Hi Udayanga, udayanga wickramasinghe <[email protected]> wrote on 03/23/2010 08:53:14 AM:
> Hi Michael, > Thnx for your helpful feedback on Xerces projects available. Yes i > do went through Apache proposed projects list under Xerces (i was > frankly surprised to see SCD this year as well...thought it was > completed in last year's GSoc) , and wanted to know if there are > some additional ideas you might have , since most f the proposed > project appeared to have been undertaken. Certainly doesn't have to be limited to what's been posted so far. I can think of at least a few other areas (e.g. xml:id [1] and StAX serialization) which haven't been tackled yet and possibly other feature requests that have been made over the years that are still active in JIRA. You're also welcome to come up with your own ideas. > I think Ishan plans to do the part ,the derivation of a canonical > SCP , given a shemaComponent,Namespace ctxt and the corresponding > XSModel . (If you go through his recent posts , he has already > defined #getCanonicalSCP(XSObject, > XSModel,NamespaceContext) under the set of interfaces he's going to > implement) .I'm just curious as to how exactly it's going to be > worked out...since it's the reverse problem of resolving a SCP > expression (which IMHO is a bit straightfoward than deriving a SCP > for a scehma component) , can there be a 1:n correspondence? ie:- > for a respective schema component on a given XSModel is there a > possibility for several SCP expressions existing?? The canonical path is supposed to uniquely identify the schema component so there should be only one such expression. > Btw among the ideas you have mentioned, i'm interested in the > implementation of XML Schema 1.1.spec , xs:override(http:// > www.w3.org/TR/xmlschema11-1/#override-schema). I find it to be very > interesting and would indeed be a useful addition for Xerces as well. I would > very much appreciate if you could please further elaborate on the > project requirement..ie:- the scope , technical challenges, related > work that might be useful(i see it is a bit similar to > xs:redefine..) ,etc , so that i would be able to get a much clear > idea n get things started.Thnx in advance.... Yes, xs:override is similar to xs:redefine except that it allows unconstrained replacement of schema components. Given the problems implementers and users of XML Schema have had with xs:redefine I would expect that once it's available that it would become the recommended way to replace schema components. The scope of the project would be to implement this feature. There's a discussion [2] from last year that you may find helpful, particularly the response from Khaled Noaman on the challenges of implementing xs:override. Hiranya [3] (his patch is for a much earlier XML Schema 1.1 draft; the spec has changed quite a bit since then so would no longer apply), Mukul and Khaled have looked at this before but I don't believe anyone has been working on an implementation lately. I believe most of the work still needs to be done. We would welcome the help. > -Udayanga Thanks. [1] https://issues.apache.org/jira/browse/XERCESJ-1113 [2] http://markmail.org/thread/tv3qtoofzya4ts7l [3] https://issues.apache.org/jira/browse/XERCESJ-1341 Michael Glavassevich XML Parser Development IBM Toronto Lab E-mail: [email protected] E-mail: [email protected]
