[uf-discuss] mixing vocabularies

[Brian Suda]

On Wed, Jun 24, 2009 at 1:51 PM, Thomas Loertsch<loertsch.thomas at guj.de> wrote:
> hi all,
>
> a question: when contemplating over the feature set of hRecipe it occured to
> me that i don't seem to get the rational of mixing vocabularies in all it's
> subtleties. e.g. why should i add rel-tag to the hRecipe vocabulary when
> people can use rel-tag anyway on any element they want to? likewise for
> author and date.

--- When you have a single vocabulary for all microformats you get the
benefit of calling a URL in hCard the same thing as a URL in
hCalender. If you have an hRecipe on a page with Rel-Tag "cake" that
page is inpart about "cake" so a parser that is extracting Recipes get
the hRecipe and a rel-tag parser gets the tags too. Had hRecipe called
their rel-tags something else, then you´d be doubling-up class values
on tags, one for plain rel-tag and one for the hRecipe. So having just
1 vocabulary means that parses can be aware of the formats they know
and extract them from anywhere in the page, even if they are within
other formats.

> if i understand correctly the way meta information is added to the DOM
> defines which elements are described. when investigating the use of hRecipe
> i often found some top level div containing the recipe marked up with
> classes hRecipe and some other vocabulary e.g. <div id="yet_another_recipe"
> class="hrecipe vcard">. recipe specific elements where then marked up with
> hrecipe vocabulary while the author was marked up as vcard. this seems like
> a sensible approach to me. or does it make the job for parsers much harder?

Now, it makes it easier for parsers. a vCard is a vCard, even if it's
in an hRecipe or standing alone, the semantic data is the same.
Instead or re-inventing the wheel each time, existing formats are
used. Then hCard parsers don't need to be updated to know how to
extract person data out of an hRecipe, etc.

I hope that makes sense. You should add this to the Wiki under the
FAQs, then we can all iterate on the best answer.

-brian

-- 
brian suda
http://suda.co.uk