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Re: Syntax for itemprop breadcrumb

From: Aaron Bradley <aaranged@yahoo.com>
Date: Sat, 17 Dec 2011 11:23:31 -0800 (PST)
Message-ID: <1324149811.99301.YahooMailNeo@web161003.mail.bf1.yahoo.com>
To: Jason Douglas <jasondouglas@google.com>, Gregg Kellogg <gregg@kellogg-assoc.com>
Cc: John Panzer <jpanzer@google.com>, Jeni Tennison <jeni@jenitennison.com>, public-vocabs <public-vocabs@w3.org>, Tim van Oostrom <tim@depulz.nl>


Thanks everyone for weighing in on this.

I was surprised to see John Panzer's parser results supporting Jeni Tennison's option C - "the examples are wrong and the itemprop should be on individual breadcrumb items" - not because it doesn't make sense, but that the examples are consistently wrong across the board in regard to schema.org microdata.

I checked on the main Google Breadcrumb article...
http://support.google.com/webmasters/bin/answer.py?hl=en&answer=185417
... and discovered there that, indeed, breadcrumbs are marked up individually, both in RDFa and for (data-vocabulary.org) microdata.

A snippet of their microdata example:
<div itemscope itemtype="http://data-vocabulary.org/Breadcrumb";>
  <a href="http://www.example.com/dresses"; itemprop="url">
    <span itemprop="title">Dresses</span>
  </a> ›
</div>  
<div itemscope itemtype="http://data-vocabulary.org/Breadcrumb";>
  <a href="http://www.example.com/dresses/real"; itemprop="url">
    <span itemprop="title">Real Dresses</span>
  </a> ›
</div>

A friend weighed in on my G+ thread with an observation very similar to yours, Jeni:
"Well.. if you read the specification the Expected Type for "breadcrumb" is text, so it doesn't really matter if its a link or not. Semantically, a breadcrumb is really only a category marker and it shouldn't matter if its a link or not. In modern uses, it is hyperlinked for usability, but technically, it doesn't need to be linked for a human or bot to parse out the categorization structure."

So my takeaways are two-fold:

1.  The schema.org examples are incorrect, and each individual breadcrumb should be declared with itemprop.
2.  While schema.org describes the breadcrumb property as "[a] set of links" the expected property is text rather than URL, which at least technically affirms that breadcrumbs need not be links.

Thanks!

