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。

  1 php
  2 /**
  3  * @link http://www.yiiframework.com/
  4  * @copyright Copyright (c) 2008 Yii Software LLC
  5  * @license http://www.yiiframework.com/license/
  6  */
  7 
  8 namespace yii\base;
  9 
 10 use Yii;
 11 
 12 /**
 13  * Controller is the base class for classes containing controller logic.
 14  *  控制器，是所用控制器类的基类
 15  * @property Module[] $modules All ancestor modules that this controller is located within. This property is
 16  * read-only.只读属性  当前控制器的所有模块
 17  * @property string $route The route (module ID, controller ID and action ID) of the current request. This
 18  * 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
 19  * @property string $uniqueId The controller ID that is prefixed with the module ID (if any). This property is
 20  * read-only.为前缀的controller ID  唯一标识
 21  * @property View|\yii\web\View $view The view object that can be used to render views or view files.
 22  * 视图用来传递视图或视图文件.
 23  * @property string $viewPath The directory containing the view files for this controller. This property is
 24  * read-only. 包含当前控制器的视图目录
 25  *
 26  * @author Qiang Xue  27  * @since 2.0
 28  */
 29 class Controller extends Component implements ViewContextInterface
 30 {
 31     /**
 32      * @event ActionEvent an event raised right before executing a controller action.
 33      * ActionEvent事件提出正确的执行器动作之前执行。
 34      * You may set [[ActionEvent::isValid]] to be false to cancel the action execution.
 35      * 如果对事件的isValid属性设置为false，将取消action的执行
 36      */
 37     const EVENT_BEFORE_ACTION = 'beforeAction';
 38     /**
 39      * @event ActionEvent an event raised right after executing a controller action.
 40      * 在执行controller操作后触发的事件
 41      */
 42     const EVENT_AFTER_ACTION = 'afterAction';
 43 
 44     /**
 45      * @var string the ID of this controller.
 46      * 控制器id
 47      */
 48     public $id;
 49     /**
 50      * @var Module $module the module that this controller belongs to.
 51      * 所属模块
 52      */
 53     public $module;
 54     /**
 55      * @var string the ID of the action that is used when the action ID is not specified
 56      * in the request. Defaults to 'index'.控制器中默认动作，默认为index
 57      */
 58     public $defaultAction = 'index';
 59     /**
 60      * @var string|boolean the name of the layout to be applied to this controller's views.
 61      * 布局的名称 应用到该控制器的视图。
 62      * This property mainly affects the behavior of [[render()]].此属性主要影响[[render()]]行为
 63      * Defaults to null, meaning the actual layout value should inherit that from [[module]]'s layout value.
 64      * If false, no layout will be applied. 
 65      * 如果设置为false，则不使用布局文件
 66      */
 67     public $layout;
 68     /**
 69      * @var Action the action that is currently being executed. This property will be set
 70      * by [[run()]] when it is called by [[Application]] to run an action.
 71      * 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
 72      */
 73     public $action;
 74 
 75     /**
 76      * @var View the view object that can be used to render views or view files.
 77      * 视图对象，用来定义输出的视图文件
 78      */
 79     private $_view;
 80 
 81 
 82     /**
 83      * @param string $id the ID of this controller.控制器的ID
 84      * @param Module $module the module that this controller belongs to.控制器的模块
 85      * @param array $config name-value pairs that will be used to initialize the object properties.
 86      * 初始化对像时的配置文件
 87      */
 88     public function __construct($id, $module, $config = [])
 89     {
 90         //初始化控制器id，模块，根据配置文件初始化控制器对象
 91         $this->id = $id;
 92         $this->module = $module;
 93         parent::__construct($config);
 94     }
 95 
 96     /**
 97      * Declares external actions for the controller.定义action声明控制器的外部操作
 98      * This method is meant to be overwritten to declare external actions for the controller.
 99      * It should return an array, with array keys being action IDs, and array values the corresponding
100      * action class names or action configuration arrays. For example,
101      * 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，
102      * ~~~
103      * return [
104      *     'action1' => 'app\components\Action1',
105      *     'action2' => [
106      *         'class' => 'app\components\Action2',
107      *         'property1' => 'value1',
108      *         'property2' => 'value2',
109      *     ],
110      * ];
111      * ~~~
112      *
113      * [[\Yii::createObject()]] will be used later to create the requested action
114      * using the configuration provided here.
115      * 使用此处提供的配置来创建请求的操作。
116      */
117     public function actions()
118     {
119         return [];
120     }
121 
122     /**
123      * Runs an action within this controller with the specified action ID and parameters.
124      * 控制器中运行指定的操作标识和参数。
125      * If the action ID is empty, the method will use [[defaultAction]].
126      * 如果没有定义ID，会调用默认操作
127      * @param string $id the ID of the action to be executed. 要执行的动作标识。
128      * @param array $params the parameters (name-value pairs) to be passed to the action.
129      * 传递给操作的参数。
130      * @return mixed the result of the action.  操作结果
131      * @throws InvalidRouteException if the requested action ID cannot be resolved into an action successfully.
132      * @see createAction()
133      */
134     public function runAction($id, $params = [])
135     {
136         $action = $this->createAction($id);//创建操作
137         if ($action === null) {//创建失败，抛出异常
138             throw new InvalidRouteException('Unable to resolve the request: ' . $this->getUniqueId() . '/' . $id);
139         }
140 
141         Yii::trace("Route to run: " . $action->getUniqueId(), __METHOD__);
142 
143         if (Yii::$app->requestedAction === null) {
144             // 记录当前的操作为requestedAction
145             Yii::$app->requestedAction = $action;
146         }
147 
148         $oldAction = $this->action;//将操作中的信息保存
149         $this->action = $action;//写入属性
150         //保存当前控制器的所有父模块
151         $modules = [];
152         $runAction = true;
153 
154         // call beforeAction on modules 从外到里一层层执行module的beforeAction
155         foreach ($this->getModules() as $module) {
156             if ($module->beforeAction($action)) {
157                  // 将执行成功的module放入到$modules中，顺序会颠倒
158                 array_unshift($modules, $module);
159             } else {
160                  // 执行失败，就标记一下
161                 $runAction = false;
162                 break;
163             }
164         }
165 
166         $result = null;
167 
168         if ($runAction && $this->beforeAction($action)) {
169             // run the action 执行成功就执行action
170             $result = $action->runWithParams($params);
171             // 执行controller本身的afterAction
172             $result = $this->afterAction($action, $result);
173 
174             // call afterAction on modules 从里到外一层层执行所有
175             foreach ($modules as $module) {
176                 /* @var $module Module */
177                 $result = $module->afterAction($action, $result);
178             }
179         }
180 
181         $this->action = $oldAction;
182 
183         return $result;
184     }

yii2\base\Controller.php