Upload PDF

$jam                     = time();
        $propose_id              = $this->input->post('id', 'true');
        $username                = $this->input->post('username', 'true');
        $config['file_name']     = 'Proposal_' . $propose_id . '_' . $username . '_' . $jam . '.pdf';
        $config['upload_path']   = './upload_file/proposal/';
        $config['allowed_types'] = 'pdf';
        $config['overwrite']     = true;
        $config['max_size']      = 0;
        $this->load->library('upload');
        $this->upload->initialize($config);

        if (!$this->upload->do_upload('file_pdf')) {
            $response['status'] = 'error';
        } else {
            $this->hasil_m->upload_data();
            $response['status'] = 'success';
        }

        echo json_encode($response);