how to control multiple ajax requests in laravel 5.2 - ajax

I am working on an application where different ajax requests fires depending upon different actions.
For example, there is a chat window having send button. When i click on that button an empty message is sent with ajax, successfully. It work nice. But when I hit the send button too many times, at start some requests respond 200 (ok) but then it respond 500 (internal server error). Due to this the other requests that are going continuously like updateLastActivity also disturb.
The preview of the error in developer's tool is:
Whoops like something went wrong.
Note: When I make this chat system in core PHP, it work fine. There is no internal server error when I send too may requests.
Here is the code I am using
//the following code is used to send the message
$(document).on('click','.send_message_bt',function(event){
event.preventDefault();
var id=$(this).data('id');
var name=$(this).data('name');
var message=$("#message_field-"+id).val();
$.ajax({
//headers: { 'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content') },
headers: { 'X-CSRF-TOKEN': {!! json_encode(csrf_token()) !!} },
url:'{{route('user.sendmessage')}}',
type:'POST',
data:{
id:id,
message:message
},
success:function(data,status){
//clear the message field value
$("#message_field-"+id).val('');
//update the chat history
fetchChatHistory(id,name);
},
error:function(response){
if(response.status==401){
alert('You are not logged in!');
window.location=window.location.href;
}
}
});
});
here is the back end code
public function sendMessage(Request $request){
$message=new Userchatmessage();
$message->message=$request->message;
$message->sender_id=Auth::user()->id;
$message->receiver_id=$request->id;
$message->save();
return response('success');
}
How to fix this issue.

I guess it's not a problem with Laravel or anything, but with your browser. Each browser has a maximum amount of simultaneous connections it will open for a certain domain.
Read more about this problem here and here.
If you want to make a realtime chat application, consider using something like NodeJS and Socket.io.

Async and await can help. Let an async function
async function doAjax(){
await runFirstAjaxCall();
await runAfterFirstAjaxCallSuccess();
....
....
}
doAjax();

Related

jQuery-Mobile: ajax request stops working after changePage failure

I am presently developing a web application with jQuery mobile. However, I found that when a "changePage" fails, I can no longer send ajax requests. After the failure, all ajax requests return an error. Here's the code executed when the submit button on the form is clicked (it's a basic user login screen):
// Event when user click the Submit login button
$('#submitLogin').on("click", function () {
// submit the user credentials to the server
$.ajax({
type: "POST",
url: "./LogUser",
data: {
EmployeeID: $('#EmployeeID').val(),
EmployeePIN: $('#EmployeePIN').val()
},
dataType: "text",
async: true,
cache: false,
error: function (rqst, text, thrownError) {
$('#dlg-login-error-message').text(thrownError);
$('#dlg-login-error-popup').popup("open");
},
success: function (data) {
if (data == "Success") {
$.mobile.changePage("./LoadScreen/Menu");
}
else {
$('#dlg-login-error-message').text(data);
$('#dlg-login-error-popup').popup("open");
}
}
});
return false;
});
If the post itself fails, I can resubmit without problem. If the .mobile.changePage fails, a "page not found" is displayed, but I am not able to resubmit, ajax no longer making request to the server and jumping directly to the error callback with a "not found" error.
I am guessing the problem comes from the fact that jQuery mobile uses AJAX request to load pages, and that somehow, ajax calls are getting mixed up somewhere.
I did more tests, even intercepted the pageloadfailed event, but nothing works. After the page change failure, AJAX calls no longer sends anything to the server and jump automatically to the error callback function.
I tried with async=false, same problem. I tried debugging jQuery-mobile, but I am still not able to find the "changePage" function itself ( the .code is quite confusing ).
I just spent the last two days trying to figure out a way to resolve this and I am seriously thinking of using something else than jQuery-mobile for our development.
I have found a workaround for my problem, but I do not know the full impact of this solution yet.
To prevent the problem, I had to set the "pushStateEnabled" configuration option to "false".
So if you find yourself with the same problem, try putting the following in a script right before the loading of the "jQuery-mobile" script.
$(document).bind("mobileinit", function () {
$.mobile.pushStateEnabled = false;
});
Example:
<!-- Load the script for jQuery -->
<script src="~/Scripts/jquery-2.1.4.js"></script>
<!-- Set default for jQuery-Mobile, before it is actually loaded -->
<script>
$(document).bind("mobileinit", function () {
$.mobile.pushStateEnabled = false;
});
</script>
<!-- Load the script for jQuery-Mobile -->
<script src="~/Scripts/jquery.mobile-1.4.5.js"></script>

