WP Shortcodes not being added

I was creating a wordpress plugin where the user enters in some information, and is able to generate shortcodes. I was not quite sure where the shortcodes are supposed to go - my current setup is class-based, and I want to be able to create a shortcode when an AJAX request is being made, and is successful. The following two methods are in the same file in the class.

This method gets called via the admin-ajax.php file:

public static function processAjax()
{

    global $wpdb;
    $event_data = $_POST['obj'];

    $event_title = $event_data[0];
    $event_subdomain = $event_data[1];
    $result_events = $wpdb->get_results("SELECT * FROM wp_shortcode_plugin WHERE subdomain = '{$event_subdomain}'", OBJECT);
    if (sizeof($result_events)>0) {
        echo "duplicate";
    } else {
        add_shortcode($event_subdomain, 'getEmbed');
        $results = $wpdb->insert('wp_shortcode_plugin', array("event_name"=>$event_title, "subdomain"=>$event_subdomain));
        echo json_encode($_POST['obj']);
    }

    die();
}

And here is my getEmbed() method that I would like to call.

public static function getEmbed()
{
    return 'test';
}

It seems that the shortcodes are not being created, however. Am I missing something here? Also, is it possible to pass a value to the getEmbed function from the add_shortcode() method?

via Chebli Mohamed