popup auto redirect to undefined controller - html

Question

i want to update data "barang" using pop up.
before the pop up goes down completely, the page redirect http://localhost/koperasi/index.php/cukl/undefined & show
" The page you requested was not found" error.
....
this is my controller
public function ubahbarang(){
if ($this->input->post('ubahdatabarang')) {
$id_barang=$this->input->post('id_barang');
$id_jenis=$this->input->post('id_jenis');
$nm_barang=$this->input->post('nm_barang');
$stok=$this->input->post('stok');
$hrg_beli=$this->input->post('hrg_beli');
$hrg_jual=$this->input->post('hrg_jual');
$this->barang->mengubah_barang($id_barang, $id_jenis, $nm_barang, $stok, $hrg_beli, $hrg_jual);
redirect('cukl', 'refresh');
}
}
....
this is my model
public function mengubah_barang($id_barang, $id_jenis, $nm_barang, $stok, $hrg_beli, $hrg_jual)
{
$hasil = $this->db->query("UPDATE barang SET id_barang='$id_barang', id_jenis='$id_jenis', nm_barang='$nm_barang', stok='$stok',
hrg_beli='$hrg_beli', hrg_jual='$hrg_jual'");
return $hasil;
}
...
this is table view which I use to update data using popups
<table class="table table-borderless table-striped table-earning">
<h2>BARANG</h2><br>
<thead>
<tr>
<th>ID BARANG</th>
<th>ID JENIS</th>
<th>NAMA BARANG</th>
<th class="text-right">STOK</th>
<th class="text-right">HARGA BELI</th>
<th class="text-right">HARGA JUAL</th>
<th>ACTION</th>
</tr>
</thead>
<tbody>
<tr>
<?php
foreach($barang as $i): ?>
<td><?=$i->id_barang;?></td>
<td><?=$i->id_jenis;?></td>
<td><?=$i->nm_barang;?></td>
<td><?=$i->stok;?></td>
<td><?=$i->hrg_beli;?></td>
<td><?=$i->hrg_jual;?></td>
<td style="text-align: center">
<a data-toggle="modal" data-target="#modal_edit<?= $i->id_barang;?>" class="btn btn-success">
<i class="fa fa-pencil" color="white"></i>Ubah
</a>
</td>
</tr>
</tbody>
<?php endforeach ?>
</table>
and this is the popups code
(sorry i cant write it one the page :(( )here is the pict
Opening
Closing
just in case the source code
( https://drive.google.com/open?id=1LbKScF65ej2kT0iQfhU2egBwAGWGA7Ee )

Answer 1

You have used redirect('cukl', 'refresh'); to redirect
Redirect goes in ways :-
redirect('control_name/method_name','refresh')

Answer 2

Your Code is right,but I think there is problem with routing.
You can try it by 301 redirect
redirect('/cukl', 'location', 301);
if still problem not solved please provide .htaccess and config/routes.php here.