Yii/web中的Controller类，实现参数绑定，启动csrf验证功能，重定向页面功能：
namespace yii\web;
use Yii;
use yii\base\InlineAction;
use yii\helpers\Url;
/**
* Controller is the base class of web controllers.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class Controller extends \yii\base\Controller
{
/**
* @var boolean whether to enable CSRF validation for the actions in this controller.
* @var boolean 是否启动CSRF验证标记
* CSRF validation is enabled only when both this property and [[Request::enableCsrfValidation]] are true.
*/
public $enableCsrfValidation = true;
/**
* @var array the parameters bound to the current action.
* @var array 绑定到当前操作的参数
*/
public $actionParams = [];
/**
* Renders a view in response to an AJAX request.
* 这个渲染的结果用来作为ajax请求的的响应
*
* This method is similar to [[renderPartial()]] except that it will inject into
* the rendering result with JS/CSS scripts and files which are registered with the view.
* For this reason, you should use this method instead of [[renderPartial()]] to render
* a view to respond to an AJAX request.
* 这个方法和renderPartial类似，但这个返回的结果中会包含css/js以及其它在view中注册的文件。
*
* @param string $view the view name. Please refer to [[render()]] on how to specify a view name.
* @param array $params the parameters (name-value pairs) that should be made available in the view.
* @return string the rendering result.
*/
public function renderAjax($view, $params = [])
{
return $this->getView()->renderAjax($view, $params, $this);
}
/**
* Binds the parameters to the action.
* 基类的 action 中绑定参数功能的实现
* This method is invoked by [[\yii\base\Action]] when it begins to run with the given parameters.
* This method will check the parameter names that the action requires and return
* the provided parameters according to the requirement. If there is any missing parameter,
* an exception will be thrown.
* 根据action中定义的参数，从$_GET中取对应的值，
* 如果没有，则抛出异常
* @param \yii\base\Action $action the action to be bound with parameters
* @param array $params the parameters to be bound to the action
* @return array the valid parameters that the action can run with.
* @throws BadRequestHttpException if there are missing or invalid parameters.
*/
public function bindActionParams($action, $params)
{
if ($action instanceof InlineAction) {//如果action继承InlineAction
$method = new \ReflectionMethod($this, $action->actionMethod);//通过反射得到动作action的方法信息
} else {
$method = new \ReflectionMethod($action, 'run');//如果action继承Action基类，通过反射得到动作action的方法信息，并实现里面的run方法
}
$args = [];
$missing = [];
$actionParams = [];
foreach ($method->getParameters() as $param) {
//获取在action中定义的参数的名称
$name = $param->getName();
if (array_key_exists($name, $params)) {
if ($param->isArray()) {//如果参数是数组类型的，如果从传入的参数中取得的数据是数组则返回，否则将得到的参数转换为数组
$args[] = $actionParams[$name] = (array) $params[$name];
} elseif (!is_array($params[$name])) {//如果不是数组，直接返回传入的参数中对应的结果
$args[] = $actionParams[$name] = $params[$name];
} else {
throw new BadRequestHttpException(Yii::t('yii', 'Invalid data received for parameter "{param}".', [
'param' => $name,
]));
}
unset($params[$name]);
} elseif ($param->isDefaultValueAvailable()) { //如果默认有默认值取默认值
$args[] = $actionParams[$name] = $param->getDefaultValue();
} else {//action中定义的参数没有在传入的参数中找到，标记的missing中
$missing[] = $name;
}
}
if (!empty($missing)) {//action中的参数有缺少，抛出异常
throw new BadRequestHttpException(Yii::t('yii', 'Missing required parameters: {params}', [
'params' => implode(', ', $missing),
]));
}
$this->actionParams = $actionParams;
return $args;
}
/**
* @inheritdoc 重写基类的beforeAction
*/
public function beforeAction($action)
{
if (parent::beforeAction($action)) {
//父类的beforAction方法执行成功后，启动csrf验证功能
if ($this->enableCsrfValidation && Yii::$app->getErrorHandler()->exception === null && !Yii::$app->getRequest()->validateCsrfToken()) {
throw new BadRequestHttpException(Yii::t('yii', 'Unable to verify your data submission.'));
}
return true;
}
return false;
}
/**
* Redirects the browser to the specified URL.
* 重定向方法[[Response::redirect()]]的短方法
* This method is a shortcut to [[Response::redirect()]].
*
* You can use it in an action by returning the [[Response]] directly:
* 下面的例子是重定向到longin
* ```php
* // stop executing this action and redirect to login page
* return $this->redirect(['login']);
* ```
*
* @param string|array $url the URL to be redirected to. This can be in one of the following formats:
* @param string|array $url 重定向的URL，有下列三种形式
*
* - a string representing a URL (e.g. "http://example.com")
* 一个字符串URL
* - a string representing a URL alias (e.g. "@example.com")
* 别名形式的URL
* - an array in the format of `[$route, ...name-value pairs...]` (e.g. `['site/index', 'ref' => 1]`)
* 数组，第一个元素为生成路径的参数，后面的元素为链接中传递的参数
* [[Url::to()]] will be used to convert the array into a URL.
*
* Any relative URL will be converted into an absolute one by prepending it with the host info
* of the current request.
* 如果传入的是相对的url，都会根据当前请求的host info 转换为绝对url
*
* @param integer $statusCode the HTTP status code. Defaults to 302.
* See <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html>
* for details about HTTP status code
* @return Response the current response object
*/
public function redirect($url, $statusCode = 302)
{
return Yii::$app->getResponse()->redirect(Url::to($url), $statusCode);
}
/**
* Redirects the browser to the home page.
* 重定向到首页
*
* You can use this method in an action by returning the [[Response]] directly:
*
* ```php
* // stop executing this action and redirect to home page
* return $this->goHome();
* ```
*
* @return Response the current response object
*/
public function goHome()
{
return Yii::$app->getResponse()->redirect(Yii::$app->getHomeUrl());
}
/**
* Redirects the browser to the last visited page.
* 返回上一页
*
* You can use this method in an action by returning the [[Response]] directly:
*
* ```php
* // stop executing this action and redirect to last visited page
* return $this->goBack();
* ```
*
* For this function to work you have to [[User::setReturnUrl()|set the return URL]] in appropriate places before.
*
* @param string|array $defaultUrl the default return URL in case it was not set previously.
* If this is null and the return URL was not set previously, [[Application::homeUrl]] will be redirected to.
* Please refer to [[User::setReturnUrl()]] on accepted format of the URL.
* @return Response the current response object
* @see User::getReturnUrl()
*/
public function goBack($defaultUrl = null)
{
return Yii::$app->getResponse()->redirect(Yii::$app->getUser()->getReturnUrl($defaultUrl));
}
/**
* Refreshes the current page.
* 刷新页面
* This method is a shortcut to [[Response::refresh()]].
*
* You can use it in an action by returning the [[Response]] directly:
*
* ```php
* // stop executing this action and refresh the current page
* return $this->refresh();
* ```
*
* @param string $anchor the anchor that should be appended to the redirection URL.
* Defaults to empty. Make sure the anchor starts with '#' if you want to specify it.
* @return Response the response object itself
*/
public function refresh($anchor = '')
{
return Yii::$app->getResponse()->redirect(Yii::$app->getRequest()->getUrl() . $anchor);
}
}