[uf-discuss] mixing vocabularies

[Peter Mika]

Unfortunately, the combination of microformats is not as simple issue as 
it seems. I know that certain combinations are explicitly sanctioned by 
the specifications, but the users are trying all kinds of combinations 
that are not explicitly forbidden, but lead to confusion on the part of 
whoever needs to parse it.

Look at for example at [1]. This page contains the following markup:

<table class="infobox infobox vcard vevent" cellspacing="5" 
style="width: 22em; text-align: left; font-size: 88%; line-height: 
1.5em; font-size:90%; text-align:left;">
<tr>
<td colspan="2" class="fn summary" style="text-align:center; font-size: 
125%; font-weight: bold; font-size:110%; background:khaki;">Kevin Bacon</td>
</tr>

If I look at it strictly, I have a vcard and an event object which both 
have the name "Kevin Bacon". However, what the author intended is 
probably a person object, with some terms borrowed from vevent (not sure 
which ones).

So what do you guys think about this? Note that on our side this 
introduces the secondary problem that we now have to figure which object 
is the main topic of the page (it's very clear for the human!)

Thanks,
Peter

[1] http://www.answers.com/topic/kevin-bacon


Brian Suda wrote:
> 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
>
>