Base::getValue

static function getValue(array $input, $value)
{
	if (isset($input['DISABLED']) && $input['DISABLED'] === 'Y')
	{
		return null; // TODO maybe??
	}

	if ($value === null)
	{
		$value = $input['VALUE'] ?? null;
	}

	if (isset($input['MULTIPLE']) && $input['MULTIPLE'] === 'Y')
	{
		$values = array();

		foreach (static::asMultiple($value) as $value)
		{
			$value = static::getValueSingle($input, $value);
			if ($value !== null)
				$values []= $value;
		}

		return $values ? $values : null;
	}
	else
	{
		return static::getValueSingle($input, static::asSingle($value));
	}
}