tolong master. saya mengalami kendala.

ingin saya jika tidak ada file img tidak bisa di save ke database. jika file img ada tapi tidak ada file pdf tetap bisa di save di sourcecode saya di bawah. sudah bisa menjalankan itu. tapi waktu file img ada dan file pdf ada. muncul peringatan file tipe tidak di izinkan. setelah saya cek, upload file pdf yg error. kira2 error dmn ya? public function tambah_acara() { $data['menu'] = 'acara'; $data['title'] = 'Tambah Berita'; $data['user'] = $this->db->get_where('karyawan', ['email' => $this->session->userdata('email')])->row_array(); $data['web'] = $this->db->get('website')->row_array(); $data['acara'] = $this->db->get('acara')->result_array(); $data['kategori'] = $this->db->get('kategori_acara')->result_array(); date_default_timezone_set('Asia/Jakarta'); $this->form_validation->set_rules('judul', 'Judul', 'required|is_unique[acara.judul]',['is_unique' => 'Judul ini sudah Ada!']); $this->form_validation->set_rules('kategori', 'Kategori', 'required',['required' => 'Kategori belum di isi.!']); $this->form_validation->set_rules('isi', 'Isi', 'required',['required' => 'Bidang belum di isi.!']); if ($this->form_validation->run() == false) { $this->load->view('template/header', $data); if ($data['user']['role_id'] !== '1') { $this->load->view('template/sidebar_karyawan', $data); }else{ $this->load->view('template/sidebar_admin', $data); } $this->load->view('template/topbar_admin', $data); $this->load->view('admin/website/acara/tambah_acara', $data); $this->load->view('template/footer_admin'); } else { $judul = $this->input->post('judul'); $slug = url_title($judul,"underscore",true); $pdf = $_FILES['pdf']; $img = $_FILES['gambar']; $tempat = "SMK"; $jam = date('h:i:s a'); $tgl = date('Y-m-d');

         if ($img['name'] == '') {
            $this->session->set_flashdata('message', '<div class="alert alert-danger alert-dismissible fade show" role="alert">
            Gambar Tidak Boleh Kosong :)
            <button type="button" class="close" data-dismiss="alert" aria-label="Close">
            <span aria-hidden="true">×</span>
          </button>
          </div>');
            redirect('admin/tambah_acara');
         }else{
            $config['upload_path'] = './assets/img/blog/';
            $config['allowed_types'] = 'jpg|png|jpeg';
            $config['max_size']  = '8048';
            $config['remove_space'] = TRUE;
            $this->load->library('upload', $config); // Load konfigurasi uploadnya

            if (!$this->upload->do_upload('gambar')) {
                 $this->session->set_flashdata('message', $this->upload->display_errors());
                redirect('admin/tambah_acara');
            }else{
                $gambar = $this->upload->data('file_name');
                    if($pdf['name']==''){
                            $data = [
                                    'judul' => $judul,
                                    'slug' => $slug,
                                    'deskripsi'   => $this->input->post('isi'),
                                    'id_kat' => $this->input->post('kategori'),
                                    'img' => $gambar,
                                    'tempat' => $tempat,
                                    'tgl' => $tgl,
                                    'jam' => $jam,
                                    'id_peng' => $data['user']['id']
                                ];
                                    $this->db->insert('acara', $data);
                                    $this->session->set_flashdata('message', '<div class="alert alert-success alert-dismissible fade show" role="alert">
                                    Data Berita<strong>' . $judul . '</strong> berhasil ditambahkan :)
                                    <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                                    <span aria-hidden="true">×</span>
                                </button>
                                </div>');
                                    redirect('admin/acara');
                    }else{
                            $config1['upload_path'] = './assets/pdf/';
                            $config1['allowed_types'] = 'pdf';
                            $config1['max_size']  = '20048';
                            $config1['remove_space'] = TRUE;
                            $this->load->library('upload', $config1);
                            if (!$this->upload->do_upload('pdf')) {
                                $this->session->set_flashdata('message', $this->upload->display_errors());
                                redirect('admin/tambah_acara');
                            }else{ 
                                $gambar = $this->upload->data('file_name');
                                $pdf = $this->upload->data('file_name');
                                $data = [
                                    'judul' => $judul,
                                    'slug' => $slug,
                                    'deskripsi'   => $this->input->post('isi'),
                                    'id_kat' => $this->input->post('kategori'),
                                    'img' => $gambar,
                                    'pdf' => $pdf,
                                    'tempat' => $tempat,
                                    'tgl' => $tgl,
                                    'jam' => $jam,
                                    'id_peng' => $data['user']['id']
                                ];
                                    $this->db->insert('acara', $data);
                                    $this->session->set_flashdata('message', '<div class="alert alert-success alert-dismissible fade show" role="alert">
                                    Data Berita<strong>' . $judul . '</strong> berhasil ditambahkan :)
                                    <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                                    <span aria-hidden="true">×</span>
                                    </button>
                                    </div>');
                                    redirect('admin/acara');
                    }
                }
            }
        }
    }
}