如何在 codeIgniter 框架中上传文件时显示加载.gif

这是我在控制器中的函数。我没有使用 ajax 函数上传数据，而是提交表单，我是 PHP 语言的新手。我想显示一个加载 gif，直到上传完成。我尝试搜索，但没有找到这个框架的答案。

try {
            $config['upload_path'] = './uploads/';
            $config['allowed_types'] = '*';
            $this->load->helper('file');
            $this->load->library('upload', $config);
            if (!$this->upload->do_upload()) {
                $this->session->set_flashdata('import_attendance', '<br><span style="font-size: 13px;background-color: #FFFFFF;color:#ff0000;border:solid 1px #ff99cc;padding:2px;border-radius: 5px 5px 5px 5px">No file is Selected</span>');
                redirect('import/drawIndexAttendanceImport');
            } else {
                $upfile = array('upload_data' => $this->upload->data());
                $this->load->library('/lib/PHPExcel.php');
                $inputFileName = $upfile['upload_data']['full_path'];  
                $this->load->model('import/import_model');  
$result = $this->import_model->importAttendance($inputFileName);
                if ($result == true) {
                    $this->session->set_flashdata('import_attendance', '<br><span style="font-size: 13px;background-color: #FFFFFF;color:#00cc00;border:solid 1px #00cc00;padding:2px;border-radius: 5px 5px 5px 5px">Succussfully Uploaded </span>');
                    redirect('import/drawIndexAttendanceImport');
                } else {
                    $this->session->set_flashdata('import_attendance', '<br><span style="font-size: 13px;background-color: #FFFFFF;color:#ff0000;border:solid 1px #ff99cc;padding:2px;border-radius: 5px 5px 5px 5px">Upload Error</span>');
                    redirect('import/drawIndexAttendanceImport');
                }
            }
            $this->template->draw('import/drawAttendanceImport', $data);
        } catch (Exception $exc) {
        }
    }