Develop Reference

Ajax callback is firing after function call

Hi Have a ajax call in a function thats called on date input change event to check if a date is already in use for User. the success in the Ajax call fires after the click function is finished.
How do I get the success results and continue on with the #datepicker change funtion as I need the json results for rest of function.
controller
public ActionResult IsDateAvailable(DateTime date, int Id) {
var dateAvailable = !(_context.Trading.Any(t => t.uId == Id && t.TradingDate == date));
if (!(dateAvailable)) {
return Json(new {
status = false, msg = "This date already exists."
});
}
return Json(new {
status = true
});
}
JavaScript
$(document).ready(function() {
var message;
var isDateValid;
function CheckDate(para) {
var dateValid;
var mesg;
return $.ajax({
url: '#Url.Action("IsDateAvailable", "Trading")',
type: "GET",
data: para,
dataType: "json",
success: function(data) {
if (!(data.status)) {
message = data.msg;
} else {
isDateValid = true;
}
},
error: function(xhr, httpStatusMessage) {
alert(xhr + httpStatusMessage);
}
});
}
$("#datePicker").change(function() {
$("#alert").css({
'display': 'none'
});
if (Id == 0) {
$("#alert").attr('class', 'alert alert-danger');
$("#alert").text('Please select a User.');
$("#alert").show();
return false;
}
var date = $(this).val();
var para = {
date: date,
Id: Id
};
CheckDate(para);
if (isDateValid) {
$("#btnAdd").show();
} else {
$("#btnAdd").css({
'display': 'none'
});
$("#alert").attr('class', 'alert alert-danger');
$("#alert").text(message);
$("#alert").show();
}
});
});

You should turn to being asynchronous. change your code to match with these:
.
.
.
function CheckDate(para) {
return new Promise((resolve, reject) => {
return $.ajax({
url: '#Url.Action("IsDateAvailable", "Trading")',
type: "GET",
data: para,
dataType: "json",
success: function(data) {
if (!(data.status)) {
message = data.msg;
} else {
isDateValid = true;
}
resolve();
},
error: function(xhr, httpStatusMessage) {
alert(xhr + httpStatusMessage);
reject();
}
});
}
.
.
.
checkDate(para).then(res => {
if (isDateValid) {
$("#btnAdd").show();
} else {
$("#btnAdd").css({
'display': 'none'
});
$("#alert").attr('class', 'alert alert-danger');
$("#alert").text(message);
$("#alert").show();
}
}).catch(err => { /* do something */ });

You just need to set async: false inside your ajax request. You can also remove the word return from the CheckDate, because of it's redundant:
function CheckDate(para) {
var dateValid;
var mesg;
$.ajax({
url: '#Url.Action("IsDateAvailable", "Trading")',
async: false,
type: "GET",
data: para,
dataType: "json",
success: function(data) {
if (!(data.status)) {
message = data.msg;
} else {
isDateValid = true;
}
},
error: function(xhr, httpStatusMessage) {
alert(xhr + httpStatusMessage);
}
});
}

