yii2源码学习笔记(十六）

Module类的最后代码

     /**
      * Registers sub-modules in the current module.
      * 注册子模块到当前模块
      * Each sub-module should be specified as a name-value pair, where
      * name refers to the ID of the module and value the module or a configuration
      * array that can be used to create the module. In the latter case, [[Yii::createObject()]]
      * will be used to create the module.
      * 子模块以键值对的方式指定，键名为模块ID，键值为模块对象或者用于创建模块对象的配置数组
      * If a new sub-module has the same ID as an existing one, the existing one will be overwritten silently.
      * 如果标识相同 会覆盖
      * The following is an example for registering two sub-modules:
      *
      * ~~~
      * [
      *     'comment' => [
      *         'class' => 'app\modules\comment\CommentModule',
      *         'db' => 'db',
      *     ],
      *     'booking' => ['class' => 'app\modules\booking\BookingModule'],
      * ]
      * ~~~
      *
      * @param array $modules modules (id => module configuration or instances)
      */
     public function setModules($modules)
     {
         foreach ($modules as $id => $module) {
             $this->_modules[$id] = $module; //注册子模块，覆盖同名模块
         }
     }

     /**
      * Runs a controller action specified by a route.   运行路由中指定的控制器方法
      * This method parses the specified route and creates the corresponding child module(s), controller and action
      * instances. It then calls [[Controller::runAction()]] to run the action with the given parameters.
      * If the route is empty, the method will use [[defaultRoute]].
      * 解析指定的路由，创建对应的子模块、控制器、方法实例，调用[[Controller::runAction()]]给定的参数运行控制器中的方法
      * @param string $route the route that specifies the action.    指定行动的路线。
      * @param array $params the parameters to be passed to the action 操作的参数
      * @return mixed the result of the action.  操作结果
      * @throws InvalidRouteException if the requested route cannot be resolved into an action successfully
      */
     public function runAction($route, $params = [])
     {
         $parts = $this->createController($route); //根据路由创建控制器
         if (is_array($parts)) {
             /* @var $controller Controller */
             list($controller, $actionID) = $parts; //获得$actionId和$controller
             $oldController = Yii::$app->controller;
             Yii::$app->controller = $controller;
             $result = $controller->runAction($actionID, $params); //运行控制器 加载action方法
             Yii::$app->controller = $oldController;

             return $result;
         } else {
             $id = $this->getUniqueId();
             throw new InvalidRouteException('Unable to resolve the request "' . ($id === '' ? $route : $id . '/' . $route) . '".');
         }
     }

     /**
      * Creates a controller instance based on the given route.
      * 根据给定的路径创建一个控制器实例。
      * The route should be relative to this module. The method implements the following algorithm
      * to resolve the given route:
      * 相对这个模块的路径。该方法实现了以下算法来解决给定的路径：
      * 1. If the route is empty, use [[defaultRoute]];   路径为空，调用默认的路径
      * 2. If the first segment of the route is a valid module ID as declared in [[modules]],
      *    call the module's `createController()` with the rest part of the route;
      * 3. If the first segment of the route is found in [[controllerMap]], create a controller
      *    based on the corresponding configuration found in [[controllerMap]];
      * 4. The given route is in the format of `abc/def/xyz`. Try either `abc\DefController`
      *    or `abc\def\XyzController` class within the [[controllerNamespace|controller namespace]].
      *
      * If any of the above steps resolves into a controller, it is returned together with the rest
      * part of the route which will be treated as the action ID. Otherwise, false will be returned.
      *
      * @param string $route the route consisting of module, controller and action IDs.
      * 由模块、控制器和动作标识组成的路径。
      * @return array|boolean If the controller is created successfully, it will be returned together
      * with the requested action ID. Otherwise false will be returned.
      * 如果控制器成功创建，将与被请求的操作标识一起返回，否则将返回false。
      * @throws InvalidConfigException if the controller class and its file do not match.
      * 如果控制器类及其文件不匹配，抛出异常
      */
     public function createController($route)
     {
         if ($route === '') {//路径为空，调用默认的路径
             $route = $this->defaultRoute;
         }

         // double slashes or leading/ending slashes may cause substr problem
         $route = trim($route, '/'); //去掉两边的反斜线，
         if (strpos($route, '//') !== false) {
             return false; //如果路径中包含双斜线，返回false
         }

         if (strpos($route, '/') !== false) {
             list ($id, $route) = explode('/', $route, );//将路径按反斜线分割为两个元素的数组,
         } else {
             $id = $route;
             $route = '';
         }

