GWT RequestFactory and multiple types

Question

My GWT app has ten different kinds of entities. Right now I use plain old DTOs and transport them over GWT-RPC. This works well for cases like startup - I can pack them all into a single request.

I'm looking at switching to RequestFactory because there are many times throughout the lifetime of the app (30 minutes, on average) when I just have to update one type of entity, and the unifying/bandwidth-saving features of RequestFactory are appealing. BUT: I don't see a way to download all of my initialization data in a single request when the app loads. I don't want to have to make ten requests to fetch all of the init data for my ten entity types.

Is there a way to make a GeneralRequestContext, or something? I'd even be happy with a solution like:

public interface InitDataProxy extends EntityProxy
{
    public UserProxy getInitUsers();
    public OrganizationProxy getInitOrganizations();
    ...
}

public interface GeneralRequestContext extends RequestContext
{
    Request<InitDataProxy> getInitData();
}

But this won't work because I don't want to have to actually back InitDataProxy with anything, I just want to use it to combine a bunch of different types of Proxies in a single request.

So: Is there a way to receive multiple, unrelated types of EntityProxy in a single request?

I would also be happy enough making a normal gwt-rpc request to go outside of RequestFactory for this data, but I don't want to have to implement duplicate DTOs to run next to RequestFactory's proxies, and write custom code to copy the DTOs into them!

Answer 1

The InitDataProxy could extend ValueProxy instead, which doesn't require that the object on the server have any kind of id or version semantics. The domain-side InitData type could be an interface, possibly implemented with an anonymous type.

interface InitData {
  User getUser();
  Organization getOrgatization();
}
class InitService {
  static InitData makeInitData() {
    return new InitData() { ..... };
  }
}

@ProxyFor(InitData.class)
interface InitDataProxy extends ValueProxy {
  UserProxy getUser();
  OrganizationProxy getOrganization();
}
@Service(InitService.class)
interface Init extends RequestContext {
  Request<InitDataProxy> makeInitData();
}