[jquery] jQuery - Illegal invocation

jQuery v1.7.2

I have this funcion that is giving me the following error while executing :

Uncaught TypeError: Illegal invocation

Here's the function :

$('form[name="twp-tool-distance-form"]').on('submit', function(e) {
    e.preventDefault();

    var from = $('form[name="twp-tool-distance-form"] input[name="from"]');
    var to = $('form[name="twp-tool-distance-form"] input[name="to"]');
    var unit = $('form[name="twp-tool-distance-form"] input[name="unit"]');
    var speed = game.unit.speed($(unit).val());

    if (!/^\d{3}\|\d{3}$/.test($(from).val()))
    {
        $(from).css('border-color', 'red');
        return false;
    }

    if (!/^\d{3}\|\d{3}$/.test($(to).val()))
    {
        $(to).css('border-color', 'red');
        return false;
    }

    var data = {
        from : from,
        to : to,
        speed : speed
    };

    $.ajax({
        url : base_url+'index.php',
        type: 'POST',
        dataType: 'json',
        data: data,
        cache : false
    }).done(function(response) {
        alert(response);
    });

    return false;
});

If I remove data from ajax call, it works .. any suggestions?

Thanks!

If you want to submit a form using Javascript FormData API with uploading files you need to set below two options:

processData: false,
contentType: false

You can try as follows:

//Ajax Form Submission
$(document).on("click", ".afs", function (e) {
    e.preventDefault();
    e.stopPropagation();
    var thisBtn = $(this);
    var thisForm = thisBtn.closest("form");
    var formData = new FormData(thisForm[0]);
    //var formData = thisForm.serializeArray();

    $.ajax({
        type: "POST",
        url: "<?=base_url();?>assignment/createAssignment",
        data: formData,
        processData: false,
        contentType: false,
        success:function(data){
            if(data=='yes')
            {
                alert('Success! Record inserted successfully');
            }
            else if(data=='no')
            {
                alert('Error! Record not inserted successfully')
            }
            else
            {
                alert('Error! Try again');
            }
        }
    });
});

In my case (using webpack 4) within an anonymous function, that I was using as a callback.

I had to use window.$.ajax() instead of $.ajax() despite having:

import $ from 'jquery';
window.$ = window.jQuery = $;

In My case I have't define all variables which I am passing to data in ajax.

var page = 1;

$.ajax({
    url: 'your_url',
    type: "post",
    data: { 'page' : page, 'search_candidate' : search_candidate }
    success: function(result){
        alert('function called');
    }
)}

I have just defined variable var search_candidate = "candidate name"; and its working.

var page = 1;
var search_candidate = "candidate name"; // defined
$.ajax({
    url: 'your_url',
    type: "post",
    data: { 'page' : page, 'search_candidate' : search_candidate }
    success: function(result){
        alert('function called');
    }
)}

Also this is a cause too: If you built a jQuery collection (via .map() or something similar) then you shouldn't use this collection in .ajax()'s data. Because it's still a jQuery object, not plain JavaScript Array. You should use .get() at the and to get plain js array and should use it on the data setting on .ajax().

Try to set processData: false in ajax settings like this

$.ajax({
    url : base_url+'index.php',
    type: 'POST',
    dataType: 'json',
    data: data,
    cache : false,
    processData: false
}).done(function(response) {
    alert(response);
});

In my case, I just changed

Note: This is in case of Django, so I added csrftoken. In your case, you may not need it.

Added contentType: false, processData: false

Commented out "Content-Type": "application/json"

$.ajax({
    url: location.pathname, 
    type: "POST",
    crossDomain: true,
    dataType: "json",
    headers: {
        "X-CSRFToken": csrftoken,
        "Content-Type": "application/json"
    },
    data:formData,
    success: (response, textStatus, jQxhr) => {

    },
    error: (jQxhr, textStatus, errorThrown) => {

    }
})

to

$.ajax({
    url: location.pathname, 
    type: "POST",
    crossDomain: true,
    dataType: "json",
    contentType: false,
    processData: false,
    headers: {
        "X-CSRFToken": csrftoken
        // "Content-Type": "application/json",
    },
    data:formData,
    success: (response, textStatus, jQxhr) => {

    },
    error: (jQxhr, textStatus, errorThrown) => {

    }
})

and it worked.

Just for the record it can also happen if you try to use undeclared variable in data like

var layout = {};
$.ajax({
  ...
  data: {
    layout: laoyut // notice misspelled variable name
  },
  ...
});

My problem was unrelated to processData. It was because I sent a function that cannot be called later with apply because it did not have enough arguments. Specifically I shouldn't have used alert as the error callback.

$.ajax({
    url: csvApi,
    success: parseCsvs,
    dataType: "json",
    timeout: 5000,
    processData: false,
    error: alert
});

See this answer for more information on why that can be a problem: Why are certain function calls termed "illegal invocations" in JavaScript?

The way I was able to discover this was by adding a console.log(list[ firingIndex ]) to jQuery so I could track what it was firing.

This was the fix:

function myError(jqx, textStatus, errStr) {
    alert(errStr);
}

$.ajax({
    url: csvApi,
    success: parseCsvs,
    dataType: "json",
    timeout: 5000,
    error: myError // Note that passing `alert` instead can cause a "jquery.js:3189 Uncaught TypeError: Illegal invocation" sometimes
});