yii2源码学习笔记(八）

Action是所有控制器的基类，接下来了解一下它的源码。yii2\base\Action.php

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

 namespace yii\base;

 use Yii;

 /**
  * Action is the base class for all controller action classes.
  * 是所有控制器的基类
  * Action provides a way to divide a complex controller into
  * smaller actions in separate class files.
  * 控制器提供了一种重复使用操作方法的代码，在多个控制器或不同的项目中使用
  * Derived classes must implement a method named `run()`. This method
  * will be invoked by the controller when the action is requested.
  * The `run()` method can have parameters which will be filled up
  * with user input values automatically according to their names.
  * 派生类必须实现一个名为run()的方法，这个方法会在控制器被请求时调用。
  * 它可以有参数，将用户输入值的根据他们的名字自动填补。
  * For example, if the `run()` method is declared as follows:
  * 例：run()方法调用声明如下：
  * ~~~
  * public function run($id, $type = 'book') { ... }
  * ~~~
  *
  * And the parameters provided for the action are: `['id' => 1]`.
  * Then the `run()` method will be invoked as `run(1)` automatically.
  * 并且提供了操作的参数 ['id'=>1];
  * 当run(1)时自动调用run();
  * @property string $uniqueId The unique ID of this action among the whole application. This property is
  * read-only.
  * 整个应用程序中，这一行动的唯一标识。此属性是只读
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
 class Action extends Component
 {
     /**
      * @var string ID of the action     ID的动作
      */
     public $id;
     /**
      * @var Controller|\yii\web\Controller the controller that owns this action
      * 拥有这一行动的控制器
      */
     public $controller;

     /**
      * Constructor.
      * 构造函数
      * @param string $id the ID of this action  这一行动的ID
      * @param Controller $controller the controller that owns this action 拥有这一行动的控制器
      * @param array $config name-value pairs that will be used to initialize the object properties
      * 用来初始化对象属性的 name-value
      */
     public function __construct($id, $controller, $config = [])
     {
         $this->id = $id;
         $this->controller = $controller;
         //调用父类的__construct()方法
         parent::__construct($config);
     }

     /**
      * Returns the unique ID of this action among the whole application.
      * 返回整个应用程序中的唯一ID。
      * @return string the unique ID of this action among the whole application.
      * 在整个应用程序中，这一行动的唯一ID。
      */
     public function getUniqueId()
     {
         return $this->controller->getUniqueId() . '/' . $this->id;
     }

     /**
      * Runs this action with the specified parameters.  用指定的参数运行此操作。
      * This method is mainly invoked by the controller. 该方法主要由控制器调用。
      *
      * @param array $params the parameters to be bound to the action's run() method.绑定到行动的run()方法的参数。
      * @return mixed the result of the action   行动的结果  命名参数是否有效的
      * @throws InvalidConfigException if the action class does not have a run() method
      * 如果动作类没有run()方法 扔出异常
      */
     public function runWithParams($params)
     {
         if (!method_exists($this, 'run')) {//如果动作类没有run()方法 抛出异常
             throw new InvalidConfigException(get_class($this) . ' must define a "run()" method.');
         }
         //调用bindActionParams()方法将参数绑定到动作。
         $args = $this->controller->bindActionParams($this, $params);
         //记录跟踪消息
         Yii::trace('Running action: ' . get_class($this) . '::run()', __METHOD__);
         if (Yii::$app->requestedParams === null) {
             //请求的动作提供的参数
             Yii::$app->requestedParams = $args;
         }
         if ($this->beforeRun()) {
             //执行run()方法
             $result = call_user_func_array([$this, 'run'], $args);
             $this->afterRun();

             return $result;
         } else {
             return null;
         }
     }

     /**
      * This method is called right before `run()` is executed.
      * ` run() `执行前方法被调用。
      * You may override this method to do preparation work for the action run.
      * 可以重写此方法，为该操作运行的准备工作。
      * If the method returns false, it will cancel the action.
      * 如果该方法返回false，取消该操作。
      * @return boolean whether to run the action.
      */
     protected function beforeRun()
     {
         return true;
     }

     /**
      * This method is called right after `run()` is executed.       ` run() `执行后 方法被调用。
      * You may override this method to do post-processing work for the action run.
      * 可以重写此方法来处理该动作的后续处理工作。
      */
     protected function afterRun()
     {
     }
 }

接下来我们看一下事件参数相关重要的一个类ActionEvent。yii2\base\ActionEvent.php

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

 namespace yii\base;

 /**
  * ActionEvent represents the event parameter used for an action event.
  * 用于操作事件的事件参数
  * By setting the [[isValid]] property, one may control whether to continue running the action.
  * 通过设置[[isValid]]属性，控制是否继续运行action。
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
 class ActionEvent extends Event
 {
     /**
      * @var Action the action currently being executed
      * 目前正在执行的行动
      */
     public $action;
     /**
      * @var mixed the action result. Event handlers may modify this property to change the action result.
      * 操作结果 事件处理程序可以修改此属性来更改操作结果。
      */
     public $result;
     /**
      * @var boolean whether to continue running the action. Event handlers of
      * [[Controller::EVENT_BEFORE_ACTION]] may set this property to decide whether
      * to continue running the current action.
      * 是否继续运行该动作。设置[[Controller::EVENT_BEFORE_ACTION]]属性决定是否执行当前的操作
      */
     public $isValid = true;

