<?php namespace common\behaviors; use yii\filters\Cors; class GsCors extends Cors { public function prepareHeaders($requestHeaders){ $responseHeaders = parent::prepareHeaders($requestHeaders); if (isset($this->cors['Access-Control-Allow-Headers'])) { $responseHeaders['Access-Control-Allow-Headers'] = implode(', ', $this->cors['Access-Control-Allow-Headers']); } return $responseHeaders; } }