Proxy was a raw idea. Physically separating non-object parts of Cayenne from "business" objects and associated business logic is still very appealing. This is about encapsulating ~60-70% of Cayenne stack (mapping model, SQL query translation, caching, etc.) into a web service with clear simple interface. The public API of the proxy will be (serialized) objects though (JSON, protobuf). So that's your generic ORM in a box, serving your object model, but free from your application java dependencies. So the consumers will need to do no ORM translation.
Anyways, I need to sit on this for some time. I feel there's something there in this approach. This is a solution for something, but not for the problem at hand :) Protocol on the other hand (in a Hessian-free future) will likely be the same for both "proxy" and "ROP" designs. So I am more interested in the protocol right now. Andrus > On Dec 14, 2015, at 1:05 PM, Aristedes Maniatis <a...@maniatis.org> wrote: > > On 14/12/2015 6:56pm, Andrus Adamchik wrote: >> For technologies like Swift that don't have native drivers yet it provides >> JDBC driver. > > Even Swift already has native database drivers, according to my quick search > of github. > > > On 14/12/2015 7:00pm, Andrus Adamchik wrote: >> Though I guess the main motivation for Java ROP now is the ability to run >> code both on the client and on the server, right? > > > Absolutely. Lifecycle events are important so that the server doesn't have to > trust the client to perform validation and authorisation, and also trigger > other processes like audit trails. > > Also important are clever query concepts like pagination and prefetches. > > What could be better is integrated support for distributed caches and cache > invalidation. Or at least the hooks to make it easier to leverage > ActiveMQ/EHCache/etc as a way to do these things. > > > > On 14/12/2015 7:18pm, Andrus Adamchik wrote: >> Another thing that I hoped to achieve in Cayenne is seamless >> reverse-engineering flow. The biggest hurdle in ORM is the constant need to >> sync up multiple layers: DB -> ORM -> code. Annotation-based frameworks >> combine ORM with code, somewhat easing the pain (though making things dirty >> in the process). Our full separation of all 3 layers always seemed right. >> But now I think of it as an advantage not being utilized. > > > I guess I'm not seeing that pain. I really should get around to cleaning up > and contributing my cgen plugin for gradle, but really this should all be > automated by the build tool. > > Perhaps we should work on some liquibase integration to help with the > database update process. We do this by hand, but it would be nice for cgen to > detect the changes and append a liquibase XML snippet. > > >> So the hope is that we can do better, and perhaps a zero-manitenance proxy >> is the answer to the sync problem as well. But maybe I am on the wrong track >> completely by mixing modeling and query execution aspects here. >> >> Anyways, just thinking out loud :) > > > If a proxy layer doesn't let you run code, then what does it do? You have > Hessian serialisation instead of SQL serialisation. You have HTTP instead of > JDBC. But then what? > > Certainly the limitation of ROP is that the client is currently limited to > Java, which means roughly Swing/JavaFX. Opening it up to other UI choices > means porting a great part of Cayenne (all the client bits are still quite a > lot) to Swift or Android or .NET or something. But (to bring this back on > topic) protobuf does help there since the client and server can be different > languages. > > > Ari > > > -- > --------------------------> > Aristedes Maniatis > GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A