javascript works on localhost but fails on hosting server

When i click on add-to-basket button i see an error which appears in my browser console saying :
Here is my basket.js file :
$(document).ready(function() {
initBinds();
function initBinds() {
if ($('.remove_basket').length > 0) {
$('.remove_basket').bind('click', removeFromBasket);
}
if ($('.update_basket').length > 0) {
$('.update_basket').bind('click', updateBasket);
}
if ($('.fld_qty').length > 0) {
$('.fld_qty').bind('keypress', function(e) {
var code = e.keyCode ? e.keyCode : e.which;
if (code == 13) {
updateBasket();
}
});
}
}
function removeFromBasket() {
var item = $(this).attr('rel');
$.ajax({
type: 'POST',
url: '/home/u919084925/public_html/mod/basket_remove.php',
dataType: 'html',
data: ({ id: item }),
success: function() {
refreshBigBasket();
refreshSmallBasket();
},
error: function() {
alert('An error has occurred');
}
});
}
function refreshSmallBasket() {
$.ajax({
url: '/home/u919084925/public_html/mod/basket_small_refresh.php',
dataType: 'json',
success: function(data) {
$.each(data, function(k, v) {
$("#basket_left ." + k + " span").text(v);
});
},
error: function(data) {
alert("An error has occurred");
}
});
}
function refreshBigBasket() {
$.ajax({
url: '/home/u919084925/public_html/mod/basket_view.php',
dataType: 'html',
success: function(data) {
$('#big_basket').html(data);
initBinds();
},
error: function(data) {
alert('An error has occurred');
}
});
}
if ($(".add_to_basket").length > 0) {
$(".add_to_basket").click(function() {
var trigger = $(this);
var param = trigger.attr("rel");
var item = param.split("_");
$.ajax({
type: 'POST',
url: '/home/u919084925/public_html/mod/basket.php',
dataType: 'json',
data: ({ id : item[0], job : item[1] }),
success: function(data) {
var new_id = item[0] + '_' + data.job;
if (data.job != item[1]) {
if (data.job == 0) {
trigger.attr("rel", new_id);
trigger.text("Remove from basket");
trigger.addClass("red");
} else {
trigger.attr("rel", new_id);
trigger.text("Add to basket");
trigger.removeClass("red");
}
refreshSmallBasket();
}
},
error: function(data) {
alert("An error has occurred");
}
});
return false;
});
}
function updateBasket() {
$('#frm_basket :input').each(function() {
var sid = $(this).attr('id').split('-');
var val = $(this).val();
$.ajax({
type: 'POST',
url: '/home/u919084925/public_html/mod/basket_qty.php',
data: ({ id: sid[1], qty: val }),
success: function() {
refreshSmallBasket();
refreshBigBasket();
},
error: function() {
alert('An error has occurred');
}
});
});
}
// proceed to paypal
if ($('.paypal').length > 0) {
$('.paypal').click(function() {
var token = $(this).attr('id');
var image = "<div style=\"text-align:center\">";
image = image + "<img src=\"/images/loadinfo.net.gif\"";
image = image + " alt=\"Proceeding to PayPal\" />";
image = image + "<br />Please wait while we are redirecting you to PayPal...";
image = image + "</div><div id=\"frm_pp\"></div>";
$('#big_basket').fadeOut(200, function() {
$(this).html(image).fadeIn(200, function() {
send2PP(token);
});
});
});
}
function send2PP(token) {
$.ajax({
type: 'POST',
url: '/mod/paypal.php',
data: ({ token : token }),
dataType: 'html',
success: function(data) {
$('#frm_pp').html(data);
// submit form automatically
$('#frm_paypal').submit();
},
error: function() {
alert('An error has occurred');
}
});
});
I tried to resolve it but couldn't find a proper solution.
Help me with this, I cannot understand the cause of this error.

This is mainly due to Rules of Origins (CORS), for some reason the javascript(browser) sees the request as not residing in the same server. And the reason for that, I believe, is because /home/u919084925/public_html/mod/basket.php is not seen as a valid url on the server, it should start with http://{hostname}/{path}.

It looks like your ajax url is totally wrong and the browser interpret that is cross origin ajax request. Please simply check in browser's address bar if your ajax provided urls are valid.

How do I throw an error message within AJAX?

For some reason I can't throw an error message to say whether or not an email exists inside of my user table. I understand that because AJAX is async I can't use try and catch error messages inside the complete function. But I tried splitting it into functions and it still doesn't work.
Try, Catch Function (I do call this else where in my code)
try {
// Check fields are not empty
if (!firstName || !lastName || !aquinasEmail || !sPassword || !sCPassword || !Gender) {
throw "One or more field(s) have been left empty.";
}
// Check the email format is '#aquinas.ac.uk'
if(!emailCheck.test(aquinasEmail)) {
throw "The email address you entered has an incorrect email prefix. ";
}
// Check there are not any numbers in the First or Last name
if (!regx.test(firstName) || !regx.test(lastName)) {
throw "First Name or Last Name is invalid.";
}
// Check the confirmation password is the same as the first password
if (sPassword != sCPassword) {
throw "The two passwords you've entered are different.";
}
if(duplicatedEmail()) {
throw "Sadly, your desired email is taken. If you have forgotten your password please, Click Here";
}
} catch(err) {
if (!error) {
$('body').prepend("<div class=\"error alert\">"+err+"</div>");
$('.signupInput.sPassword').val('');
$('.signupInput.sCPassword').val('');
setTimeout(function() {
$('.error.alert').fadeOut('1000', function() {$('.error.alert').remove();});
}, 2600);
}
event.preventDefault();
}
AJAX Function:
function duplicatedEmail() {
// Use AJAX function to do verification checks which can not be done via jQuery.
$.ajax({
type: "POST",
url: "/login/ajaxfunc/verifyReg.php",
dataType: "JSON",
async: false,
data: $('.signupForm').serialize(),
success: function(data) {
if (data.emailTaken == true) {
return true;
} else {
return false;
}
}
});
}
verifyReg.php
<?php
header('Content-Type: application/json', true);
$error = array();
require_once '../global.php';
$_POST['aquinas-email'] = "aq142647#aquinas.ac.uk";
// Check if an email already exists.
$checkEmails = $db->query("SELECT * FROM users WHERE aquinasEmail = '{$_POST['aquinas-email']}'");
if ($db->num($checkEmails) > 0) {
$error['emailTaken'] = true;
} else {
$error['emailTaken'] = false;
}
echo json_encode($error);
?>

