yii2源码学习笔记(十一）

Controller控制器类，是所有控制器的基类，用于调用模型和布局。

 <?php
 /**
  * @link http://www.yiiframework.com/
  * @copyright Copyright (c) 2008 Yii Software LLC
  * @license http://www.yiiframework.com/license/
  */

 namespace yii\base;

 use Yii;

 /**
  * Controller is the base class for classes containing controller logic.
  *  控制器，是所用控制器类的基类
  * @property Module[] $modules All ancestor modules that this controller is located within. This property is
  * read-only.只读属性  当前控制器的所有模块
  * @property string $route The route (module ID, controller ID and action ID) of the current request. This
  * property is read-only.当前请求的路径  只读属性 可以获取到请求的路径
  * @property string $uniqueId The controller ID that is prefixed with the module ID (if any). This property is
  * read-only.为前缀的controller ID  唯一标识
  * @property View|\yii\web\View $view The view object that can be used to render views or view files.
  * 视图用来传递视图或视图文件.
  * @property string $viewPath The directory containing the view files for this controller. This property is
  * read-only. 包含当前控制器的视图目录
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
 class Controller extends Component implements ViewContextInterface
 {
     /**
      * @event ActionEvent an event raised right before executing a controller action.
      * ActionEvent事件提出正确的执行器动作之前执行。
      * You may set [[ActionEvent::isValid]] to be false to cancel the action execution.
      * 如果对事件的isValid属性设置为false，将取消action的执行
      */
     const EVENT_BEFORE_ACTION = 'beforeAction';
     /**
      * @event ActionEvent an event raised right after executing a controller action.
      * 在执行controller操作后触发的事件
      */
     const EVENT_AFTER_ACTION = 'afterAction';

     /**
      * @var string the ID of this controller.
      * 控制器id
      */
     public $id;
     /**
      * @var Module $module the module that this controller belongs to.
      * 所属模块
      */
     public $module;
     /**
      * @var string the ID of the action that is used when the action ID is not specified
      * in the request. Defaults to 'index'.控制器中默认动作，默认为index
      */
     public $defaultAction = 'index';
     /**
      * @var string|boolean the name of the layout to be applied to this controller's views.
      * 布局的名称 应用到该控制器的视图。
      * This property mainly affects the behavior of [[render()]].此属性主要影响[[render()]]行为
      * Defaults to null, meaning the actual layout value should inherit that from [[module]]'s layout value.
      * If false, no layout will be applied.
      * 如果设置为false，则不使用布局文件
      */
     public $layout;
     /**
      * @var Action the action that is currently being executed. This property will be set
      * by [[run()]] when it is called by [[Application]] to run an action.
      * 当前执行的操作，可在事件中根据这个action来执行不同的操作
      */
     public $action;

     /**
      * @var View the view object that can be used to render views or view files.
      * 视图对象，用来定义输出的视图文件
      */
     private $_view;

     /**
      * @param string $id the ID of this controller.控制器的ID
      * @param Module $module the module that this controller belongs to.控制器的模块
      * @param array $config name-value pairs that will be used to initialize the object properties.
      * 初始化对像时的配置文件
      */
     public function __construct($id, $module, $config = [])
     {
         //初始化控制器id，模块，根据配置文件初始化控制器对象
         $this->id = $id;
         $this->module = $module;
         parent::__construct($config);
     }

     /**
      * Declares external actions for the controller.定义action声明控制器的外部操作
      * This method is meant to be overwritten to declare external actions for the controller.
      * It should return an array, with array keys being action IDs, and array values the corresponding
      * action class names or action configuration arrays. For example,
      * 这个方法指定独立的action，返回格式为数组，name为action的id,value为action类的实现，
      * ~~~
      * return [
      *     'action1' => 'app\components\Action1',
      *     'action2' => [
      *         'class' => 'app\components\Action2',
      *         'property1' => 'value1',
      *         'property2' => 'value2',
      *     ],
      * ];
      * ~~~
      *
      * [[\Yii::createObject()]] will be used later to create the requested action
      * using the configuration provided here.
      * 使用此处提供的配置来创建请求的操作。
      */
     public function actions()
     {
         return [];
     }

     /**
      * Runs an action within this controller with the specified action ID and parameters.
      * 控制器中运行指定的操作标识和参数。
      * If the action ID is empty, the method will use [[defaultAction]].
      * 如果没有定义ID，会调用默认操作
      * @param string $id the ID of the action to be executed. 要执行的动作标识。
      * @param array $params the parameters (name-value pairs) to be passed to the action.
      * 传递给操作的参数。
      * @return mixed the result of the action.  操作结果
      * @throws InvalidRouteException if the requested action ID cannot be resolved into an action successfully.
      * @see createAction()
      */
     public function runAction($id, $params = [])
     {
         $action = $this->createAction($id);//创建操作
         if ($action === null) {//创建失败，抛出异常
             throw new InvalidRouteException('Unable to resolve the request: ' . $this->getUniqueId() . '/' . $id);
         }

         Yii::trace("Route to run: " . $action->getUniqueId(), __METHOD__);

         if (Yii::$app->requestedAction === null) {
             // 记录当前的操作为requestedAction
             Yii::$app->requestedAction = $action;
         }

         $oldAction = $this->action;//将操作中的信息保存
         $this->action = $action;//写入属性
         //保存当前控制器的所有父模块
         $modules = [];
         $runAction = true;

         // call beforeAction on modules 从外到里一层层执行module的beforeAction
         foreach ($this->getModules() as $module) {
             if ($module->beforeAction($action)) {
                  // 将执行成功的module放入到$modules中，顺序会颠倒
                 array_unshift($modules, $module);
             } else {
                  // 执行失败，就标记一下
                 $runAction = false;
                 break;
             }
         }

         $result = null;

         if ($runAction && $this->beforeAction($action)) {
             // run the action 执行成功就执行action
             $result = $action->runWithParams($params);
             // 执行controller本身的afterAction
             $result = $this->afterAction($action, $result);

             // call afterAction on modules 从里到外一层层执行所有
             foreach ($modules as $module) {
                 /* @var $module Module */
                 $result = $module->afterAction($action, $result);
             }
         }

         $this->action = $oldAction;

         return $result;
     }

yii2\base\Controller.php