Neos\FluidAdaptor\ViewHelpers\Form\SelectViewHelper::getOptionValueScalar PHP Method

    protected function getOptionValueScalar($valueElement)
    {
        if (is_object($valueElement)) {
            if ($this->hasArgument('optionValueField')) {
                return ObjectAccess::getPropertyPath($valueElement, $this->arguments['optionValueField']);
            } elseif ($this->persistenceManager->getIdentifierByObject($valueElement) !== null) {
                return $this->persistenceManager->getIdentifierByObject($valueElement);
            } else {
                return (string) $valueElement;
            }
        } else {
            return $valueElement;
        }
    }