简介
PHP Reflection API是PHP5才有的新功能，它是用来导出或提取出关于类、方法、属性、参数等的详细信息，包括注释。
class Reflection { } interface Reflector { }class ReflectionException extends Exception { }class ReflectionFunction implements Reflector { }class ReflectionParameter implements Reflector { }class ReflectionMethod extends ReflectionFunction { }class ReflectionClass implements Reflector { }class ReflectionObject extends ReflectionClass { }class ReflectionProperty implements Reflector { }class ReflectionExtension implements Reflector { } 用得比较多的就只有两个ReflectionClass与ReflectionObject，两个的用法都一样，只是前者针对类，后者针对对象，后者是继承前者的类；然后其中又有一些属性或方法能返回对应的Reflection对象（ReflectionProperty以及ReflectionMethod）
ReflectionClass
具体参考手册：http://php.net/manual/zh/clas...
通过ReflectionClass，我们可以得到Person类的以下信息：
- 常量 Contants
- 属性 Property Names
- 方法 Method Names
- 静态属性 Static Properties
- 命名空间 Namespace
- Person类是否为final或者abstract
<?phpnamespace app;class Person{ /** * For the sake of demonstration, we"re setting this private */ private $_allowDynamicAttributes = false; /** type=primary_autoincrement */ protected $id = 0; /** type=varchar length=255 null */ protected $name; /** type=text null */ protected $biography; public function getId(){ return $this->id; } public function setId($v){ $this->id = $v; } public function getName(){ return $this->name; } public function setName($v){ $this->name = $v; } public function getBiography(){ return $this->biography; } public function setBiography($v){ $this->biography = $v; }}//传递类名或对象进来$class = new \ReflectionClass('app\Person');//获取属性，不管该属性是否public$properties = $class->getProperties();foreach($properties as $property) { echo $property->getName()."\n";}// 输出:// _allowDynamicAttributes// id// name// biography//默认情况下，ReflectionClass会获取到所有的属性，private 和 protected的也可以。如果只想获取到private属性，就要额外传个参数：/* * ReflectionProperty::IS_STATIC * ReflectionProperty::IS_PUBLIC * ReflectionProperty::IS_PROTECTED * ReflectionProperty::IS_PRIVATE */ //↓↓ 注意一个|组合： 获得IS_PRIVATE或者IS_PROTECTED的属性$private_properties = $class->getProperties(\ReflectionProperty::IS_PRIVATE|\ReflectionProperty::IS_PROTECTED);foreach($private_properties as $property) { //↓↓如果该属性是受保护的属性； if($property->isProtected()) { // ↓↓ 获取注释 $docblock = $property->getDocComment(); preg_match('/ type\=([a-z_]*) /', $property->getDocComment(), $matches); echo $matches[1]."\n"; }}// Output:// primary_autoincrement// varchar// text$data = array("id" => 1, "name" => "Chris", "biography" => "I am am a PHP developer");foreach($data as $key => $value) { if(!$class->hasProperty($key)) { throw new \Exception($key." is not a valid property"); } if(!$class->hasMethod("get".ucfirst($key))) { throw new \Exception($key." is missing a getter"); } if(!$class->hasMethod("set".ucfirst($key))) { throw new \Exception($key." is missing a setter"); } $object = new Person(); // http://php.net/manual/zh/class.reflectionmethod.php // getMethod 获得一个该方法的reflectionmethod对象，然后使用里面的invoke方法； $setter = $class->getMethod("set".ucfirst($key)); $ok = $setter->invoke($object, $value); // Get the setter method and invoke it $getter = $class->getMethod("get".ucfirst($key)); $objValue = $getter->invoke($object); // Now compare if($value == $objValue) { echo "Getter or Setter has modified the data.\n"; } else { echo "Getter and Setter does not modify the data.\n"; }}getMethod and invoke
ReflectionClass::getMethod — 获取一个类方法的 ReflectionMethod(可以理解为获得这个类方法的控制权，不管这个类方法是否是public)。
具体的参考：
- http://php.net/manual/zh/clas...
- http://php.net/manual/zh/refl...
<?phpclass HelloWorld { private function sayHelloTo($name,$arg1,$arg2) { return 'Hello ' . $name.' '.$arg1.' '.$arg2; }}$obj = new HelloWorld();// 第一个参数可以是对象,也可以是类$reflectionMethod = new ReflectionMethod($obj , 'sayHelloTo');if(!$reflectionMethod -> isPublic()){ $reflectionMethod -> setAccessible(true);}/* * public mixed ReflectionMethod::invoke ( object $object [, mixed $parameter [, mixed $... ]] ) * 1. 获得某个类方法的ReflectionMethod * 2. $object 该方法所在的类实例的对象，然后第二参数起对号入座到该方法的每个参数； * 3. 通过invoke就可以执行这个方法了 */echo $reflectionMethod->invoke($obj, 'GangGe','How','are you');//也可以把参数作为数组传进来echo $reflectionMethod -> invokeArgs($obj,array('GangGe','How','are you'));getProperty
获得一个 ReflectionProperty 类实例 (同上，获得该属性的控制权) http://cn2.php.net/manual/zh/...
