Validate before a save

By default DevForce validates every entity on the server before saving it. This behavior can be modified by overriding the ValidateSave method in a custom EntityServerSaveInterceptor.

Client side validation is not performed automatically but can be easily accomplished via the EntityManager.Saving event.  

Handling validation errors

If any validation errors are encountered on the server, there are two mechanisms by which these errors are reported back to the EntityManager that performed the save. 

• Any errors will be propagated back to the "errant" entities within the calling EntityManager's cache and each of these entities will have its EntityAspect.ValidationErrors property automatically updated. Providing that these entities have been 'bound' to a client side UI and because of the eventing behavior provided by the ValidationErrors property and DevForce's implementation of the INotifyDataErrorInfo and IDataErrorInfo interfaces; these errors should appear immediately in the client side UI.
• The EntityManagerSaveException.EntitiesWithErrors property of the EntityManagerSaveException reported by the EntityManager.Saved event and the EntitySaveOperation.Completed  event, if the save call was asynchronous, will both contain these 'errant entities'.

Any errors encountered can then be 'fixed' and the same save resubmitted again.