Joomla Ajax Module getAjax() method not found

Question

I have no experience with Ajax and little to no experience with Joomla. I've managed to create my own Joomla modules with no problem. Today I tried to use Ajax in one of my modules but I am getting an error: "Method getAjax does not exist.".

Here is my helper.php

<?php

class ModDisplayVacancies
{
    public static function getAjax()
    {
       return "getAjax return";
    }

....
}

my mod_display_vacancies.php

<?php

// No direct access
defined('_JEXEC') or die;
// Include the syndicate functions only once

$document = JFactory::getDocument();
require_once dirname(__FILE__) . '/helper.php';


$document->addStyleSheet('/Joomla/modules/mod_display_vacancies/css/styles.css');
$document->addScript('/Joomla/modules/mod_display_vacancies/js/custom.js');


$table = ModDisplayVacancies::createTable($params);

require JModuleHelper::getLayoutPath('mod_display_vacancies');

And my JavaScript:

jQuery(document).on('click', 'button[id=vacancies_next]', function(){

    console.log("next");

    var request = {
        'option' : 'com_ajax',
        'module' : 'display_vacancies',
        'data' : 5,
        'format': 'json'
    }

    jQuery.ajax({
        type: 'GET',
        data: request,
        success:function(responce){
            console.log("success");
            console.log(responce);
        },
        error:function(responce){
            console.log("error");
            console.log(responce);
        }
    });  


});

It's pretty strange to me why in the console I'm getting "success" and then an error:

Answer 1

Your Helper Class name should be:

ModDisplayVacanciesHelper

And the Module must be published on all pages, if not you have to add one menu ID in your request where the module is published. Just like this:

&Itemid=<menu id>