On Fri, Feb 27, 2009 at 9:18 AM, Raymond Feng <[email protected]> wrote: > Hi, > > Please see my comments inline. > > Thanks, > Raymond > From: Simon Laws > Sent: Friday, February 27, 2009 6:16 AM > To: tuscany-dev > Subject: [2.x] [DISCUSS] Backward compatibility > We recently moved over to the OASIS package names [1] and I notice commits > to change the schema yesterday. So I want to discuss the backward > compatibility issue again. If we have aspirations to support any kind of > backward compatibility then we need to think about it now a bit otherwise > we'll make life difficult for ourselves later on > > So what does backward compatibility mean? There are a range of answers. For > example, > > A/ None - SCA 1.0 and SCA 1.1 composites must run on completely separate 1.x > and 2.x Tuscany runtimes. Any interaction is through remote bindings > B/ Shared domain - SCA 1.0 and SCA 1.1 composites can be contributed to the > same domain but spec specific node/runtimes are required to actually run > them. Binding. sca is compatible though. > C/ Shared runtime - SCA 1.0 and SCA 1.1 composites can be contributed to the > same node/untimes > > <rfeng>Good list. There are two primary concerns: XML compatibility and Java > API/Annotation compatibility. XML translation might be much simpler than the > Java API/Annotation. Maybe we should start with XML compatibility > first.</rfeng> > > In my opinion we should do at least B and give some though to the > implications of C to either discount it or address it. > > I think the implication of B is that the assembly model is shared between > SCA 1.0 and SCA 1.1. I don't want to blow progress of course and I still > agree with Ant that we can bring backward compatibility on line a little > later. However if we do just rip and replace SCA 1.0 for SCA 1.1 then it > makes this later effort more difficult that it need be. > > <rfeng>We should have one java model which should be based on OASIS specs. > Then we can see if we can translate the OSOA XML into the OASIS model by the > legacy processors. I don't think the infosets for the two models are > completely compatible. We'll probably see cases that we cannot parse the > OSOA XML into the OASIS model. I more view this as a best-effort.<rfeng> > > This probably just comes down to simple things. It's tempting to just > replace all the xsd's and fix up the processors to take account of them. But > unless we change the processor package names and/or class names then it > makes it harder to bring the SCA1.1 processors back in when we want to run > both in the domain. > > <rfeng>I would rather keep both OSOA and OASIS XSDs. One thing we can do is > to keep a copy of the OSOA-based processors into a different package name > with osoa. </rfeng> > > Thoughts? >
So, trying to summarize the decisions items here : - Have one model, and this one is going to be based on OASIS spec. - Have two processors for each extension, one handling OSOA composites and the other handling OSOA; but both are going to produce OASIS modules. Some more related action items - Start to have two versions of Tuscany NS, 1.0 and 1.1 - Separate 1.0 and 1.1 schemas into separate folders (sca10 and sca11). Note that Tuscany extensions will have two versions of XSD, one using Tuscany 1.0 NS and the other using 1.1 Tuscany NS Some other questions How to handle validation ? Are we going to apply only OASIS assertions, even to OSOA based composite ? Are there any compliance implications here ? What do we do with OSOA based composites that cannot be mapped to OASIS Java Model ? Should we reject it ? > Regards > > Simon > > [1] http://www.mail-archive.com/[email protected]/msg04724.html > -- Luciano Resende Apache Tuscany, Apache PhotArk http://people.apache.org/~lresende http://lresende.blogspot.com/
