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