Andreas Hartmann wrote: > Hi Jörn, > > IMO the problem about this schema is that it is not generic, > i.e. it is not possible to add custom meta data sets without > changing the schema.
that's a feature. > Additionally, if you convert meta data > to elements, you have to make assumptions, e.g. regarding the > internal storage of workflow versions. This is a concern of > the workflow engine, the meta data component may only read or > write the meta data but not try to parse or understand them. > > > I'd prefer something like this: > > <meta-data xmlns="http://apache.org/lenya/...";> > > <elements namespace="..."> > <element name="foo"> > <value>hello</value> > <value>world</value> > </element> > ... > </elements> > > ... > > </meta-data> > > > I understand that this is not as good as your suggestion when > it comes to validation, but IMO we have to use a really extensible > and generic format to render meta data as XML. depends on what you want. i intended the grammar to be fixed and non-extensible wrt core metadata, so that it really hurts to introduce changes :) moreover, the more detailed and less flexible a grammar is, the better it is for documentation. ultimately, the most flexible solution is <define name="everythingandthekitchensink"> <element> <nsName/> <zeroOrMore> <attribute> <anyName/> <optional> <text/> </optional> </attribute> </zeroOrMore> <interleave> <optional> <text/> </optional> <optional> <ref name="everythingandthekitchensink"/> </optional> </interleave> </element> </define> <start> <ref name="everythingandthekitchensink"/> </start> ;) SoC at its very best, and totally useless for both validation *and* documentation. incidentally, it pretty much reflects the current state, except that it is hierarchic :-D my suggestion is extensible, but it requires an element hierarchy for that - as you said, that's not desirable for internal representation. so how about this: we define a grammar that can contain some fixed lenya-internal metadata items from a special namespace "lenya-meta:". these are validatated in a very thorough way, and must be represented 1:1 in the grammar, leading to a well-defined api and good documentation. at the same time, the grammar can contain arbitrary elements from other namespaces, where people can dump their custom stuff. -- "Án nýrra verka, án nútimans, hættir fortíðin að vekja áhuga." "Without new works, without the present the past will cease to be of interest." - Ásmundur Sveinsson (1893-1982) -- Jörn Nettingsmeier, EDV-Administrator Institut für Politikwissenschaft Universität Duisburg-Essen, Standort Duisburg Mail: [EMAIL PROTECTED], Telefon: 0203/379-2736 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
