I have a form, on submit of that I am making an ajax request which is sometimes taking time to get the request, so what I am trying to do is whenever user refresh or clicks back button of the browser after form submitting i want to abort that ajax call
What I am doing is
$("#formId").submit(function(event) {
event.preventDefault();
var xhr = $.ajax({
url : "Drilldown",
method : "GET",
success : function(data) {
// here doing ,my stuff
},
complete : function() {
$('.loader').hide();
$('.overlay').hide();
}
});
window.onbeforeunload = function() {
return "some message"; // here when user clicks on leave then want to abort like `xhr.abort`
};
});
whenever the user clicks on leave I want to abort my ajax request
How can I do that?
**I specifically want to do that when ever form submit and once form is submitted,i want to abort that function also onbeforeunload **
You can directly xhr.abort() in "onbeforeunload" event handler method:
// Define xhr variable outside so all functions can have access to it
var xhr = null;
$("#formId").submit(function(event) {
event.preventDefault();
xhr = $.ajax({
url: "Drilldown",
method: "GET",
success: function(data) {
// here doing ,my stuff
},
complete: function() {
$('.loader').hide();
$('.overlay').hide();
}
});
});
window.onbeforeunload = onUnload;
function onUnload() {
if(xhr) xhr.abort();
return "some message";
};
call below method to abort ajax call
xhr.abort()
I have a local page that pulls data from a database and sends out a message. So I'm trying to have this page executed using javascript on "success" of another function. The problem is everything I've tried doesn't seem to execute that page, while the only success I've had on executing that page is using a window pop up, which is not desired.
This is the pop up code (undesired):
function sendMsg(){
var wnd = window.open("http://localhost/url");
if(wnd){
setTimeout(function () { wnd.close();}, 4000);
}
}
sendMsg();
And these are the codes I've tried but didn't execute the url:
$.get("http://localhost/url")
And this one which is from another answer here on SO.
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
var response = xmlhttp.responseText; returned value
}
}
xmlhttp.open("GET","http://localhost/url",true);
xmlhttp.send();
How can I have this URL executed without opening it on the browser in any way?
Just to be clear, I know the other two codes didn't work because I would have received a message.
if you really need a return data/page from get
you should do something like this.
$.get( "url", function( data ) {
console.log(data); // return data/page
alert( "Done load." );
});
# use ajax
$.ajax({
url: "url",
type: "GET",
success : function( data ){
console.log(data); // return data/page
alert("Done LOad");
}
});
anything else can refer : https://api.jquery.com/jquery.get/
I believe jQuery's load() method may be useful for this. For example, have a div in your HTML and just set it to hidden in the CSS.
jQuery load() Method
HTML:
<div id='myHiddenPage'></div>
CSS:
#myHiddenPage {
display: none;
}
jQUERY:
$(funtion() {
$('#myHiddenPage').load('www.myurl.com');
});
This is my ajax function
function repeatedCall() {
$.ajax({
url: '/getUrl',
complete: function(data) {
if (data.statusText != "error") {
//my actions
}
}
})
}
setInterval(repeatedCall, 5000); //To make repeated ajax calls
function updateData_function{
//I want to abort all previous ajax calls and make a new ajax call since it will update the data
}
I can use clearInterval but the pending calls are not getting aborted and hence it is not updating properly.
How can i make repeated calls and at the same time abort all the requests if it enters my updateData_function.
This updateData_function will have new values so i need to make fresh ajax request.
How can i do this? Please help!! Thanks a lot in advance!!
Using setInterval to make repetead calls is not a good practice. Assume that your previous request is not completed, then there is no point in making the same ajax call. Also, as you may know, there are possibility that the response from the previous ajax call can come after the recent ajax response. So it is always better to abort any previous ajax calls.
I think the below solutions may solve your issue:
Solution 1: Just Extentending what you have done:
var xhr
function repeatedCall() {
if(xhr){
// abort any previous calls, to avoid any inconsistency
xhr.abort()
}
xhr = $.ajax({
url: '/getUrl',
complete: function(data) {
if (data.statusText != "error") {
//my actions
}
}
})
}
setInterval(repeatedCall, 5000)
function updateData_function {
//I want to abort all previous ajax calls and make a new ajax call since it will update the data
if(xhr){
xhr.abort()
}
}
Solution 2: What I feel is a better approach
var xhr;
function repeatedCall() {
xhr = $.ajax({
url: '/getUrl',
complete: function(data) {
if (data.statusText != "error") {
//my actions
// Call the ajax call again:
setTimeout(repeatedCall, 5000)
}
}
})
}
function updateData_function {
//I want to abort all previous ajax calls and make a new ajax call since it will update the data
if(xhr){
xhr.abort()
}
// do something
}
// somewhere - to initiate the repeatedCall for the first time
repeatedCall()
I faced the same problem before as well and I was sending to many ajax calls on keyup which was leading my website to collapse. I found out the solution to setTimeout(); in to the ajax all firing and keeping firing the function clears timeout and settimeout again. This let you to fire ajax only 1 time on pressing to many time.