>________________________________
> From: Jason Douglas <jasondouglas@google.com>
>To: Gregg Kellogg <gregg@kellogg-assoc.com> 
>Cc: John Panzer <jpanzer@google.com>; Jeni Tennison <jeni@jenitennison.com>; public-vocabs <public-vocabs@w3.org>; Tim van Oostrom <tim@depulz.nl>; Aaron Bradley <aaranged@yahoo.com> 
>Sent: Saturday, December 17, 2011 10:18:36 AM
>Subject: Re: Syntax for itemprop breadcrumb
> 
>
>On Sat, Dec 17, 2011 at 9:00 AM, Gregg Kellogg <gregg@kellogg-assoc.com> wrote:
>
>Interesting that this is one place where RDFa @rel does what you want. 
>
>
>I was under the impression @rel was still allowed in RDFa Lite, just not required.  Named links seems like a use case where it does make things simpler.
>
> 
>It also requires @inlist to maintain the breadcrumb order.
>>
>>
>>RDFa Lite will have the same restrictions as microdata, requiring a @property on each <a> and depend on the vocabulary-specific handling of schema:breadcrumb to maintain order in RDF.
>>
>>Gregg Kellogg
>>Sent from my iPhone
>>
>>On Dec 17, 2011, at 7:43 AM, "John Panzer" <jpanzer@google.com> wrote:
>>
>>
>>For my parser, (c) appears to be the answer today.
>>>On Dec 17, 2011 12:30 AM, "Jeni Tennison" <jeni@jenitennison.com> wrote:
>>>
>>>Hi,
>>>>
>>>>Just to point out that in something like:
>>>>
>>>><div itemprop="breadcrumb">
>>>> <a href="category/books.html">Books</a> >
>>>> <a href="category/books-literature.html">Literature & Fiction</a> >
>>>> <a href="category/books-classics">Classics</a>
>>>></div>
>>>>
>>>>the 'breadcrumb' property actually takes the value "Books > Literature & Fiction > Classics" (whitespace normalised for brevity). So whether or not they have <a> elements wrapped around individual words doesn't matter: a conformant microdata processor won't see them anyway.
>>>>
>>>>I've raised this before, but it is still not clear to me whether
>>>>
>>>>a. schema.org consumers only want that plain text string;
>>>>b. schema.org consumers are preserving the HTML content (contrary to the microdata spec); or
>>>>c. the examples are wrong and the itemprop should be on individual breadcrumb items
>>>>
>>>>Cheers,
>>>>
>>>>Jeni
>>>>
>>>>On 16 Dec 2011, at 23:30, Aaron Bradley wrote:
>>>>
>>>>>
>>>>>
>>>>> Thanks for weighing in, Tom.
>>>>>
>>>>> In this case, though, all the examples explicitly show all breadcrumb links belonging to one itemprop - what they omit is an additional, unlinked "breadcrumb" component.
>>>>>
>>>>> See on http://schema.org/WebPage:
>>>>>
>>>>> <div itemprop="breadcrumb">
>>>>>   <a href="category/books.html">Books</a> >
>>>>>   <a href="category/books-literature.html">Literature & Fiction</a> >
>>>>>   <a href="category/books-classics">Classics</a>
>>>>> </div>
>>>>>
>>>>>
>>>>> By the way, the separate page identifier in the <h1> I wouldn't have a problem handling (it's not a breadcrumb) - it's the additional component on the same line.  E.g. (and this is the syntax I'm leaning towards - *not* including the unlinked item in the breadcrumb declaration):
>>>>>
>>>>>
>>>>> <div>
>>>>>
>>>>> <span itemprop="breadcrumb">
>>>>>   <a href="category/books.html">Books</a> >
>>>>>   <a href="category/books-literature.html">Literature & Fiction</a> >
>>>>>   <a href="category/books-classics">Classics</a></span> >
>>>>>   Boring Classics
>>>>> </div>
>>>>> <h1>Boring Classics</h1>
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>>> From: Tim van Oostrom <tim@depulz.nl>
>>>>>> To: public-vocabs@w3.org
>>>>>> Cc:
>>>>>> Sent: Friday, December 16, 2011 2:26:37 PM
>>>>>> Subject: Re: Syntax for itemprop breadcrumb
>>>>>>
>>>>>> Hi Aaron,
>>>>>> I personally interpreted breadcrumb like:
>>>>>>
>>>>>> <div itemscope itemtype="http://schema.org/Thing";;>
>>>>>>    <a href="category/books.html"
>>>>>> itemprop="breadcrumb">Books</a>  >
>>>>>>    <a href="category/books-literature.html"
>>>>>> itemprop="breadcrumb">Literature&  Fiction</a>  >
>>>>>>    <a href="category/books-classics"
>>>>>> itemprop="breadcrumb">Classics</a>  >
>>>>>>    Boring Classics
>>>>>> <h1 itemprop="name">Boring Classics</h1>
>>>>>>   </div>
>>>>>>
>>>>>>
>>>>>> 1 breadcrumb per Item/Link (semantically more obvious and less work to
>>>>>> determine what is what?)
>>>>>>
>>>>>> You'd have a list of breadcrumb(s). This should however be an ordered list.
>>>>>>
>>>>>> - Tim
>>>>>>
>>>>>>>   In breadcrumb display, the unlinked current page or section is often
>>>>>> displayed in the same line as the linked parents.  E.g.:
>>>>>>>
>>>>>>>   <div><a href="/">Home</a>  | About
>>>>>> us</div>
>>>>>>>
>>>>>>>   Should this unlinked portion be ("About us" in the example above)
>>>>>> be included in the breadcrumb itemprop or excluded from it? 1 or 2 below?
>>>>>>>
>>>>>>>
>>>>>>>   1 - Unlinked portion part of breadcrumb itemprop
>>>>>>>
>>>>>>>   <div itemprop="breadcrumb">
>>>>>>>     <a href="category/books.html">Books</a>  >
>>>>>>>     <a
>>>>>> href="category/books-literature.html">Literature&
>>>>>> Fiction</a>  >
>>>>>>>     <a href="category/books-classics">Classics</a>
>>>>>>>
>>>>>>>     Boring Classics
>>>>>>>   </div>
>>>>>>>
>>>>>>>   2 - Unlinked portion not a part of breadcrumb itemprop
>>>>>>>
>>>>>>>   <div>
>>>>>>>   <span itemprop="breadcrumb">
>>>>>>>     <a href="category/books.html">Books</a>  >
>>>>>>>     <a
>>>>>> href="category/books-literature.html">Literature&
>>>>>> Fiction</a>  >
>>>>>>>     <a
>>>>>> href="category/books-classics">Classics</a></span>
>>>>>>>
>>>>>>>     Boring Classics
>>>>>>>   </div>
>>>>>>>
>>>>>>>   None of the schema.org examples show this use case.
>>>>>>>
>>>>>>>   See also this same question on a G+ post - feel free to comment there.
>>>>>>>   https://plus.google.com/106943062990152739506/posts/Bf5ZYWkVtM1
>>>>>>>
>>>>>>>   Thanks,
>>>>>>>   Aaron
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>--
>>>>Jeni Tennison
>>>>http://www.jenitennison.com
>>>>
>>>>
>>>>
>
>
>
Received on Saturday, 17 December 2011 19:23:59 UTC

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