如果做API的话，如何使别人再调用你的接口时能够有一个统一标准的json或者jsonp格式，然而 json响应的格式和内容，每个人的约定都是有差异的，所以我们必须再数据出去之前做一定的处理。
1.首先我们需要初始化去调用beforeSend，因为我们需要对beforesend做一些处理，以下是init初始化处理代码：
/**
* (non-PHPdoc)
* @see \yii\base\Object::init()
*/
public function init()
{
parent::init(); //绑定beforeSend事件，更改数据输出格式
Yii::$app->getResponse()->on(Response::EVENT_BEFORE_SEND, [$this, 'beforeSend']);
}2.然后我们就需要对beforesend进行处理，处理点有下面几个重点：
1>更改数据输出格式
2>默认情况下输出Json数据
3>如果客户端请求时有传递$_GET['callback']参数，输出Jsonp格式
4>请求正确时数据为 {"success":true,"data":{...}}
5>请求错误时数据为 {"success":false,"data":{"name":"Not Found","message":"页面未找到。","code":0,"status":404}}
6>具体代码如下：
/**
* 更改数据输出格式
* 默认情况下输出Json数据
* 如果客户端请求时有传递$_GET['callback']参数，输入Jsonp格式
* 请求正确时数据为 {"success":true,"data":{...}}
* 请求错误时数据为 {"success":false,"data":{"name":"Not Found","message":"页面未找到。","code":0,"status":404}}
* @param \yii\base\Event $event
*/
public function beforeSend($event)
{ /* @var $response \yii\web\Response */
$response = $event->sender;
$isSuccessful = $response->isSuccessful; if ($response->statusCode>=400) { //异常处理
if (true && $exception = Yii::$app->getErrorHandler()->exception) {
$response->data = $this->convertExceptionToArray($exception);
} //Model出错了
if ($response->statusCode==422) {
$messages=[]; foreach ($response->data as $v) {
$messages[] = $v['message'];
} //请求错误时数据为 {"success":false,"data":{"name":"Not Found","message":"页面未找到。","code":0,"status":404}}
$response->data = [ 'name'=> 'valide error', 'message'=> implode(" ", $messages), 'info'=>$response->data
];
}
$response->statusCode = 200;
} elseif ($response->statusCode>=300) {
$response->statusCode = 200;
$response->data = $this->convertExceptionToArray(new ForbiddenHttpException(Yii::t('yii', 'Login Required')));
} //请求正确时数据为 {"success":true,"data":{...}}
$response->data = [ 'success' => $isSuccessful, 'data' => $response->data,
];
$response->format = Response::FORMAT_JSON;
\Yii::$app->getResponse()->getHeaders()->set('Access-Control-Allow-Origin', '*');
\Yii::$app->getResponse()->getHeaders()->set('Access-Control-Allow-Credentials', 'true'); //jsonp 格式输出
if (isset($_GET['callback'])) {
$response->format = Response::FORMAT_JSONP;
$response->data = [ 'callback' => $_GET['callback'], 'data'=>$response->data,
];
}
}3.针对请求可能会发生一些异常，同样我们也需要对异常进行一些标准化处理，将异常转换为array输出，具体代码如下：
/**
* 将异常转换为array输出
* @see \yii\web\ErrorHandle
* @param \Exception $exception
* @return multitype:string NULL Ambigous <string, \yii\base\string> \yii\web\integer \yii\db\array multitype:string NULL Ambigous <string, \yii\base\string> \yii\web\integer \yii\db\array
*/
protected function convertExceptionToArray($exception)
{ if (!YII_DEBUG && !$exception instanceof UserException && !$exception instanceof HttpException) {
$exception = new HttpException(500, Yii::t('yii', 'An internal server error occurred.'));
}
$array = [ 'name' => ($exception instanceof Exception || $exception instanceof ErrorException) ? $exception->getName() : 'Exception', 'message' => $exception->getMessage(), 'code' => $exception->getCode(),
]; if ($exception instanceof HttpException) {
$array['status'] = $exception->statusCode;
} if (YII_DEBUG) {
$array['type'] = get_class($exception); if (!$exception instanceof UserException) {
$array['file'] = $exception->getFile();
$array['line'] = $exception->getLine();
$array['stack-trace'] = explode("\n", $exception->getTraceAsString()); if ($exception instanceof \yii\db\Exception) {
$array['error-info'] = $exception->errorInfo;
}
}
} if (($prev = $exception->getPrevious()) !== null) {
$array['previous'] = $this->convertExceptionToArray($prev);
} return $array;
}好了，这样我们就有了标准同一个的api接口返回数据格式了，在调用接口的人员也不用为了格式不统一感到烦恼
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