Edit: Ok for example I had a searchbox which was getting predefined suggestions with ajax call with onkeyup function. as I was start typing it was firing ajax call again and again and stucking. I started to cancel the one before as I firing another so fixed the situation. Here is the DEMO Doesnt matter how many time you hit the button it fires only one.
I've modified my code and this works
abortValue = false;
var xhr;
xhrPool = [];
var trying;
function abortAjax() {
$.each(xhrPool, function(idx, jqXHR) {
jqXHR.abort();
});
}
$(document).ready(function() {
fn = function() {
xhr = $.ajax({
url: '/getUrl',
beforeSend: function(jqXHR) {
xhrPool.push(jqXHR);
},
complete: function(jqXHR, data) {
if (abortValue == true) {
abortAjax()
} else {
if (jqXHR.statusText != "error" && "undefined") {
//myactions
}
}
}
});
};
var interval = setInterval(fn, 5000);
});
function updateData_function {
//I want to abort all previous ajax calls and make a new ajax call since it will update the data
abortValue = true;
abortAjax();
abortValue = false;
fn();
}
Is it possible that using jQuery, I cancel/abort an Ajax request that I have not yet received the response from?
Most of the jQuery Ajax methods return an XMLHttpRequest (or the equivalent) object, so you can just use abort().
See the documentation:
abort Method (MSDN). Cancels the current HTTP request.
abort() (MDN). If the request has been sent already, this method will abort the request.
var xhr = $.ajax({
type: "POST",
url: "some.php",
data: "name=John&location=Boston",
success: function(msg){
alert( "Data Saved: " + msg );
}
});
//kill the request
xhr.abort()
UPDATE:
As of jQuery 1.5 the returned object is a wrapper for the native XMLHttpRequest object called jqXHR. This object appears to expose all of the native properties and methods so the above example still works. See The jqXHR Object (jQuery API documentation).
UPDATE 2:
As of jQuery 3, the ajax method now returns a promise with extra methods (like abort), so the above code still works, though the object being returned is not an xhr any more. See the 3.0 blog here.
UPDATE 3: xhr.abort() still works on jQuery 3.x. Don't assume the update 2 is correct. More info on jQuery Github repository.
You can't recall the request but you can set a timeout value after which the response will be ignored. See this page for jquery AJAX options. I believe that your error callback will be called if the timeout period is exceeded. There is already a default timeout on every AJAX request.
You can also use the abort() method on the request object but, while it will cause the client to stop listening for the event, it may probably will not stop the server from processing it.
Save the calls you make in an array, then call xhr.abort() on each.
HUGE CAVEAT: You can abort a request, but that's only the client side. The server side could still be processing the request. If you are using something like PHP or ASP with session data, the session data is locked until the ajax has finished. So, to allow the user to continue browsing the website, you have to call session_write_close(). This saves the session and unlocks it so that other pages waiting to continue will proceed. Without this, several pages can be waiting for the lock to be removed.
It's an asynchronous request, meaning once it's sent it's out there.
In case your server is starting a very expensive operation due to the AJAX request, the best you can do is open your server to listen for cancel requests, and send a separate AJAX request notifying the server to stop whatever it's doing.
Otherwise, simply ignore the AJAX response.
AJAX requests may not complete in the order they were started. Instead of aborting, you can choose to ignore all AJAX responses except for the most recent one:
Create a counter
Increment the counter when you initiate AJAX request
Use the current value of counter to "stamp" the request
In the success callback compare the stamp with the counter to check if it was the most recent request
Rough outline of code:
var xhrCount = 0;
function sendXHR() {
// sequence number for the current invocation of function
var seqNumber = ++xhrCount;
$.post("/echo/json/", { delay: Math.floor(Math.random() * 5) }, function() {
// this works because of the way closures work
if (seqNumber === xhrCount) {
console.log("Process the response");
} else {
console.log("Ignore the response");
}
});
}
sendXHR();
sendXHR();
sendXHR();
// AJAX requests complete in any order but only the last
// one will trigger "Process the response" message
Demo on jsFiddle
We just had to work around this problem and tested three different approaches.
