Yii2 missing required parameter in a constructor - yii2

Question

I've created a new XmlResponseFormatter and now I want to change the rootTag.
class newXmlResponseFormatter extends XmlResponseFormatter
{
/**
* #var string the name of the root element.
*
*/
public $rootTag;
public function __construct($rootTag) {
parent::__construct();
$this->rootTag = $rootTag;
}
}
From a controller I set that value:
$xmlFormater = new newXmlResponseFormatter('newRootTag');
In the controller that value is available, and it sets in $rootTag but it threw the following exception:
exception 'yii\base\InvalidConfigException' with message 'Missing required parameter "rootTag" when instantiating "app\components\override\newXmlResponseFormatter".' in /var/www/html/Admin/vendor/yiisoft/yii2/di/Container.php:451
Does anyone know what can be a problem?
Thanks in advance!

Answer 1

First parameter in XmlResponseFormatter is $config, because XmlResponseFormatter extends Object class. You are violated liskov substitution principle.
You should rewrite your constructor like this:
class newXmlResponseFormatter extends XmlResponseFormatter
{
/**
* #var string the name of the root element.
*
*/
public $rootTag;
/**
* newXmlResponseFormatter constructor.
*
* #param string $rootTag
* #param array $config
*/
public function __construct($rootTag, $config = [])
{
$this->rootTag = $rootTag;
parent::__construct($config);
}
}
In yii2 you should call parent constructor after your code, and call parent init before your code.
$config need for simple configure model like this:
new newXmlResponseFormatter(['rootTag' => 'newRootTag']);