getValue获取属性值
public mixed ReflectionProperty::getValue ([ object $object ] )如果该获得该实例的类属性不是一个static的属性，就必须传该类的实例
<?phpclass Foo { public static $staticProperty = 'foobar'; public $property = 'barfoo'; protected $privateProperty = 'foofoo';}$reflectionClass = new ReflectionClass('Foo');var_dump($reflectionClass->getProperty('staticProperty')->getValue()); //静态属性可以不加参数var_dump($reflectionClass->getProperty('property')->getValue(new Foo)); //非静态属性必须加传一个类实例$reflectionProperty = $reflectionClass->getProperty('privateProperty'); //受保护的属性就要通过setAccessible获得其权限$reflectionProperty->setAccessible(true);var_dump($reflectionProperty->getValue(new Foo));Example
模拟YII框架中控制器调用方法的实现
<?phpif (PHP_SAPI != 'cli') { exit('Please run it in terminal!');}if ($argc < 3) { exit('At least 2 arguments needed!');} $controller = ucfirst($argv[1]) . 'Controller';$action = 'action' . ucfirst($argv[2]); // 检查类是否存在if (!class_exists($controller)) { exit("Class $controller does not existed!");} // 获取类的反射$reflector = new ReflectionClass($controller);// 检查方法是否存在if (!$reflector->hasMethod($action)) { exit("Method $action does not existed!");} // 取类的构造函数，返回的是ReflectionMethod对象$constructor = $reflector->getConstructor();// 取构造函数的参数，这是一个对象数组$parameters = $constructor->getParameters();// 遍历参数foreach ($parameters as $key => $parameter) { // 获取参数声明的类 $injector = new ReflectionClass($parameter->getClass()->name); // 实例化参数声明类并填入参数列表 $parameters[$key] = $injector->newInstance(); //实例化$parameter->getClass()->name类} // 使用参数列表实例 controller 类$instance = $reflector->newInstanceArgs($parameters);// 执行$instance->$action(); class HelloController{ private $model; public function __construct(TestModel $model) { $this->model = $model; } public function actionWorld() { echo $this->model->property, PHP_EOL; }} class TestModel{ public $property = 'property';}TP框架中实现前后控制器
<?phpclass BlogAction { public function detail() { echo 'detail' . "\r\n"; } public function test($year = 2014, $month = 4, $day = 21) { echo $year . '--' . $month . '--' . $day . "\r\n"; } public function _before_detail() { echo __FUNCTION__ . "\r\n"; } public function _after_detail() { echo __FUNCTION__ . "\r\n"; }}// 执行detail方法$method = new ReflectionMethod('BlogAction', 'detail');$instance = new BlogAction();// 进行权限判断if ($method->isPublic()) { $class = new ReflectionClass('BlogAction'); // 执行前置方法 if ($class->hasMethod('_before_detail')) { $beforeMethod = $class->getMethod('_before_detail'); if ($beforeMethod->isPublic()) { $beforeMethod->invoke($instance); } } $method->invoke(new BlogAction); // 执行后置方法 if ($class->hasMethod('_after_detail')) { $beforeMethod = $class->getMethod('_after_detail'); if ($beforeMethod->isPublic()) { $beforeMethod->invoke($instance); } }}// 执行带参数的方法$method = new ReflectionMethod('BlogAction', 'test');$params = $method->getParameters();foreach ($params as $param) { $paramName = $param->getName(); if (isset($_REQUEST[$paramName])) { $args[] = $_REQUEST[$paramName]; } elseif ($param->isDefaultValueAvailable()) { $args[] = $param->getDefaultValue(); }}if (count($args) == $method->getNumberOfParameters()) { $method->invokeArgs($instance, $args);} else { echo 'parameters is wrong!';}其他参考
/** * 执行App控制器 */public function execApp() { // 创建action控制器实例 $className = MODULE_NAME . 'Controller'; $namespaceClassName = '\\apps\\' . APP_NAME . '\\controller\\' . $className; load_class($namespaceClassName, false); if (!class_exists($namespaceClassName)) { throw new \Exception('Oops! Module not found : ' . $namespaceClassName); } $controller = new $namespaceClassName(); // 获取当前操作名 $action = ACTION_NAME; // 执行当前操作 //call_user_func(array(&$controller, $action)); // 其实吧，用这个函数足够啦！！！ try { $methodInfo = new \ReflectionMethod($namespaceClassName, $action); if ($methodInfo->isPublic() && !$methodInfo->isStatic()) { $methodInfo->invoke($controller); } else { // 操作方法不是public类型，抛出异常 throw new \ReflectionException(); } } catch (\ReflectionException $e) { // 方法调用发生异常后，引导到__call方法处理 $methodInfo = new \ReflectionMethod($namespaceClassName, '__call'); $methodInfo->invokeArgs($controller, array($action, '')); } return;}