PHP钩子机制原理及详解

<?php
class Blog extends Controller{
 
 public function add(){
 
 //some code
 $res = $data;
 
 return $res;
 }
}
$obj = new Blog();
Log::write($_REQUEST);
$res = $obj->add();
Log::write(json_encode($res));

<?php
class Blog extends Controller{
 
 public function add(){
 
 //some code
 $res = $data;
 
 return $res;
 }
}
$obj = new Blog();
OnBeforeRunActionCallback($_REQUEST);
$obj->add();
OnAfterRunActionCallback($res);
function OnBeforeRunActionCallback($param){
 Log::write($param);
 FilterParams($param);
}
function OnAfterRunActionCallback($res){
 Log::write(json_encode($res));
}

$_listeners = array(
 'OnBeforeRunAction' => array(
 'callback1',
 'callback2',
 'callback3',
 ),
);
//提前注册插件到钩子
add_hook('OnBeforeRunAction', 'callback4');
//特定地方执行钩子
trigger_hook('OnBeforeRunAction');

function trigger_hook($hook, $data=''){
 //查看要实现的钩子，是否在监听数组之中
 if (isset($this->_listeners[$hook]) && is_array($this->_listeners[$hook]) && count($this->_listeners[$hook]) > 0)
 {
 // 循环调用开始
 foreach ($this->_listeners[$hook] as $listener)
 {
 if(is_callable()){
 call_user_func($listener, $data);
 }elseif(is_array($listener)){
 // 取出插件对象的引用和方法
 $class =& $listener[0];
 $method = $listener[1];
 if(method_exists($class,$method))
 {
 // 动态调用插件的方法
 $class->$method($data);
 }
 }
 }
 }
}

class Hook
{
 //action hooks array 
 private static $actions = array();
 /**
 * ads a function to an action hook
 * @param $hook
 * @param $function
 */
 public static function add_action($hook,$function)
 { 
 $hook=mb_strtolower($hook,CHARSET);
 // create an array of function handlers if it doesn't already exist
 if(!self::exists_action($hook))
 {
 self::$actions[$hook] = array();
 }
 // append the current function to the list of function handlers
 if (is_callable($function))
 {
 self::$actions[$hook][] = $function;
 return TRUE;
 }
 return FALSE ;
 }
 /**
 * executes the functions for the given hook
 * @param string $hook
 * @param array $params
 * @return boolean true if a hook was setted
 */
 public static function do_action($hook,$params=NULL)
 {
 $hook=mb_strtolower($hook,CHARSET);
 if(isset(self::$actions[$hook]))
 {
 // call each function handler associated with this hook
 foreach(self::$actions[$hook] as $function)
 {
 if (is_array($params))
 {
 call_user_func_array($function,$params);
 }
 else
 {
 call_user_func($function);
 }
 //cant return anything since we are in a loop! dude!
 }
 return TRUE;
 }
 return FALSE;
 }
 /**
 * gets the functions for the given hook
 * @param string $hook
 * @return mixed
 */
 public static function get_action($hook)
 {
 $hook=mb_strtolower($hook,CHARSET);
 return (isset(self::$actions[$hook]))? self::$actions[$hook]:FALSE;
 }
 /**
 * check exists the functions for the given hook
 * @param string $hook
 * @return boolean
 */
 public static function exists_action($hook)
 {
 $hook=mb_strtolower($hook,CHARSET);
 return (isset(self::$actions[$hook]))? TRUE:FALSE;
 }
}
 
 /**
 * Hooks Shortcuts not in class
 */
 function add_action($hook,$function)
 {
 return Hook::add_action($hook,$function);
 }
 
 function do_action($hook)
 {
 return Hook::do_action($hook);
 }

//添加钩子
Hook::add_action('unique_name_hook','some_class::hook_test');
//或使用快捷函数添加钩子:
add_action('unique_name_hook','other_class::hello');
add_action('unique_name_hook','some_public_function');
//执行钩子
do_action('unique_name_hook');//也可以使用 Hook::do_action();

