Upload Banyak Gambar, Tampilkan Preview dan Simpan ke Databa

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CONTROLLER
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public function tambah_proses()
{
    $this->load->library('upload');
    $dataInfo = array();
    $files = $_FILES;
    $cpt = count($_FILES['userfile']['name']);
    for($i=0; $i<$cpt; $i++)
    {
        $_FILES['userfile']['name']= $files['userfile']['name'][$i];
        $_FILES['userfile']['type']= $files['userfile']['type'][$i];
        $_FILES['userfile']['tmp_name']= $files['userfile']['tmp_name'][$i];
        $_FILES['userfile']['error']= $files['userfile']['error'][$i];
        $_FILES['userfile']['size']= $files['userfile']['size'][$i];

        $this->upload->initialize($this->set_upload_options());
        $this->upload->do_upload();
        $dataInfo[] = $this->upload->data();
    }

    $data = array(
        'judul_produk' => $this->input->post('judul_produk'),
        'userfile' => $dataInfo[0]['file_name'],
        'userfile2' => $dataInfo[1]['file_name'],
        'userfile3' => $dataInfo[2]['file_name'],
     );

     $this->Produk_model->insert($data);
}

private function set_upload_options()
{
    $config = array();
    $config['upload_path'] = 'images/';
    $config['allowed_types']    = 'jpg|jpeg|png|gif';
    $config['max_size']         = '2048'; // 2 MB

    return $config;
}

----------------------------------------------------------------------------
MODEL
----------------------------------------------------------------------------
function insert($data)
{
  $this->db->insert('namatabel', $data);
}

----------------------------------------------------------------------------
VIEW
----------------------------------------------------------------------------
<?php echo form_open_multipart(site_url('tambah_proses'));?>
<div class="form-group"><label>Gambar</label>
  <input type="file" name="userfile[]" multiple>
</div>
<?php echo form_close() ?>