Nullable Dates

In AbleCommerce 7.0.0 through AbleCommerce 7.0.7, many of our objects had DateTime properties that were nullable in the database. In these versions we would translate null into the value System.DateTime.MinValue when reading the records. When making business logic decisions the DateTime property would need to be checked against DateTime.MinValue to see if it was present.

In AbleCommerce Gold the behavior changes slightly. Instead of translating null dates, our DateTime properties are nullable. This means the property can either be null or it can have a value. In order to use these DateTime properties you must be sure to factor in the possibility that the value does not exist in the database. In these cases you must decide how to handle that condition.

A list of the properties that are nullable are below:

CLASS	PROPERTY	SIGNIFICANCE OF NULL
Coupon	StartDate	The coupon has no restriction on when it starts to be valid.
Coupon	EndDate	The coupon has no restriction on when it ceases to be valid.
EmailList	LastSendDate	The email list has never been sent.
EmailListUser	LastSendDate	The email list has never been sent to this list member.
OrderItemDigitalGood	ActivationDate	The digital good has not been activated.
OrderItemDigitalGood	DownloadDate	The digital good has not been downloaded.
OrderShipment	ShipDate	The order shipment has not been shipped.
Subscription	ExpirationDate	The subscription has no expiration.
Payment	CompletedDate	The payment has not yet been completed.
Special	StartDate	The special has no restriction on when it starts to be active.
Special	EndDate	The special has no restriction on when it ceases to be active.
Redirect	LastVisitedDate	The redirect has never been visited.
Currency	LastUpdate	The exchange rate for the currency has never been updated.
User	AffiliateReferralDate	The user has not been referred by an affiliate.
User	LastActivityDate	The user has never browsed the site.
User	LastLoginDate	The user has never logged in.
User	LastPasswordChangedDate	The user has never changed the password.
User	LastLockoutDate	The user has never been locked out.

Working with Nullable Dates

In customizing code with these properties you may notice from Intellisense that nullable dates act a little different from regular DateTime values. There are two different ways to decide if a DateTime has a value:

if (Coupon.StartDate.HasValue)

OR

if (Coupon.StartDate != null)

And when accessing the DateTime you need to use the Value property:

Coupon.StartDate.Value