     /**
      * Constructor.构造函数。
      * @param Action $action the action associated with this action event.与此事件相关联的动作。
      * @param array $config name-value pairs that will be used to initialize the object properties
      * 用来初始化对象属性的 name-value
      */
     public function __construct($action, $config = [])
     {
         $this->action = $action;
         parent::__construct($config);
     }
 }

今天最后看一下操作过滤器的基类吧ActionFilter。yii2\base\ActionFilter.php。

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

 namespace yii\base;

 /**
  * ActionFilter is the base class for action filters.
  * 是操作过滤器的基类。
  * An action filter will participate in the action execution workflow by responding to
  * the `beforeAction` and `afterAction` events triggered by modules and controllers.
  * 一个操作过滤器将参与行动的执行工作流程，通过触发模型和控制器的`beforeAction` 和`afterAction` 事件
  * Check implementation of [[\yii\filters\AccessControl]], [[\yii\filters\PageCache]] and [[\yii\filters\HttpCache]] as examples on how to use it.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
 class ActionFilter extends Behavior
 {
     /**
      * @var array list of action IDs that this filter should apply to. If this property is not set,
      * then the filter applies to all actions, unless they are listed in [[except]].
      * 操作标识列表。如果该属性未设置，过滤器适用于所有的行动，除非它们被列入[[except]]中。
      * If an action ID appears in both [[only]] and [[except]], this filter will NOT apply to it.
      * 如果一个操作ID 出现在[[only]] 和[[except]]中，该筛选器将不适用它
      * Note that if the filter is attached to a module, the action IDs should also include child module IDs (if any)
      * and controller IDs.
      * 如果过滤器是链接到一个模块，操作检测还应包括子模块和控制器
      *
      * @see except
      */
     public $only;
     /**
      * @var array list of action IDs that this filter should not apply to.
      * 此筛选器不应适用于操作ID。
      * @see only
      */
     public $except = [];

     /**
      * @inheritdoc
      * 将行为对象附加到组件。
      */
     public function attach($owner)
     {
         $this->owner = $owner;
         $owner->on(Controller::EVENT_BEFORE_ACTION, [$this, 'beforeFilter']);
     }

     /**
      * @inheritdoc
      * 将行为对象和组件分离。
      */
     public function detach()
     {
         if ($this->owner) {
             $this->owner->off(Controller::EVENT_BEFORE_ACTION, [$this, 'beforeFilter']);
             $this->owner->off(Controller::EVENT_AFTER_ACTION, [$this, 'afterFilter']);
             $this->owner = null;
         }
     }

     /**
      * @param ActionEvent $event    在动作之前调用
      */
     public function beforeFilter($event)
     {
         if (!$this->isActive($event->action)) {
             return;
         }

         $event->isValid = $this->beforeAction($event->action);
         if ($event->isValid) {
             // call afterFilter only if beforeFilter succeeds    beforeFilter 执行成功调用afterFilter
             // beforeFilter and afterFilter should be properly nested  两者要配合应用
             $this->owner->on(Controller::EVENT_AFTER_ACTION, [$this, 'afterFilter'], null, false);
         } else {
             $event->handled = true;
         }
     }

     /**
      * @param ActionEvent $event
      */
     public function afterFilter($event)
     {
         $event->result = $this->afterAction($event->action, $event->result);
         $this->owner->off(Controller::EVENT_AFTER_ACTION, [$this, 'afterFilter']);
     }

     /**
      * This method is invoked right before an action is to be executed (after all possible filters.)
      * 此方法是在一个动作之前被调用的（
      * You may override this method to do last-minute preparation for the action.
      * @param Action $action the action to be executed.要执行的动作
      * @return boolean whether the action should continue to be executed.
      * 是否应继续执行该动作。
      */
     public function beforeAction($action)
     {
         return true;
     }

     /**
      * This method is invoked right after an action is executed.
      * 此方法是在执行动作之后调用的。
      * You may override this method to do some postprocessing for the action.
      * @param Action $action the action just executed.  刚刚执行的动作
      * @param mixed $result the action execution result 行动执行结果
      * @return mixed the processed action result.   处理结果。
      */
     public function afterAction($action, $result)
     {
         return $result;
     }

     /**
      * Returns a value indicating whether the filer is active for the given action.
      * 返回一个值，给定的过滤器的行动是否为是积极的。
      * @param Action $action the action being filtered 被过滤的动作
      * @return boolean whether the filer is active for the given action.
      * 给定的过滤器的行动是否为是积极的。
      */
     protected function isActive($action)
     {
         if ($this->owner instanceof Module) {
             // convert action uniqueId into an ID relative to the module
             $mid = $this->owner->getUniqueId();
             $id = $action->getUniqueId();
             if ($mid !== '' && strpos($id, $mid) === ) {
                 $id = substr($id, strlen($mid) + );
             }
         } else {
             $id = $action->id;
         }
         return !in_array($id, $this->except, true) && (empty($this->only) || in_array($id, $this->only, true));
     }
 }