to handle the error with jquery ajax function add error callback like this
function duplicatedEmail() {
// Use AJAX function to do verification checks which can not be done via jQuery.
$.ajax({
type: "POST",
url: "/login/ajaxfunc/verifyReg.php",
dataType: "JSON",
async: false,
data: $('.signupForm').serialize(),
success: function(data) {
if (data.emailTaken == true) {
return true;
} else {
return false;
}
},
error: function() {
//Your Error Message
console.log("error received from server");
}
});
}
to throw an exception in your PHP:
throw new Exception("Something bad happened");

Looking at your AJAX Function, and these two answers here and here, you need to make a small change to how you are returning the synchronous result:-
function duplicatedEmail() {
var result;
$.ajax({
type: "POST",
url: "/login/ajaxfunc/verifyReg.php",
dataType: "JSON",
async: false,
data: $('.signupForm').serialize(),
success: function(data) {
result = data.emailTaken;
}
});
return result;
}

use ajax error function..
function duplicatedEmail() {
// Use AJAX function to do verification checks which can not be done via jQuery.
$.ajax({
type: "POST",
url: "/login/ajaxfunc/verifyReg.php",
dataType: "JSON",
async: false,
data: $('.signupForm').serialize(),
success: function(data) {
if (data.emailTaken == true) {
return true;
} else {
return false;
}
},
error: function (result) {
alert("Error with AJAX callback"); //your message
}
});
}

Ajax success function not working in jquery mobile

I am trying to validate a basic login form with username and password fields. I need to validate username and password from check.php ajax page. There is no problem in ajax request and response. I am getting proper response from ajax page. But Ajax success function is not working properly.
ajaxrequest.html
$(document).on('pagebeforeshow', '#login', function(){
$(document).on('click', '#submit', function() {
if($('#username').val().length > 0 && $('#password').val().length > 0){
$.ajax({
url : 'serverurl/check.php',
data: {action : 'login', formData : $('#check-user').serialize()},
type: 'post',
beforeSend: function() {
$.mobile.loading(true);
alert("beforesend");
},
complete: function() {
$.mobile.loading(false);
alert("complete");
},
success: function (result) {
console.log("Ajax response");
res = JSON.stringify(result);
if(res.status == "success"){
resultObject.formSubmitionResult = res.uname;
localStorage["login_details"] = window.JSON.stringify(result);
$.mobile.changePage("#second");
}else{
$.mobile.changePage("#login");
alert("incorrect login");
}
},
error: function (request,error) {
alert('Network error has occurred please try again!');
}
});
} else {
alert('Fill all fields');
}
return false;
});
});
Here i have added my ajax page. This page only validates posted username and password. Finally it returns json object. What am i doing wrong?
serverurl/check.php
header("Access-Control-Allow-Origin: *");
header('Content-Type: application/json');
if(isset($_POST['formData']) && isset($_POST['action']) && $_POST['action'] == 'login'){
parse_str($_POST['formData'],$searchArray);
$uname = "arun";
$pwd = "welcome";
$resultArray = array();
if($uname == $searchArray['username'] && $pwd == $searchArray['password'])
{
$resultArray['uname'] = $searchArray['username'];
$resultArray['pwd'] = $searchArray['password'];
$resultArray['status'] = 'success';
}else{
$resultArray['status'] = 'failed';
}
echo json_encode($resultArray);
}

Your code should be
success: function (result) {
console.log("Ajax response");
//don't do this
//res = JSON.stringify(result);
if(result.status == "success"){
resultObject.formSubmitionResult = result.uname;
localStorage["login_details"] = window.JSON.stringify(result);
$.mobile.changePage("#second");
}else{
$.mobile.changePage("#login");
alert("incorrect login");
}
After JSON.stringify you are accessing like stringJson.status this will not work. it mast have "parsed" "json object" not stringify.