Single Cross Domain AJAX Request needed

Trying to implement sending sms features in my ecommerce store.
I use service called esteria.lv and they provided me with API link that looks like this: http://api1.esteria.lv/send?api-key=api_key&sender=example.com&number=11223344&text=message
If the message is sent then it outputs message ID, now it outputs error number 3(unable to authenticate).
To get it working with my ecommerce store, I found this resource: http://www.ajax-cross-origin.com/examples/cross-origin.htm, and made this code:
$(function() {
$( '#btn' ).click(function(){
$.ajax({
crossOrigin: true,
url: 'http://api1.esteria.lv/send?api-key=api_key&sender=example.com&number=11223344&text=message',
success: function(data) {
$( '#test' ).html(data);
}
});
});
});
It works, but the problem is, it sends 6 messages (requests) instead of just one. I need just 1 request and one sent sms. Anyone have any suggestions?
To answer your comment, this is what you should do.
In your javascript you should have an ajax call to your server
// collect sms data
$.ajax({
url: 'yourserver/handlesms',
method: 'post',
data: {
sender: 'email#mail.com',
number: '1234567',
message: 'Test message'
}
}).then(function (data) {
alert("Message sent!");
});
In your server you should have an handler for sending the sms, something like (I don't know what's your platform, I'll just write a really simple php example)
$data = $_POST;
$apiKey = '12345643223213ds';
$endpoint = 'http://api1.esteria.lv/send';
// Create new curl request
$ch = curl_init($endpoint);
// curl settings, add your data, api key etc...
$result = curl_exec($ch);
// Result will contain the response from your api call
// Then you can send a result back to your client (js)
echo json_encode(['status' => 'Message sent!']);
This is just an example, the server code depends on your platform.
In this case you don't have any cross origin request (all the js request will be sent to your server, that then is in charge of contacting your sms provider and send the messages.
The problem that's executed 6 times I think depends on something else but it's hard to say without looking at the rest of the code (you can try debugging the click event on #btn and see how many times is executed every time you click on the button.

Chrome gives "XMLHttpRequest Exception 101" in some cases when doing an Ajax request

I have a JavaScript application that works like this:
Uploads a file, receives the uploaded file ID as a response
This is done using the BlueImp uploader
Uses the file ID to refer to the file in subsequent requests, in this case to receive a preview of the uploaded file.
This is the code for the file upload 'complete' handler. It's originally written in Coffee Script (http://pastebin.com/708Cf9tu).
var completeHandler = function(e, data) {
var url;
if (data.textStatus !== 'success') {
alert("Noe gikk galt. Debug informasjon er logget i konsollen");
console.group('Upload failure');
console.error(data.textStatus);
console.error(data.result);
console.groupEnd('Upload failure');
selectButton.removeClass('disabled');
uploadButton.removeClass('disabled loading');
uploadButton.html('Last opp');
return;
}
self.fileUploadResponse = data.result;
url = "" + config.api_root + "/" + config.api_path_tabulardatafilepreview;
return $.ajax(url, {
type: 'POST',
dataType: 'json',
async: false,
data: {
'file_handle': data.result.file_handle,
'rownum': 5
},
complete: function(req, text_status) {
if (text_status !== 'success') {
alert("Noe gikk galt. Debug informasjon er logget " + "i konsollen");
console.group('Failed to receive data file preview');
console.log(text_status);
console.log(req.responseText);
console.log(req);
console.groupEnd('Failed to receive data file preview');
selectButton.removeClass('disabled');
uploadButton.removeClass('disabled loading');
uploadButton.html('Last opp');
}
self.previewData = JSON.parse(req.responseText);
return self.setStage(2);
}
});
};
This works brilliantly in FireFox, but in Chrome I just started to get an error in the second jQuery Ajax request. It now returns with status "error", with no responseText and with statusText set to "Error: NETWORK_ERR: XMLHttpRequest Exception 101". Though this doesn't happen in all cases. The uploaded file doesn't seem to have anything to do with the issue, because a 10KB csv file works, a 120KB xlsx file fails but a 1.2MB xlsx works. Additionally it's the second Ajax request that fails, and it doesn't do anything but send two small integers to the server. Why does that fail!?
Also this just started happening today. I haven't changed anything that I know of, and I have not updated Chrome.
Does anyone have a clue as to why Chrome is doing this? Can it have anything to do with an Ajax request being launched in the complete handler of a previous Ajax request?
Thanks for any guesses that can help me solve this
Turns out it's a bad idea to start lengthy processes inside Ajax event handlers. In my case, starting a new synchronous Ajax request in the event handler was the mistake. I have since made both requests asynchronous and separated the code into neat functions, and I'm no longer bothered by the exception.

