DiscountCouponsManagerBase::isExist

static function isExist($coupon)
{
	$coupon = trim((string)$coupon);
	if ($coupon === '')
		return false;

	self::initUseDiscount();
	$couponIterator = InternalsDiscountCouponTable::getList(array(
		'select' => array('ID', 'COUPON'),
		'filter' => array('=COUPON' => $coupon)
	));
	if ($existCoupon = $couponIterator->fetch())
	{
		return array(
			'ID' => $existCoupon['ID'],
			'COUPON' => $existCoupon['COUPON'],
			'MODULE' => 'sale',
			'MODULE_ID' => 'sale',
		);
	}
	else
	{
		if (!self::$onlySaleDiscount && !empty(self::$couponProviders))
		{
			foreach (self::$couponProviders as $provider)
			{
				$existCoupon = call_user_func_array(
					$provider['isExist'],
					array(
						$coupon
					)
				);
				if (!empty($existCoupon) && is_array($existCoupon))
				{
					if (!isset($existCoupon['ID']) || !isset($existCoupon['COUPON']))
						continue;
					return array(
						'ID' => $existCoupon['ID'],
						'COUPON' => $existCoupon['COUPON'],
						'MODULE' => $provider['module'],
						'MODULE_ID' => $provider['module']
					);
				}
			}
			unset($provider);
		}
	}
	return false;
}