//script view checkout.php
<div class="row">
    <div class="col m10 s12 offset-m1">
<h4 style="color: #939393"><i class="fa fa-shopping-bag"></i> Checkout </h4>
<hr />
<br />
<form action="" method="post">
    <div class="col m10 s12">
        <div class="row">
            <div class="col m8 s12">
                <label>Provinsi</label>
                <select class="browser-default" name="prov" id="prov">
                    <option value="" disabled selected>--Pilih Provinsi --</option>
                    <?php $this->load->view('prov'); ?>
                </select>
            </div>
        </div>
        <div class="row">
            <div class="col m8 s12">
                <label>Pilih kota / kabupaten</label>
                <select class="browser-default" name="kota" id="kota">
                    <option value="" disabled selected>--Kota / kabupaten --</option>
                </select>
            </div>
        </div>

        <div class="row">
            <div class="input-field col m8 s12">
                <input id="alamat" type="text" class="validate" name="alamat" value="">
                <label for="alamat">Alamat</label>
            </div>
        </div>
            <div class="input-field col m4 s12">
                <input id="kd_pos" type="number" class="validate" name="kd_pos" value="">
                <label for="kd_pos">Kode Pos</label>
            </div>

        <div class="row">
            <div class="col m8 s12">
                <label>Pilih kurir</label>
                <select class="browser-default" name="kurir" id="kurir">
                    <option>JNE</option>
                    <option>POS</option>
                </select>
            </div>
        </div>
        <div class="row">
            <div class="col m8 s12">
                <label>Pilih layanan</label>
                <select class="browser-default" name="layanan" id="layanan">
                    <option value="" disabled selected>Pilih Layanan</option>
                </select>
            </div>
        </div>
            <div class="col m4 s12">
                <label>Ongkos Kirim</label>
                <input type="number" name="ongkir" value="0" id="ongkir">
            </div>

        <div class="row">
            <div class="input-field col m4 s12 offset-m8">
                <input type="number" name="total" value="<?= $this->cart->total(); ?>" id="total">
                <label>Total Biaya</label>
            </div>
        </div>

        <div class="row right">
            <button type="submit" name="submit" value="Submit" class="btn blue waves-effect waves-light">Submit <i class="fa fa-paper-plane"></i></button>
            <button type="button" onclick="window.history.go(-1)" class="btn red waves-effect waves-light">Kembali</button>
        </div>
    </div>
</form>
</div>
</div>

//controller
public function getcost()
    {
        $asal = 305;
        $dest = $this->input->post('dest', TRUE);
        $kurir = $this->input->post('kurir', TRUE);
        $berat = 0;

        foreach ($this->cart->contents() as $key) {
            $berat += ($key['weight'] * $key['qty']);
        }

        $curl = curl_init();

        curl_setopt_array($curl, array(
          CURLOPT_URL => "http://api.rajaongkir.com/starter/cost",
          CURLOPT_RETURNTRANSFER => true,
          CURLOPT_ENCODING => "",
          CURLOPT_MAXREDIRS => 10,
          CURLOPT_TIMEOUT => 30,
          CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
          CURLOPT_CUSTOMREQUEST => "POST",
          CURLOPT_POSTFIELDS => "origin=$asal&destination=$dest&weight=$berat&courier=$kurir",
          CURLOPT_HTTPHEADER => array(
            "content-type: application/x-www-form-urlencoded",
            "key: c1d917a4832808c1778afa2b35f686f9"
          ),
        ));

        $response = curl_exec($curl);
        $err = curl_error($curl);

        curl_close($curl);

        if ($err) {
          echo "cURL Error #:" . $err;
        } else {
          $data = json_decode($response, TRUE);

          echo '<option value="" selected disabled>Layanan yang tersedia</option>';

          for ($i=0; $i < count($data['rajaongkir']['results']); $i++) {

                for ($l=0; $l < count($data['rajaongkir']['results'][$i]['costs']); $l++) {

                    echo '<option value="'.$data['rajaongkir']['results'][$i]['costs'][$l]['cost'][0]['value'].','.$data['rajaongkir']['results'][$i]['costs'][$l]['service'].'('.$data['rajaongkir']['results'][$i]['costs'][$l]['description'].')">';
                    echo $data['rajaongkir']['results'][$i]['costs'][$l]['service'].'('.$data['rajaongkir']['results'][$i]['costs'][$l]['description'].')</option>';

                }

          }
        }
    }

//script ajax pada index
        $('#kota').change(function() {
                var kota = $('#kota').val();
                var dest = kota.split(',');
                var kurir = $('#kurir').val()

                $.ajax({
                  url: "<?=base_url();?>checkout/getcost",
                  method: "POST",
                  data: { dest : dest[0], kurir : kurir},
                  success: function(obj) {
                    $('#layanan').html(obj);
                  }

                });
              });

              $('#kurir').change(function() {
                var kota = $('#kota').val();
                var dest = kota.split(',');
                var kurir = $('#kurir').val()

                $.ajax({
                  url: "<?=base_url();?>checkout/getcost",
                  method: "POST",
                  data: { dest : dest[0], kurir : kurir},
                  success: function(obj) {
                    $('#layanan').html(obj);
                  }

                });
              });