Re: [Widgets] Widget Gallery RSS like sharing format

On Wed, Mar 18, 2009 at 9:35 AM, Andrew Welch <andrew.j.welch@gmail.com> wrote:
> 2009/3/17 Robin Berjon <robin@berjon.com>:
>> On Mar 17, 2009, at 13:24 , Marcos Caceres wrote:
>>>
>>> Agreed. Thinking forward, how do you recommend we identify version 2.0
>>> of the widget configuration file format (or should we just cross that
>>> bridge when we get to it?) ?
>>
>> Personally, I would recommend that we don't :) Version identifiers are
>> largely useless and experience shows that users use them wrong (e.g. a bunch
>> of SVG out there that's labelled as 1.1 is really 1.2, but people just
>> copy-paste the root element).
>>
>> There are strategies to implement versioning of XML vocabularies which don't
>> require having a version identifier. These are generally based on an
>> "ignore" approach whereby elements and attributes that the processor doesn't
>> know about are silently skipped. That means we can add new features in the
>> next revision and it won't break older UAs. If at some point we make
>> breaking changes, then we just change the namespace.
>>
>> Note that this needs to be defined in v1, so no, I think we have to cross
>> that bridge now. SVG includes this strategy:
>>
>>  http://www.w3.org/TR/SVGMobile12/implnote.html#UnsupportedProps
>>
>> It is worth pointing out that porting the same strategy to the configuration
>> document would be simpler.
>
> Are you sure changing the namespace is preferable to a version
> attribute?  Seems very drastic, and usually it's best to avoid doing
> it as it makes all tools that process existing markup redundant.
>
> Also, you mention most users "just copy-paste the root element" -
> surely you'd still have the problem if you change the namespace?
>
> At the moment, I don't think there is any establised "right way" when
> versioning xml, but changing the namespace is a bad idea.

I agree. Changing the namespace is a bad idea. I didn't get the sense
that this is what Robin was suggesting, however. From a quick glance
at the SVG link above, I didn't see anything relating to changing the
namespace (though it was a super quick glance, so I might have missed
it!:))

-- 
Marcos Caceres
http://datadriven.com.au

Received on Wednesday, 18 March 2009 08:41:26 UTC