DataProviderManager::getDataProviderValue

public function getDataProviderValue(DataProvider $dataProvider, $placeholder)
{
	if($placeholder !== 0 && empty($placeholder))
	{
		return false;
	}

	if(!$dataProvider->isLoaded())
	{
		return false;
	}

	$placeholderParts = explode('.', $placeholder);
	if(count($placeholderParts) > 1)
	{
		$provider = $this->getDataProviderValue($dataProvider, $placeholderParts[0]);
		if($provider && $provider instanceof DataProvider)
		{
			$value = $provider->getValue(implode('.', array_slice($placeholderParts, 1)));
			if($this->getContext()->getIsCheckAccess() && !$this->checkDataProviderAccess($provider))
			{
				$value = false;
			}
		}
		else
		{
			$value = false;
		}
	}
	else
	{
		$value = $this->calculateDataProviderValue($dataProvider, $placeholder);
	}

	return $value;
}