How to implement PHP's universal controller

<?php
namespace 目录\Controller;
class TypeController extends Controller
{
  public function add()
  {
    if(IS_POST)
    {
      $model = D(&#39;Type&#39;);
      if($model->create())
      {
        if($model->add())
        {
          $this->success(&#39;添加成功！&#39;, U(&#39;lst&#39;));
          exit;
        }
        else
        {
          $sql = $model->getLastSql();
          $this->error(&#39;插入数据库失败！.<hr />SQL:&#39;.$sql);
        }
      }
      else
      {
        $error = $model->getError();
        $this->error($error);
      }
    }
    $this->display();
  }
  public function lst()
  {
    $model = D(&#39;Type&#39;);
    $data = $model->search();
    $this->assign($data);
    $this->display();
  }
  public function save($id)
  {
    $model = D(&#39;Type&#39;);
    if(IS_POST)
    {
      if($model->create())
      {
        if($model->save() !== FALSE)
        {
          $this->success(&#39;修改成功！&#39;, U(&#39;lst&#39;));
          exit;
        }
        else
        {
          $sql = $model->getLastSql();
          $this->error(&#39;修改数据库失败！.<hr />SQL:&#39;.$sql);
        }
      }
      else
      {
        $error = $model->getError();
        $this->error($error);
      }
    }
    $data = $model->find($id);
    $this->assign(&#39;data&#39;, $data);
    $this->display();
  }
  public function del($id)
  {
    $model = D(&#39;Type&#39;);
    $model->delete($id);
    $this->success(&#39;操作成功！&#39;, U(&#39;lst&#39;));
  }
  public function bdel()
  {
    $delid = I(&#39;post.delid&#39;);
    if($delid)
    {
      $delid = implode(&#39;,&#39;, $delid);
      $model = D(&#39;Type&#39;);
      $model->delete($delid);
    }
    else
      $this->error(&#39;请选择要删除的记录!&#39;);
    $this->success(&#39;操作成功！&#39;, U(&#39;lst&#39;));
  }
}