public function process()
    {
        $this->processed = $this->isSubmitted();

        if ($this->processed) {
            $this->processEncoding();
            $this->processHiddenFields();

            foreach ($this->children as $child) {
                if ($child !== null && !$child->isProcessed()) {
                    $child->process();
                }
            }
        }
    }