yii\base\Controller::renderFile PHP Method

Renders a view file.

public renderFile ( string $file, array $params = [] ) : string
$file	string	the view file to be rendered. This can be either a file path or a path alias.
$params	array	the parameters (name-value pairs) that should be made available in the view.
return	string	the rendering result.

    public function renderFile($file, $params = [])
    {
        return $this->getView()->renderFile($file, $params, $this);
    }

Controller