codeigniter框架扩展核心类---实现前台后台视图的分离

1. 扩展核心类，主要作用就是扩展系统现在的功能。

为前台增加独立的视图文件夹：

a. 自定义路径常量：在application ->config/ constants.php中增加

/*my constant*/

define('THEMEES_DIR','themes/');

　　b. 在application文件夹的core中自定义MY_Loader.php

/*
 分析核心类中自动加载的功能的实现方式
*/
<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class MY_Loader extends CI_Loader
{
    
    protected $_theme = 'default/';
    
    public function switch_themes_on()
    {
        $this->_ci_view_paths = array(FCPATH.THEMEES_DIR.$this->_theme => TRUE);
        var_dump($this->_ci_view_paths);
    }
    public function switch_themes_off()
    {
        
    }
}

　　c. 自定义控制器：实现前台后台视图分离

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Home_Controller extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->load->switch_themes_on();        
    }
}

class Admin_Controller extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->load->switch_themes_off();
    }
}

d. 定义控制器类，继承相应的Home_controller,admin_controller控制器。在admin子控制器文件夹中，

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
    
    class Hello extends Admin_Controller {
        function index()
        {

            $data['title'] = "this is title.";
            $data['content'] = "this is content.";
            $this->load->view('hello.php',$data);
        }
    }

定义相应的视图文件夹及文件view /admin /hello.php

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>admin
<?php echo $content; ?>
</html>

前台独立文件夹 /themes/default

控制器themes.php

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
    
    class Themes extends Home_Controller {
        function index()
        {

            $data['title'] = "this is title.";
            $data['content'] = "this is content.";
            $this->load->view('themes.php',$data);
        }
    }

注：系统仅支持一层子文件夹，因此需要扩展核心类，实现多层视图文件，及放置到其它独立文件夹中。