         // module and controller map take precedence  优先判断模块和控制器映射
         if (isset($this->controllerMap[$id])) {
             //如果$id是控制器ID，实例化控制器，返回控制器实例和后面的路径$route
             $controller = Yii::createObject($this->controllerMap[$id], [$id, $this]);
             return [$controller, $route];
         }
         $module = $this->getModule($id);
         if ($module !== null) {//如果$id是模块ID，实例化控制器，返回控制器实例和后面的路径$route
             return $module->createController($route);
         }

         if (($pos = strrpos($route, '/')) !== false) {
             //上面两种情况都不是，则表示还有子模块，构造子模块的标识
             $id .= '/' . substr($route, , $pos);
             $route = substr($route, $pos + );
         }

         $controller = $this->createControllerByID($id);
         if ($controller === null && $route !== '') {//实例化控制器 组装控制器实例和后面的路径$route
             $controller = $this->createControllerByID($id . '/' . $route);
             $route = '';
         }
         //存在返回控制器实例和后面的路径$route，否则返回false
         return $controller === null ? false : [$controller, $route];
     }

     /**
      * Creates a controller based on the given controller ID.
      * 根据给定的控制器标识创建控制器
      * The controller ID is relative to this module. The controller class
      * should be namespaced under [[controllerNamespace]].
      * 当前模块的控制器标识，控制器类应在 [[controllerNamespace]]的命名空间下
      * Note that this method does not check [[modules]] or [[controllerMap]].
      *
      * @param string $id the controller ID  控制器标识
      * @return Controller the newly created controller instance, or null if the controller ID is invalid.
      *  新创建的控制器实例，为null则控制器标识无效
      * @throws InvalidConfigException if the controller class and its file name do not match.
      * This exception is only thrown when in debug mode.
      */
     public function createControllerByID($id)
     {
         $pos = strrpos($id, '/');
         if ($pos === false) {
             $prefix = ''; //是否包含反斜线，
             $className = $id;
         } else {//将路径按反斜线分割为两个元素
             $prefix = substr($id, , $pos + );
             $className = substr($id, $pos + );
         }

         if (!preg_match('%^[a-z][a-z0-9\\-_]*$%', $className)) {
             return null;//正则判断是否符合规则
         }
         if ($prefix !== '' && !preg_match('%^[a-z0-9_/]+$%i', $prefix)) {
             return null;
         }
         //组装控制器名
         $className = str_replace(' ', '', ucwords(str_replace('-', ' ', $className))) . 'Controller';
         $className = ltrim($this->controllerNamespace . '\\' . str_replace('/', '\\', $prefix)  . $className, '\\');
         if (strpos($className, '-') !== false || !class_exists($className)) {
             return null; //控制器名有 ‘-’或不存在则为null
         }

         if (is_subclass_of($className, 'yii\base\Controller')) {//检查对象是否有父类或子类
             return Yii::createObject($className, [$id, $this]); //创建控制器
         } elseif (YII_DEBUG) {
             throw new InvalidConfigException("Controller class must extend from \\yii\\base\\Controller.");
         } else {
             return null;
         }
     }

     /**
      * This method is invoked right before an action within this module is executed.
      * 当前模块的Action执行前调用的方法，将触发[[EVENT_BEFORE_ACTION]]事件
      * The method will trigger the [[EVENT_BEFORE_ACTION]] event. The return value of the method
      * will determine whether the action should continue to run.
      * 如果返回true，Action方法才会执行
      * If you override this method, your code should look like the following:
      *
      * ```php
      * public function beforeAction($action)
      * {
      *     if (parent::beforeAction($action)) {
      *         // your custom code here
      *         return true;  // or false if needed
      *     } else {
      *         return false;
      *     }
      * }
      * ```
      *
      * @param Action $action the action to be executed. 要执行的操作
      * @return boolean whether the action should continue to be executed.   是否执行操作
      */
     public function beforeAction($action)
     {
         $event = new ActionEvent($action);
         $this->trigger(self::EVENT_BEFORE_ACTION, $event);//触发beforeAction事件
         return $event->isValid;
     }

     /**
      * This method is invoked right after an action within this module is executed.
      * 当前模块的Action执行后调用的方法，触发[[EVENT_AFTER_ACTION]]事件
      * The method will trigger the [[EVENT_AFTER_ACTION]] event. The return value of the method
      * will be used as the action return value.
      * 如果返回true，后面的代码才会继续执行
      * If you override this method, your code should look like the following:
      *
      * ```php
      * public function afterAction($action, $result)
      * {
      *     $result = parent::afterAction($action, $result);
      *     // your custom code here
      *     return $result;
      * }
      * ```
      *
      * @param Action $action the action just executed.  执行的操作
      * @param mixed $result the action return result.   执行结果
      * @return mixed the processed action result.   处理结果
      */
     public function afterAction($action, $result)
     {
         $event = new ActionEvent($action);
         $event->result = $result;
         $this->trigger(self::EVENT_AFTER_ACTION, $event);//触发beforeAction事件
         return $event->result;
     }
 }