RIA Services: How dates are handled and sent across the wire

The current(July) preview of RIA Services handles DateTime objects in an strange manner. Many of silverlight developers have complained in Silverlight forums that their dates are messed up. In this post, I am listing down several observations as a reference. Note that my current settings are +6 GMT.

From 	DateTime.Kind 	 DateTime.Value        To     DateTime.Kind  DateTime.Value
---- 	-------------   ----------------       --     -------------  ---------------
Client 	Unspecified     2009-01-01 00:00     Server 	Utc         2008-12-31 18:00
Server 	Unspecified     2009-01-01 00:00     Client 	Utc         2008-12-31 18:00
Client 	Local 	        2009-01-01 00:00     Server 	Utc         2008-12-31 18:00
Server 	Local 	        2009-01-01 00:00     Client 	Utc         2008-12-31 18:00
Client 	Utc 	        2009-01-01 00:00     Server 	Utc         2009-01-01 00:00
Server 	Utc 	        2009-01-01 00:00     Client 	Utc         2009-01-01 00:00

We can see that whatever Datetime we send, RIA service converts it to UTC when received at the other end. This could be bearable up to some extent but the worst thing is that RIA domain service treats Unspecified dates as Local and performs respective time zone conversion. Also, there is a UsesUtcDateTimes overridable in DomainService class but currently it does not seem to produce any effect.

Notice that there is no such conversion when using a WCF service, so whatever datetime value and kind we send from one side is exactlyreceived the same at the other side.

Lets hope the issues are fixed in the next version of RIA services.

My sample application that I used to test the behavior of RIA Domain Service and WCF Service can be downloaded from here. Remember to rename it to .zip for extraction.

RIA Services: Working with Foreign Keys/Associations in Entity Framework

Yesterday, I got an strange observation regarding RIA Services. I needed to created an Entity Model from views instead of tables so it had no foreign key associations defined. I manually created the associations and was finally able to get a working model. I then added a RIA Domain Service and got the following error upon build:

“Unable to retrieve AssociationType for association ‘JobWBS_ResourceAssignment’”

Strange. But after some effort I came to know that the current(July 2009) preview of RIA services expects all the associations in the default foreign key naming convention, i.e., FK_ForeignKeyTable_PrimaryKeyTable. In my case, I had a 1-Many relationship between JobWBS and ResourceAssignment so I changed the association name to FK_ResourceAssignment_JobWBS and the project built successfully.

Update: If you are still not able to get rid of the error. Its probably because your SSDL schema does not have the proper associations defined. Have a look at this post on how to manually define associations in the physical (storage) model.