saya debug kategori

<nav class="navbar navbar-default">
  <div class="container-fluid">
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <?=anchor(base_url(),'Sewa Alat Catering Oval', ['class'=>'navbar-brand'])?>
    </div>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">

      <ul class="nav navbar-nav navbar-left">
        <li><?php echo anchor(base_url(),'Home'); ?></li>
      <?php
        if(isset($kategori)){ ?>
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Kategori <span class="caret"></span></a>
          <ul class="dropdown-menu">
<?php
        foreach($kategori as $kat){?>
            <li><a href="#"><?=isset($kat->nama_kategori)?$kat->nama_kategori:json_encode($kat);?></a></li>
<?php   } ?>
          </ul>
        </li>

<?php
        }
        else{
            echo '<!-- no kategori -->';
        }
?>
        <?php if($this->session->userdata('username')) {?>
        <li><?php echo anchor('customer/shopping_history','Konfirmasi Pembayaran'); ?></li>
        <?php }else{} ?>

      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li>
            <?php
                $text_cart_url  = '<span class="glyphicon glyphicon-shopping-cart" aria-hidden="true"></span>';
                $text_cart_url .= ' Keranjang : '. $this->cart->total_items().' Barang';
            ?>
            <?=anchor('welcome/cart', $text_cart_url) ?>
        </li>
            <?php if($this->session->userdata('username')) {?>
                <li><div style="line-height:50px;"><?=$this->session->userdata('username')?></div></li>
                <li><?php echo anchor('logout','Logout'); ?></li>
            <?php }else{ ?>
                <li><?php echo anchor('login','Login'); ?></li>
            <?php }?>
      </ul>

    </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>
if(isset($kategori)){ echo '<pre>'.print_r($kategori,1).'</pre>'; }else{ echo 'tidak ada variabel kategori dikirim? '; var_dump($this->model_kategori->all()); }