JQuery $.post() doesn't work

Can any one help me with the following code:
$(document).ready(function() {
$("#add_user").submit(function() {
$.post( "../php/register_sql_ins.php",
{r_fname: $("#fname").val(),
r_lname: $("#lname").val(),
r_uname: $("#uname").val(),
r_pass: $("#pass").val(),
r_authLevel: $("#authLevel").val(),
r_email: $("#email").val(),
r_company: $("#company").val(),
r_phone: $("#phone").val(),
r_address: $("#add").val()}, function(result) {
alert(result);
}
);
return false;
});
});
This should store my user data in a sql table. the php part of code(register_sql_ins.php) works fine. but this query piece of code just doesn't work!! and I have no idea what is the problem!
With Firebug it returns false every time!
By the way sorry for bad english. It's not my mother tong!
There are two places where I would look for the cause of such error:
Network tab in Firebug. Check what is sent to the server and what is the response. If data sent is correct and server replies with status 200, then you have to debug your PHP script, else
Server logs. If the request failed to complete succesfully, log will contain the reason.

Django Posts Not Working:

I am using Django 1.2.3 to develop a site. My ajax get requests work fine but the post requests work in development mode (127.0.0.1:8000) but not when I push the site into production using apache + nginx.
Here is an example
urls.py:
(r'api/newdoc/$', 'mysite.documents.views.newdoc'),
views.py
def newdoc(request):
# only process POST request
if request.is_ajax():
data= dict(request.POST)
# save data to db
return HttpResponse(simplejson.dumps([True]))
in javascript:
$.post("/api/newdoc/", {data : mydata}, function(data) { alert(data);}, "json");
my alert is never called .... this is a problem because i want to sanitize this data via a django form and the post requests do not seem to making it to the server (in production only).
what am i doing wrong?
UPDATES:
solution: crsf tokens need to be pushed ajax post requests (not gets) as of django 1.3
also, per the link provide below, the following javascript
$.ajaxSetup({
beforeSend: function(xhr, settings) {
if (!(/^http:.*/.test(settings.url) || /^https:.*/.test(settings.url))) {
// Only send the token to relative URLs i.e. locally.
xhr.setRequestHeader("X-CSRFToken",
$("#csrfmiddlewaretoken").val());
}
}
});
needs to be changed as follows:
$.ajaxSetup({
beforeSend: function(xhr, settings) {
if (!(/^http:.*/.test(settings.url) || /^https:.*/.test(settings.url))) {
// Only send the token to relative URLs i.e. locally.
xhr.setRequestHeader("X-CSRFToken",
$('input[name="csrfmiddlewaretoken"]').val());
}
}
});
the way the csrf token gets rendered in the form must have changed between 1.25 - 1.3??
regardless, it works. thanks for all your help everyone
Can you directly access your javascript files from the production server? Which Django version are you using in production? If you are using 1.2.5+ in production, you will need to push the csrf token to the server during an AJAX post operation.
See the release notes in 1.2.5 and CSRF
To check your Django version:
import django
django.get_version()
Print the above in your production site or from the shell in your production server while making sure you are using the proper Python path.
Your code appears fine with a cursory glance, but I'll show you an example of my ajax form processing code in a hope it'll help with figuring out the error that's occurring. Though, what #dmitry commented should be your first debugging step - use firebug or the inspector to see if the ajax call returns an error.
// js (jQuery 1.5)
$(form).submit(function(event) {
event.preventDefault();
$.post(post_url, $(form).serialize())
.success(function(data, status, jqxhr) {
if (data.success) { // form was valid
$(form)
// other irrelevant code
.siblings('span')
.removeClass('error')
.html('Form Successful');
} else { // form was invalid
$(form).siblings('span').addClass('error').html('Error Occurred');
}
})
.error(function(jqxhr, status, error) { // server error
$(form).siblings('span').addClass('error').html("Error: " + error);
});
});
// django
class AjaxFormView(FormView):
def ajax_response(self, context, success=True):
html = render_to_string(self.template_name, context)
response = simplejson.dumps({'success': success, 'html': html})
return HttpResponse(response, content_type="application/json", mimetype='application/json')
// view deriving from AjaxFormView
def form_valid(self, form):
registration = form.save()
if self.request.is_ajax():
context = {'competition': registration.competition }
return self.ajax_response(context, success=True)
return HttpResponseRedirect(registration.competition.get_absolute_url())
def form_invalid(self, form):
if self.request.is_ajax():
context = { 'errors': 'Error Occurred'}
return self.ajax_response(context, success=False)
return render_to_response(self.template_name, {'errors':form.errors})
Actually, comparing the above to your code, you may need to set the content_type in your django view so that jQuery can understand and process the response. Note that the above is using django 1.3 class-based views, but the logic should be familiar regardless. I use context.success to signal if the form processing passed or failed - since a valid response (json) of any kind will signal the jQuery.post that the request was successful.

Resources