Saving an ajax datatable back to the database with php - php

Question

So I'm working with datatables and where I can edit the values in the datatables. I ran into a problem with actually saving the changes, at first this method worked but when I came back the next day it just didn't want to work anymore.
Is there anything obvious I'm missing here? Or is there something more to the story?
Server side code:
case 'form_save': {
$form_id = !empty($post['form_id']) ? $post['form_id'] : false;
$data = array();
$where = array('id'=>$this->db->escape($post['id']));
if(!empty($form_id)) {
switch($form_id) {
case 'translations': {
$data['value'] = $this->db->escape($post['value']);
$rc['success'] = $this->db->update('translations',$data,$where);
break;
}
case 'carousel': {
$data['title'] = $this->db->escape($post['title']);
$data['src'] = $this->db->escape($post['src']);
$data['alt'] = $this->db->escape($post['alt']);
$data['slide_url'] = $this->db->escape($post['slide_url']);
$data['slide_order'] = $this->db->escape($post['slide_order']);
$rc['success'] = $this->db->update('carousel',$data,$where);
break;
}
}
}
JQuery code:
$(document).on('submit','form',function(){
var $form = $(this);
var $error = $form.find('div.error');
var form_id = $form.attr('id');
var $modal = $(document).find('.modal');
var data = $form.serializeArray();
data.form_id = form_id;
data.type = 'form_save';
$.post('/admin_get/',data,function(rc){
if(rc.success) {
$modal.modal('hide');
$modal.find('modal-title').html('');
$modal.find('modal-body').html('');
} else {
$error.html(rc.error).show();
$error.html('').hide();
}
},'json');
});
});
EDIT: forgot to add the edit form jquery side :
$(document).on("click", ".edit", function(){
var id = $(this).data('id');
var table = $(this).closest('table').attr('id');
var $modal = $(document).find('.modal');
$.post('/admin_get/', {id:id, type:'get_form', table:table}, function(data){
$modal.find('.modal-title').html(data.title);
$modal.find('.modal-body').html(data.html);
$modal.find('.modal-body').find('#summernote').summernote();
$modal.find('.modal-body').find('.select2').select2();
$modal.modal('show');
},'json');
});