does cancel the request as suggested by #meouw
execute all request but only processes the result of the last submit
prevents new requests as long as another one is still pending
var Ajax1 = {
call: function() {
if (typeof this.xhr !== 'undefined')
this.xhr.abort();
this.xhr = $.ajax({
url: 'your/long/running/request/path',
type: 'GET',
success: function(data) {
//process response
}
});
}
};
var Ajax2 = {
counter: 0,
call: function() {
var self = this,
seq = ++this.counter;
$.ajax({
url: 'your/long/running/request/path',
type: 'GET',
success: function(data) {
if (seq === self.counter) {
//process response
}
}
});
}
};
var Ajax3 = {
active: false,
call: function() {
if (this.active === false) {
this.active = true;
var self = this;
$.ajax({
url: 'your/long/running/request/path',
type: 'GET',
success: function(data) {
//process response
},
complete: function() {
self.active = false;
}
});
}
}
};
$(function() {
$('#button').click(function(e) {
Ajax3.call();
});
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="button" type="button" value="click" />
In our case we decided to use approach #3 as it produces less load for the server. But I am not 100% sure if jQuery guarantees the call of the .complete()-method, this could produce a deadlock situation. In our tests we could not reproduce such a situation.
It is always best practice to do something like this.
var $request;
if ($request != null){
$request.abort();
$request = null;
}
$request = $.ajax({
type : "POST", //TODO: Must be changed to POST
url : "yourfile.php",
data : "data"
}).done(function(msg) {
alert(msg);
});
But it is much better if you check an if statement to check whether the ajax request is null or not.
Just call xhr.abort() whether it's jquery ajax object or native XMLHTTPRequest object.
example:
//jQuery ajax
$(document).ready(function(){
var xhr = $.get('/server');
setTimeout(function(){xhr.abort();}, 2000);
});
//native XMLHTTPRequest
var xhr = new XMLHttpRequest();
xhr.open('GET','/server',true);
xhr.send();
setTimeout(function(){xhr.abort();}, 2000);
You can abort any continuous ajax call by using this
<input id="searchbox" name="searchbox" type="text" />
<script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
<script type="text/javascript">
var request = null;
$('#searchbox').keyup(function () {
var id = $(this).val();
request = $.ajax({
type: "POST", //TODO: Must be changed to POST
url: "index.php",
data: {'id':id},
success: function () {
},
beforeSend: function () {
if (request !== null) {
request.abort();
}
}
});
});
</script>
As many people on the thread have noted, just because the request is aborted on the client-side, the server will still process the request. This creates unnecessary load on the server because it's doing work that we've quit listening to on the front-end.
The problem I was trying to solve (that others may run in to as well) is that when the user entered information in an input field, I wanted to fire off a request for a Google Instant type of feel.
To avoid firing unnecessary requests and to maintain the snappiness of the front-end, I did the following:
var xhrQueue = [];
var xhrCount = 0;
$('#search_q').keyup(function(){
xhrQueue.push(xhrCount);
setTimeout(function(){
xhrCount = ++xhrCount;
if (xhrCount === xhrQueue.length) {
// Fire Your XHR //
}
}, 150);
});
This will essentially send one request every 150ms (a variable that you can customize for your own needs). If you're having trouble understanding what exactly is happening here, log xhrCount and xhrQueue to the console just before the if block.
I was doing a live search solution and needed to cancel pending requests that may have taken longer than the latest/most current request.
In my case I used something like this:
//On document ready
var ajax_inprocess = false;
$(document).ajaxStart(function() {
ajax_inprocess = true;
});
$(document).ajaxStop(function() {
ajax_inprocess = false;
});
//Snippet from live search function
if (ajax_inprocess == true)
{
request.abort();
}
//Call for new request
Just use ajax.abort() for example you could abort any pending ajax request before sending another one like this
//check for existing ajax request
if(ajax){
ajax.abort();
}
//then you make another ajax request
$.ajax(
//your code here
);
there is no reliable way to do it, and I would not even try it, once the request is on the go; the only way to react reasonably is to ignore the response.
in most cases, it may happen in situations like: a user clicks too often on a button triggering many consecutive XHR, here you have many options, either block the button till XHR is returned, or dont even trigger new XHR while another is running hinting the user to lean back - or discard any pending XHR response but the recent.
