PHP实战：CI框架源码解读之利用Hook.php文件完成功能扩展的方法

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class CI_Hooks {
 var $enabled = FALSE; 
 //开启hook的标志,默认是关闭的.APPPATH/config/config.php中的配置也是默认关闭的,如果想使用hook,要在config.php中开启.
 var $hooks = array();
 //在_initialize()函数初始化的过程中将APPPATH/config/hook.php中定义的hook数组,引用到$this->hooks;
 var $in_progress  = FALSE;
 //当一个hook执行的时候,会给标记 $in_process = TRUE ,是为了防止同一个hook被同时调用.
 function __construct()
 {
  $this->_initialize();
  log_message('debug', "Hooks Class Initialized");
 }
 function _initialize()
 {
  //初始化hook
  //判断config.php中是否开启hook
  //include(hook.php),将文件里定义的hook数组引用到$this->hooks
  //$this->enable = TRUE 
 }
 function _call_hook($which = '')//pre_system
 {
  //以pre_system挂钩点为例,当调用_call_hook('pre_system')时
  //确保$this->enable = TRUE && 定义了$this->hooks['pre_system']
  //如果是二维数组就遍历,依次_run_hook($this->hooks['pre_system'][$val])
  //如果是一维数组,那么直接_run_hook($this->hooks['pre_system'])
 }
 function _run_hook($data) //$data 是传递过来的hook数组
 {
  //$data 就是我们在APPPATH/config/hook.php 定义的hook数组
  //$hook['pre_controller'] = array(
  // 'class'  => 'MyClass',
  // 'function' => 'Myfunction',
  // 'filename' => 'Myclass.php',
  // 'filepath' => 'hooks',
  // 'params'  => array('beer', 'wine', 'snacks')
  // );
  //取出data里面的数据,加载
  APPPATH.$data['filepath'].$data['filename'];
  //实例化钩子类,调用function.应用到示例中就是
  $this->in_process = TRUE;
  $Hook = new MyClass();
  $Hook->Myfunction($params);
  $this->in_process = FALSE;
  }
}
?>