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[whatwg] adding microdata to basic links

From: Ian Hickson <ian@hixie.ch>
Date: Thu, 8 Dec 2011 22:11:27 +0000 (UTC)
Message-ID: <Pine.LNX.4.64.1112082155370.9078@ps20323.dreamhostps.com>
On Wed, 24 Aug 2011, St?phane Corlosquet wrote:
>
> Starting from a basic markup like this:
> [[[
> This book has been authored by <a href="http://smith.org/john">John
> Smith</a>.
> ]]]
> 
> I would like to markup both the textContent of the link ("John Smith") and
> the url from the href attribute.
> 
> In RDFa this is done by adding a couple of attributes to the a element. It
> would read like this:
> [[[
> This book has been authored by <a property="name" rel="url" href="
> http://smith.org/john">John Smith</a>.
> ]]]
> 
> Is there any way to do the same in microdata without adding a new HTML
> element to the markup?

On Wed, 24 Aug 2011, Tab Atkins Jr. wrote:
> 
> No, Microdata purposely keeps its data model simple by expressing 
> property names through a single attribute.  Since having @itemprop on an 
> <a> always refers to the @href of the element, you must nest an 
> additional element, such as a <span>, into your markup to carry the 
> property that refers to the text content.

Indeed.

The reasoning is that it's hard to understand otherwise; e.g. it's not at 
all immediately obvious to me that this is wrong, though it is:

   <a property="url" href="http://smith.org/john">John Smith</a>

...and while an experienced author would know that "rel" is to "href" as 
"property" is to the contents, an inexperienced one might still make 
mistakes such as:

   <a property="url" href="http://smith.org/john"
      rel="name">John Smith</a>

In microdata, <a> always gives the URL, which simplifies it a bit, at the
cost of making this example more verbose.


On Wed, 24 Aug 2011, Tantek ?~Gelik wrote:
>
> This does seem to be a (fairly common) case where microdata requires 
> additional markup (another element) whereas both microformats (e.g. 
> hCard) and [RDFa] (through the perhaps questionable overloading of 
> 'rel') do not.

Yeah. Microformats 2 has an interesting compromise solution where 
Hungarian notation is used to denote the type of the property, and that 
type is used to determine how it is read. The cost of that of course is 
the slightly more verbose markup in all property names.


On Wed, 24 Aug 2011, St?phane Corlosquet wrote [edited for simplicity]:
>
> [[[
> This book has been authored by
>     <span vocab="http://schema.org/" typeof="Person">
>         <a property="name" rel="url" href="http://smith.org/john">John
> Smith</a>
>     </span>
> ]]]

On Wed, 24 Aug 2011, Edward O'Connor wrote [edited for brevity]:
> 
> This could be represented in Microdata without an extra element:

Well, microdata needs to use an element that is undecorated in the 
original, namely the <p> that I removed in the quote above:

> <p itemscope itemtype="http://schema.org/Person">
>     This book has been authored by
>         <span itemprop="name">
>             <a itemprop="url" href="http://smith.org/john">John
> Smith</a>
>         </span>
> </p>

The microformats for this particular case is shorter still.


I haven't changed microdata for this; the current design is an intentional 
trade-off between verbosity and predictability.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 8 December 2011 14:11:27 UTC

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