Glad to see progress on this. Ray, did anything come out of discussions at Google I/O?
There seems to be two schools of thought here (both equally valid approaches mind you): 1. Help the client participate in the persistence, maintain detached state, dirty field lists, etc. This seems lofty and makes me more concerned about tight coupling, but is probably exactly what is needed for some applications. 2. Make a clean cut and keep the client free from persistence concerns. This could be RPC with seperate DTOs or marshalled XML/JSON. The client is only able to save by sending the modified object which is then fully updated in the database (all fields, since we lost track of what changed). This would typically happen by having the server reconstruct the object (unmarshal), then merge this over an existing entity. Our app actually functions as #2. Currently we use GWT-generated XML conversion code on the client. It's inefficient if your entity has many fields and you change just one. We've employed "sparse xml" to help, where we send back only the elements we want to modify (all of them are optional). When this is applied to the entity, only one field is triggered in the update. In theory this is great but I haven't implemented to dirty field tracking in the client, so in practice we serialize the whole object and we don't get any benefit from it. So I guess I'm sort of sitting on fence on this one. I beleive #1 can work, but I need to see proof of it in a large-ish app before we go and touch anything. On May 30, 4:24 pm, Piotr Jaroszyński <p.jaroszyn...@gmail.com> wrote: > Hey Ray, > > > I've pretty much decided to go the DTO approach at this point as it is > > known to work 100%. I don't feel the current hacks are production > > worthy. > > You have mentioned on your blog that you use protobufs for DTOs. Could > you please elaborate on that? > > P.S. Can't wait for gwt sessions to be uploaded on youtube! > > -- > Best Regards, > Piotr Jaroszyński --~--~---------~--~----~------------~-------~--~----~ http://groups.google.com/group/Google-Web-Toolkit-Contributors -~----------~----~----~----~------~----~------~--~---
