On 4/11/06, Andrew Miller <ak.miller@auckland.ac.nz> wrote:
I think that support for each individual version of CellML is quite independent.
That wasn't the impression I got from your other message, because you said; "I am not aware of anyone supporting 1.1 and not going to the extra effort to support 1.0." You did add though, "However, this may not continue for future versions." but I don't see why that would be the case. Don't get me wrong, it's a fine goal, but IME, it happens only when the design of the format explicitly supports it, and AFAICT, CellML doesn't (more below) [...]
I think that it would give software a lot more flexibility if there was either a version parameter, or a media type. This would allow scripts which serve CellML documents over HTTP to use content-type negotiation to determine which version of the CellML document to send. For example, a client might send
GET /models/SomeModel.xml HTTP/1.1 Host: www.example.org Accept: application/cellml-1.0+xml; q=0.5, application/cellml-1.1+xml; q=1
CellML is 2.5 years old. And since, AFAICT, there's no existing CellML media types, I presume this kind of negotiation doesn't happen already? Do you have any reason to believe it would occur if separate media types were registered? Earlier you wrote;
There are no drafts of future versions at the moment, but it is likely that they will add features which mean that CellML 1.0 and CellML 1.1 processing software cannot reliably utilise documents encoded in them.
I would expect that wasn't necessarily the case. Does it not depend on the feature? I would think that there are probably features which can be added in such a way that it's safe for processors which don't recognize them to simply ignore them (so called "must ignore" rule), no? This is how extensibility is typically managed on the Internet and the Web; by designing formats which can accomodate some kinds of extensions in order to enable a more graceful rollout, i.e. not requiring simultaneous software upgrades. I would strongly recommend that you consider this approach for the next version of CellML. In the meantime though, I still think a single media type is your best bet based on the information you've provided us. Cheers, Mark. -- Mark Baker. Ottawa, Ontario, CANADA. http://www.markbaker.ca