Dear Augusto, Sorry for not being clearer, but this discussion has just begin last week at plugfest, and I've sent an email trying to summarize, with a link to my presentation. So let's try to explain my proposals. Unfortunately, there is no perfect format. JSON format is more compact, but some important features are missing in order to use it for a full specification. Utilities (parsers, validators and such) are important for both formats, a little bit less for JSON but growing. IMO, JSON rendering must be defined for its wide use in web applications and some NoSQL storage (Riak...). Nevertheless, XML/XSD has the following advantages for formal specs: - comments included: both formal (appinfo) and informal (annotation) - string typing: 44 base types + extensions/restrictions. About the completness of schemas, I've been asked several times this question, so I think a little bit of clarification is needed: 1/ entities must be validated against their category description: we can use schemas for that, ie each category is described with a schema. In that case, resource validation can be really fast to implement, but there is still no formal way of describing categories (XML schema should be restricted for that), 2/ category description should be validated against a grammar. This category description, then must provide the implementation enough information to validate entities: actually OCCI grammar (for text/occi) is formal but can not embed a lot of semantic about attribute types, attribute multiplicity and such. The goal of my XML representation is to fullfill need of 2/. I make the assumption it is more important to have formal OCCI representation for extensions, and write a little bit of code to achieve 2/ rather than having 1/ done by existing tools (XML validators) but not being able to achieve 2/. Regards, Jean Le 23/09/2013 16:59, Augusto Ciuffoletti a écrit :
I'm not following this group from the very beginning, and I do not remember a discussion about XML as a rendering option.
Maybe Andy or Thijs have a record about this. JSON appears as more compact wrt XML, but probably XML has a richer set of utilities and is overall more established: any other relevant difference? There is an ongoing effort on a JSON rendering.
I think that schemas are unable to capture certain semantic aspects of OCCI specs, so their application, while useful, is not sufficient. Certainly the availability of libraries for navigating complex/deep structures is relevant.
-- Jean Parpaillon Open Source Consultant Phone: +33 6 30 10 92 86 im: jean.parpaillon@gmail.com skype: jean.parpaillon linkedin: http://www.linkedin.com/in/jeanparpaillon/en