have a php script to handle the request (can't be done directly via Javascript because of the missing 'Access-Control-Allow-Origin' header). But this runs nicely. I can trigger the flow.
This is not the problem though.
What I want to do: trigger the flow #onClick of a button with something like this:
function trigger_func(flowID) {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID,
dataType: 'json',
success: function(result) {
var jsonResult = jQuery.parseJSON(result);
console.log(jsonResult.runID);
}
});
}
With the flowID and the resulting runID I want to check back like every second or so.
function check_status(flowID, runID) {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID+"&action=status&runId="+runID,
dataType: 'json',
success: function(result){...}
});
}
This will return the status / progress of the flow.
It will start for a few seconds with status==null, then go on to status=='running' and finally status=='success'.
I have gotten check_status() to run for i.e. 15 times with a setTimeout in a for loop within the success-function of trigger_func() and it works fine too.
But I cannot for the life of me figure out how I would link this stuff together to have it checking until status is 'success' and then stop checking, update page content and so on...
I have also fiddled with something like
trigger_func(id).done(function(result){
console.log(result);
});
This works too but still I can't think my way further to the checking every second until 'success'. I guess it comes down to getting the variable 'status' back into my loop so I can break it.
Maybe someone knows of a comprehensible example somewhere online...

You could do this:
function periodically_check_status_until_success(flowID, runID) {
setTimeout(function() {
$.ajax({
url: './ajaxPHP_handler.php',
data: { flowid: flowID, action: status, runId: runID },
dataType: 'json',
success: function(result){
if (result != 'success') {
periodically_check_status_until_success(flowID, runID);
}
}
});
}, 5000); // Five seconds
}
Note: You can use an object for the data option, rather than concatenate the string yourself.

So just keep calling it
var flowID, runID;
function trigger_func(flowID) {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID,
dataType: 'json',
success: function(result) {
var jsonResult = jQuery.parseJSON(result);
runID= jsonResult.runID;
check_status();
}
});
}
function check_status() {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID+"&action=status&runId="+runID,
dataType: 'json',
success: function(result){
if (result is not what you want) {
setTimeout(check_status,1000);
}
}
});
}

ajax are async so you have to manage by this via some 3rd party variable
Like Init with value 0
var _status = 0
than change it on your first call set it 1
function trigger_func(flowID) {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID,
dataType: 'json',
success: function(result) {
var jsonResult = jQuery.parseJSON(result);
console.log(jsonResult.runID);
check_status(flowID, runID);
}
});
}
function check_status(flowID, runID) {
$.ajax({
url: './ajaxPHP_handler.php',
data: "flowid="+flowID+"&action=status&runId="+runID,
dataType: 'json',
success: function(result){
//at end status=='success'.
if(status=='success'){
// end part
}else{// running
check_status(flowID, runID);
}
// clear timeout will stop that time interval after success
}
});
}

Ajax redirect on error

I'm calling php file through ajax call and if it returns nothing i want to redirect user to another page (It's for error reports, if it doesn't return anything it means that user logged in). Tried to add error section but it doesn't work. Any suggestions will help. Thanks! Btw, I have small jQuery function at the top of the ajax function, why it breaks my whole ajax call?
ajax.js
function loginAjax() {
//$("#email_errors").empty(); //This function doesnt work and kills whole ajax call. Here is loginAjax function call line - <button type = "submit" id = "push_button" onclick = "loginAjax(); return false">PushMe</button>
$.ajax({
url: "Classes/call_methods_login.php",
type: "POST",
dataType: "json",
data: {
login_email: $("#login_email").val(),
login_password: $("#login_password").val(),
},
success: function(data) {
$("#login_error").html(data.login_message);
}
});
}

$.ajax({
url: "Classes/call_methods_login.php",
type: "POST",
dataType: "json",
data: {
login_email: $("#login_email").val(),
login_password: $("#login_password").val(),
},
success: function(data) {
$("#login_error").html(data.login_message);
},
error: function(){
window.location.replace("http://stackoverflow.com");
}
});
}

To redirect using javascript all you need to do is override the location.href attribute.
function loginAjax() {
$.ajax({
url: "Classes/call_methods_login.php",
type: "POST",
dataType: "json",
data: {
login_email: $("#login_email").val(),
login_password: $("#login_password").val(),
},
// the success method is deprecated in favor of done.
done: function(data) {
$("#login_error").html(data.login_message);
},
fail: function(data) {
location.href="path/to/error/page";
}
});
}

$.ajax wait for completion without hanging the UI

Let's say for example, I have the following javascript function that returns a boolean:
function CallWebServiceToUpdateSessionUser(target, user)
{
var dataText = { "jsonUser": JSON.stringify(user) };
$.ajax({
type: "POST",
url: target,
data: JSON.stringify(dataText),
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (response)
{
return true;
},
failure: function (msg)
{
return false;
}
});
}
and the target function on the server that is being called could take up to... 15 seconds to respond.
How do I guarantee that this function will not exit until after the server call has been completed? Or, how can I guarantee that who ever is calling this function will get a true/false and not an undefined?
NOTE:
I've seen people use async: false but that hangs the UI which I do not want.

See http://api.jquery.com/jQuery.ajax/. You need to do an AJAX request with async: true to your parameters. You will then need to edit your code so the code that executes after a successful request is inside the successful block.