实现权限访问控制功能

//在基类控制器中实现访问控制
<?php
namespace app\admins\controller;
use think\Controller;
use util\SysDb;
class Base extends Controller
{
  public function __construct()
  {
    parent::__construct();
    $this->_admin = session('admin');

    if(empty($this->_admin)){
      $this->redirect('Account/login');
    }
    $this->db = new SysDb;

    $role = $this->db->table('roles')->where(['gid'=>$this->_admin['gid']])->item();

    if($this->_admin['username']!='admin' && empty($role)){
        session('admin',null);
        $this->errorInfo('对不起，您还没有分配角色，无法访问后台');
    }

    $controller = request()->controller();
    $method = request()->action();
    $res = $this->db->table('menus')->where(['controller'=>$controller,'method'=>$method])->item();
    if(!$res){
        $this->errorInfo('对不起，您访问的菜单不存在');
    }
    if($res['status']){
        $this->errorInfo('对不起，您访问的菜单已禁用');
    }
    if($this->_admin['username']!='admin'){
        $rights = !empty($role['rights'])?json_decode($role['rights'],true):[];
        if(!in_array($res['menu_id'],$rights)){
            $this->errorInfo('对不起，您没有权限访问该菜单');
        }
    }
  }
  private function errorInfo($msg)
  {
      if(request()->isAjax()){
          exit(json_encode(['code'=>1,'msg'=>$msg]));
      }else{
          exit($msg);
      }
  }
}
 ?>