John Rayner a écrit : > If your domain aggregates are reasonably well-defined, you can keep > track of the size of the WCF payload. Personally, I have no big > problem giving read-only access directly onto entities, although I > shudder at the thought of taking update messages in this fashion (i.e. > simply persisting a desrialized object). My project exposes entities > from read access and uses separate command objects for insert / update > actions. > > OTOH exposing domain objects doesn't give you the ability to have > multiple "views" of the same object, e.g. a small class containing > basic person details, and a larger class containing their full > profile. Using entities + DTOs means that you can use the same entity > and map onto a different DTO for serialization. Exposing entities > directly means that you need to create multiple entity classes (e.g. > PersonSummary and Person). This can feel a little bit odd, but IMO > it's manageable. I imagine that DDD purists would tell me that this > is just wrong! :-) > > Cheers, > John > > On Jan 30, 8:03 pm, Eric Hauser <[email protected]> wrote: > >> The biggest pitfall to consider is how much data will be serialized >> when you expose your entities over WCF. For instance, you can map a >> collection that may be very large on an object and if you are not lazy >> loading, all of that data will be serialized over the web service. >> >> The answer really is "it depends", but assuming this is an large >> project, I always consider my web service contracts to be data >> transfer objects. Explicitly copy the data from the entities onto the >> contract. It is best to think of web service objects as messages and >> not entities. There should be a decent amount of information on this >> subject if you do some searching. >> >> > > > > > > I quite agree with you. You can take advantage using DTO.
One of the top advantage, is that with do not have a strong correlation between persistence and business. Most of the developper appreciate this separation of concerns, and it gives us more control over the database. And the same way, you can re-use entities, stop thinking in terms of database. DTO are not that bad. fred --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nhusers?hl=en -~----------~----~----~----~------~----~------~--~---