<?php
/**
 * @file plugin.php
 * @brief 插件核心类
 * @note 观察者模式，注册事件，触发事件
 */
class plugin extends IInterceptorBase
{
 //默认开启的插件列表
 private static $defaultList = array("_verification","_goodsCategoryWidget","_authorization","_userInfo","_initData");
 //已经注册监听
 private static $_listen = array();
 //加载插件
 public static function init()
 {
 $pluginDB = new IModel('plugin');
 $pluginList = $pluginDB->query("is_open = 1","class_name","sort asc");
 //加载默认插件
 foreach(self::$defaultList as $val)
 {
 $pluginList[]= array('class_name' => $val);
 }
 foreach($pluginList as $key => $val)
 {
 $className = $val['class_name'];
 $classFile = self::path().$className."/".$className.".php";
 if(is_file($classFile))
 {
 include_once($classFile);
 $pluginObj = new $className();
 $pluginObj->reg();
 }
 }
 }
 /**
 * @brief 注册事件
 * @param string $event 事件
 * @param object ro function $classObj 类实例 或者 匿名函数
 * @param string $method 方法名字
 */
 public static function reg($event,$classObj,$method = "")
 {
 if(!isset(self::$_listen[$event]))
 {
 self::$_listen[$event] = array();
 }
 self::$_listen[$event][] = array($classObj,$method);
 }
 /**
 * @brief 显示已注册事件
 * @param string $event 事件名称
 * @return array
 */
 public static function get($event = '')
 {
 if($event)
 {
 if( isset(self::$_listen[$event]) )
 {
 return self::$_listen[$event];
 }
 return null;
 }
 return self::$_listen;
 }
 /**
 * @brief 触发事件
 * @param string $event 事件
 * @param mixed $data 数据
 * @notice 可以调用匿名函数和方法
 */
 public static function trigger($event,$data = null)
 {
 $result = array();
 if(isset(self::$_listen[$event]))
 {
 foreach(self::$_listen[$event] as $key => $val)
 {
 list($pluginObj,$pluginMethod) = $val;
 $result[$key] = is_callable($pluginObj) ? call_user_func($pluginObj,$data):call_user_func(array($pluginObj,$pluginMethod),$data);
 }
 }
 return isset($result[1]) ? $result : current($result);
 }
 /**
 * @brief 插件物理路径
 * @return string 路径字符串
 */
 public static function path()
 {
 return IWeb::$app->getBasePath()."plugins/";
 }
 /**
 * @brief 插件WEB路径
 * @return string 路径字符串
 */
 public static function webPath()
 {
 return IUrl::creatUrl('')."plugins/";
 }
 /**
 * @brief 获取全部插件
 * @param string $name 插件名字，如果为空则获取全部插件信息
 * @return array 插件信息 array(
 "name" => 插件名字,
 "description" => 插件描述,
 "explain" => 使用说明,
 "class_name" => 插件ID,
 "is_open" => 是否开启,
 "is_install" => 是否安装,
 "config_name" => 默认插件参数结构,
 "config_param"=> 已经保存的插件参数,
 "sort" => 排序,
 )
 */
 public static function getItems($name = '')
 {
 $result = array();
 $dirRes = opendir(self::path());
 //遍历目录读取配置文件
 $pluginDB = new IModel('plugin');
 while($dir = readdir($dirRes))
 {
 if($dir[0] == "." || $dir[0] == "_")
 {
 continue;
 }
 if($name && $result)
 {
 break;
 }
 if($name && $dir != $name)
 {
 continue;
 }
 $pluginIndex = self::path().$dir."/".$dir.".php";
 if(is_file($pluginIndex))
 {
 include_once($pluginIndex);
 if(get_parent_class($dir) == "pluginBase")
 {
 $class_name = $dir;
 $pluginRow = $pluginDB->getObj('class_name = "'.$class_name.'"');
 $is_open = $pluginRow ? $pluginRow['is_open'] : 0;
 $is_install = $pluginRow ? 1 : 0;
 $sort = $pluginRow ? $pluginRow['sort'] : 99;
 $config_param = array();
 if($pluginRow && $pluginRow['config_param'])
 {
 $config_param = JSON::decode($pluginRow['config_param']);
 }
 $result[$dir] = array(
 "name" => $class_name::name(),
 "description" => $class_name::description(),
 "explain" => $class_name::explain(),
 "class_name" => $class_name,
 "is_open" => $is_open,
 "is_install" => $is_install,
 "config_name" => $class_name::configName(),
 "config_param"=> $config_param,
 "sort" => $sort,
 );
 }
 }
 }
 if(!$name)
 {
 return $result;
 }
 return isset($result[$name]) ? $result[$name] : array();
 }
 /**
 * @brief 系统内置的所有事件触发
 */
 public static function onCreateApp(){plugin::init();plugin::trigger("onCreateApp");}
 public static function onFinishApp(){plugin::trigger("onFinishApp");}
 public static function onBeforeCreateController($ctrlId){plugin::trigger("onBeforeCreateController",$ctrlId);plugin::trigger("onBeforeCreateController@".$ctrlId);}
