Field::getFetchDataModifiers

public function getFetchDataModifiers()
{
	if ($this->fetchDataModifiers === null)
	{
		$this->fetchDataModifiers = array();

		if ($this->fetchDataModification !== null)
		{
			$modifiers = call_user_func($this->fetchDataModification);

			if (!is_array($modifiers))
			{
				throw new SystemException(sprintf(
					'Fetch Data Modification for %s field of %s entity should return array of modifiers (callbacks)',
					$this->name, $this->entity->getDataClass()
				));
			}

			foreach ($modifiers as $modifier)
			{
				$this->appendFetchDataModifier($modifier);
			}
		}

		foreach ($this->additionalFetchDataModifiers as $modifier)
		{
			$this->appendFetchDataModifier($modifier);
		}
	}

	return $this->fetchDataModifiers;
}