The following code shows initiating as well as aborting an Ajax request:
function libAjax(){
var req;
function start(){
req = $.ajax({
url: '1.php',
success: function(data){
console.log(data)
}
});
}
function stop(){
req.abort();
}
return {start:start,stop:stop}
}
var obj = libAjax();
$(".go").click(function(){
obj.start();
})
$(".stop").click(function(){
obj.stop();
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="button" class="go" value="GO!" >
<input type="button" class="stop" value="STOP!" >
If xhr.abort(); causes page reload,
Then you can set onreadystatechange before abort to prevent:
// ↓ prevent page reload by abort()
xhr.onreadystatechange = null;
// ↓ may cause page reload
xhr.abort();
I had the problem of polling and once the page was closed the poll continued so in my cause a user would miss an update as a mysql value was being set for the next 50 seconds after page closing, even though I killed the ajax request, I figured away around, using $_SESSION to set a var won't update in the poll its self until its ended and a new one has started, so what I did was set a value in my database as 0 = offpage , while I'm polling I query that row and return false; when it's 0 as querying in polling will get you current values obviously...
I hope this helped
I have shared a demo that demonstrates how to cancel an AJAX request-- if data is not returned from the server within a predefined wait time.
HTML :
<div id="info"></div>
JS CODE:
var isDataReceived= false, waitTime= 1000;
$(function() {
// Ajax request sent.
var xhr= $.ajax({
url: 'http://api.joind.in/v2.1/talks/10889',
data: {
format: 'json'
},
dataType: 'jsonp',
success: function(data) {
isDataReceived= true;
$('#info').text(data.talks[0].talk_title);
},
type: 'GET'
});
// Cancel ajax request if data is not loaded within 1sec.
setTimeout(function(){
if(!isDataReceived)
xhr.abort();
},waitTime);
});
This is my implementation based on many answers above:
var activeRequest = false; //global var
var filters = {...};
apply_filters(filters);
//function triggering the ajax request
function apply_filters(filters){
//prepare data and other functionalities
var data = {};
//limit the ajax calls
if (activeRequest === false){
activeRequest = true;
}else{
//abort if another ajax call is pending
$request.abort();
//just to be sure the ajax didn't complete before and activeRequest it's already false
activeRequest = true;
}
$request = $.ajax({
url : window.location.origin + '/your-url.php',
data: data,
type:'POST',
beforeSend: function(){
$('#ajax-loader-custom').show();
$('#blur-on-loading').addClass('blur');
},
success:function(data_filters){
data_filters = $.parseJSON(data_filters);
if( data_filters.posts ) {
$(document).find('#multiple-products ul.products li:last-child').after(data_filters.posts).fadeIn();
}
else{
return;
}
$('#ajax-loader-custom').fadeOut();
},
complete: function() {
activeRequest = false;
}
});
}
In $.ajax there is beforeSend function, but now I'm trying to use XMLHttpRequest, I'm looking for equivalent function of beforeSend in $.ajax. How can i implement it in here.
Here is my xhr code,
xhr = new XMLHttpRequest();
var url = '../ajax/ajax_edit/update_ajax_staffUser.php';
if(file.files.length !== 0){
if(!check(fileUpload.type)){
alert("This file format not accepted");
return false;
}
xhr.open('post', url+param, true);
xhr.setRequestHeader('Content-Type','multipart/form-data');
xhr.setRequestHeader('X-File-Name', fileUpload.name);
xhr.setRequestHeader('X-File-Size', fileUpload.size);
xhr.setRequestHeader('X-File-Type', fileUpload.type);
xhr.send(fileUpload);
}else{
xhr.open('post', url+param, true);
xhr.setRequestHeader('Content-Type','multipart/form-data');
xhr.send(fileUpload);
}
xhr.onreadystatechange = function(e){
if(xhr.readyState===4){
if(xhr.status==200){
$('.bounce_dim').show();
setTimeout(function(){
$('.trigger_danger_alert_changable_success').show().delay(5000).fadeOut();
$('#palitan_ng_text_success').html('User successfully modified');
$('#frm_edit_staffUser')[0].reset();
$('#modal_staff').modal('hide');
$('.bounce_dim').hide();
},1000);
getUserStaffTable();
}
}
}
Since the users are uploading image to my web, I need to make a waiting interface before fires the call since the image size are too large.
You can do this by just putting the beforeSend() function before your XHR intantiation, like this:
beforeSend();
xhr = new XMLHttpRequest();
But you should define your beforeSend() function before the code above:
var beforeSend = function(){
// your code here
}
.beforeSend just calls the function before running .send, so just put your code before the line:
xhr.setRequestHeader('Content-Type','multipart/form-data');
xhr.setRequestHeader('X-File-Name', fileUpload.name);
xhr.setRequestHeader('X-File-Size', fileUpload.size);
xhr.setRequestHeader('X-File-Type', fileUpload.type);
beforeSend(); // Put any code to run before sending here
xhr.send(fileUpload);