Don't need to convert your JSON to String.
$(document).on('pagebeforeshow', '#login', function(){
$(document).on('click', '#submit', function() {
if($('#username').val().length > 0 && $('#password').val().length > 0){
$.ajax({
url : 'serverurl/check.php',
data: {action : 'login', formData : $('#check-user').serialize()},
type: 'post',
beforeSend: function() {
$.mobile.loading(true);
alert("beforesend");
},
complete: function() {
$.mobile.loading(false);
alert("complete");
},
success: function (result) {
console.log("Ajax response");
//Don't need to converting JSON to String
//res = JSON.stringify(result);
//directly use result
if(result.status == "success"){
resultObject.formSubmitionResult = result.uname;
localStorage["login_details"] = window.JSON.stringify(result);
$.mobile.changePage("#second");
}else{
$.mobile.changePage("#login");
alert("incorrect login");
}
},
error: function (request,error) {
alert('Network error has occurred please try again!');
}
});
} else {
alert('Fill all fields');
}
return false;
});
});

Your AJAX call is perfect but datatype is not declared in ajax
Try with jSON OR JSONP. You will get success.
$.ajax({
url : 'serverurl/check.php',
type: 'post',
dataType: "json", OR "jsonp",
async: false,
data: {action : 'login', formData : $('#check-user').serialize()},
beforeSend: function() {
$.mobile.loading(true);
alert("beforesend");
},
complete: function() {
$.mobile.loading(false);
alert("complete");
},
success: function (result) {
console.log("Ajax response");
alert(JSON.stringify(result)); // Check response in alert then parse according to that
res = JSON.stringify(result);
if(res.status == "success"){
resultObject.formSubmitionResult = res.uname;
localStorage["login_details"] = window.JSON.stringify(result);
$.mobile.changePage("#second");
}else{
$.mobile.changePage("#login");
alert("incorrect login");
}
},
error: function (request,error) {
alert('Network error has occurred please try again!');
}
});

Under some circumstances your server might not return the response correctly. Have you tried to handle the actual response code (e.g. if your server returns 200) like this:
$.ajax({
url : 'serverurl/check.php',
data: {action : 'login', formData : $('#check-user').serialize()},
type: 'post',
....
statusCode: {
200: function (response) {
// do your stuff here
}
}
});

event.preventDefault(); only works some of the time with submit form

I am using the Mailchimp API to submit a form. The goal is to prevent the default callback provided by Mailchimp. The majority of the time event.preventDefault() is behaving as it should. Then randomly it will not work:
$(function () {
var $form = $('#mc-embedded-subscribe-form');
$('#mc-embedded-subscribe').on('click', function(event) {
if(event) event.preventDefault();
register($form);
});
});
function register($form) {
$.ajax({
type: $form.attr('method'),
url: $form.attr('action'),
data: $form.serialize(),
cache : false,
dataType : 'json',
contentType: "application/json; charset=utf-8",
error : function(err) { alert("Could not connect to the registration server. Please try again later."); },
success : function(data) {
if (data.result != "success") {
// Something went wrong, do something to notify the user. maybe alert(data.msg);
var message = data.msg
var messageSh = data.msg.substring(4);
if (data.msg == '0 - Please enter a value' || data.msg == '0 - An email address must contain a single #') {
$('#notification_container').html('<span class="alert">'+messageSh+'</span>');
} else {
$('#notification_container').html('<span class="alert">'+message+'</span>');
}
} else {
// It worked, carry on...
var message = data.msg;
$('.popup-promo-container').addClass('thanks');
$('.checkboxes, #mc_embed_signup_scroll').addClass('hidden');
$('.complete-promo').html(message).removeClass('hidden');
setTimeout(function() {
document.querySelector('.popup-promo').style.display = "none";
},20000);
}
}
});
}

Try
take off ready function.
remove if on event
Code:
var $form = $('#mc-embedded-subscribe-form');
$('#mc-embedded-subscribe').on('click', function(event) {
event.preventDefault();
register($form);
});