 public static function onCreateController($ctrlObj){plugin::trigger("onCreateController");plugin::trigger("onCreateController@".$ctrlObj->getId());}
 public static function onFinishController($ctrlObj){plugin::trigger("onFinishController");plugin::trigger("onFinishController@".$ctrlObj->getId());}
 public static function onBeforeCreateAction($ctrlObj,$actionId){plugin::trigger("onBeforeCreateAction",$actionId);plugin::trigger("onBeforeCreateAction@".$ctrlObj->getId());plugin::trigger("onBeforeCreateAction@".$ctrlObj->getId()."@".$actionId);}
 public static function onCreateAction($ctrlObj,$actionObj){plugin::trigger("onCreateAction");plugin::trigger("onCreateAction@".$ctrlObj->getId());plugin::trigger("onCreateAction@".$ctrlObj->getId()."@".$actionObj->getId());}
 public static function onFinishAction($ctrlObj,$actionObj){plugin::trigger("onFinishAction");plugin::trigger("onFinishAction@".$ctrlObj->getId());plugin::trigger("onFinishAction@".$ctrlObj->getId()."@".$actionObj->getId());}
 public static function onCreateView($ctrlObj,$actionObj){plugin::trigger("onCreateView");plugin::trigger("onCreateView@".$ctrlObj->getId());plugin::trigger("onCreateView@".$ctrlObj->getId()."@".$actionObj->getId());}
 public static function onFinishView($ctrlObj,$actionObj){plugin::trigger("onFinishView");plugin::trigger("onFinishView@".$ctrlObj->getId());plugin::trigger("onFinishView@".$ctrlObj->getId()."@".$actionObj->getId());}
 public static function onPhpShutDown(){plugin::trigger("onPhpShutDown");}
}
/**
 * @brief 插件基类，所有插件必须继承此类
 * @notice 必须实现3个抽象方法： reg(),name(),description()
 */
abstract class pluginBase extends IInterceptorBase
{
 //错误信息
 protected $error = array();
 //注册事件接口，内部通过调用payment::reg(事件,对象实例,方法);
 public function reg(){}
 /**
 * @brief 默认插件参数信息，写入到plugin表config_param字段
 * @return array("字段名" => array(
 "name" => "文字显示",
 "type" => "数据类型【text,radio,checkbox,select】",
 "pattern" => "数据校验【int,float,date,datetime,require,正则表达式】",
 "value" => "1,数组：枚举数据【radio,checkbox,select】的预设值,array(名字=>数据); 2,字符串：【text】默认数据",
 ))
 */
 public static function configName()
 {
 return array();
 }
 /**
 * @brief 插件安装
 * @return boolean
 */
 public static function install()
 {
 return true;
 }
 /**
 * @brief 插件卸载
 * @return boolean
 */
 public static function uninstall()
 {
 return true;
 }
 /**
 * @brief 插件名字
 * @return string
 */
 public static function name()
 {
 return "插件名称";
 }
 /**
 * @brief 插件功能描述
 * @return string
 */
 public static function description()
 {
 return "插件描述";
 }
 /**
 * @brief 插件使用说明
 * @return string
 */
 public static function explain()
 {
 return "";
 }
 /**
 * @brief 获取DB中录入的配置参数
 * @return array
 */
 public function config()
 {
 $className= get_class($this);
 $pluginDB = new IModel('plugin');
 $dataRow = $pluginDB->getObj('class_name = "'.$className.'"');
 if($dataRow && $dataRow['config_param'])
 {
 return JSON::decode($dataRow['config_param']);
 }
 return array();
 }
 /**
 * @brief 返回错误信息
 * @return array
 */
 public function getError()
 {
 return $this->error ? join("
",$this->error) : "";
 }
 /**
 * @brief 写入错误信息
 * @return array
 */
 public function setError($error)
 {
 $this->error[] = $error;
 }
 /**
 * @brief 插件视图渲染有布局
 * @param string $view 视图名字
 * @param array $data 视图里面的数据
 */
 public function redirect($view,$data = array())
 {
 if($data === true)
 {
 $this->controller()->redirect($view);
 }
 else
 {
 $__className = get_class($this);
 $__pluginViewPath = plugin::path().$__className."/".$view;
 $result = self::controller()->render($__pluginViewPath,$data);
 if($result === false)
 {
 IError::show($__className."/".$view."插件视图不存在");
 }
 }
 }
 /**
 * @brief 插件视图渲染去掉布局
 * @param string $view 视图名字
 * @param array $data 视图里面的数据
 */
 public function view($view,$data = array())
 {
 self::controller()->layout = "";
 $this->redirect($view,$data);
 }
 /**
 * @brief 插件物理目录
 * @param string 插件路径地址
 */
 public function path()
 {
 return plugin::path().get_class($this)."/";
 }
 /**
 * @brief 插件WEB目录
 * @param string 插件路径地址
 */
 public function webPath()
 {
 return plugin::webPath().get_class($this)."/";
 }
}