W3C home > Mailing lists > Public > public-rdfa-wg@w3.org > October 2011

More direct conversion from microdata to RDFa?

From: Stéphane Corlosquet <scorlosquet@gmail.com>
Date: Wed, 12 Oct 2011 10:56:49 -0400
Message-ID: <CAGR+nnF+zQV+UwdAtoeXcU=KK3XJoJDFstx-hWbMzEDkwenVmw@mail.gmail.com>
To: public-rdfa-wg@w3.org
Converting microdata to RDFa could be made easier by bypassing the vocab
attribute. Microdata incorporates the concept of vocabulary in the data item
type via @itemtype. Coming from a microdata perspective, the concept of
vocabulary URI is an extra element (different from the item type) which
could be avoided by the following proposal. Since there is a mechanism being
designed to infer a vocabulary namespace from the microdata @itemtype, RDFa
could use a similar mechanism, and use the first token of @typeof to
construct the namespace that we currently put in @vocab.

Consider the following microdata snippet:

<div itemscope itemtype="http://schema.org/Person>
   My name is <span itemprop="name">John Doe</span>.

Currently to convert to RDFa, you need to split @itemtype into two
attributes: @vocab and @typeof. What I'm suggesting is a direct mapping from
@itemtype to @typeof without the need of @vocab, where @typeof would include
the full URI:

<div typeof="http://schema.org/Person>
   My name is <span property="name">John Doe</span>.

This would ease the RDFa to microdata and vice versa from a human

Note that I'm not suggesting to drop @vocab, but simply to make it optional,
which would make the common microdata snippets a no brainer to convert to
RDFa by a simple attributes string replace. In the processing model
sequence, step 3 would have to include an extra step for the case where
@vocab is missing, and use the same mechanism as Gregg is defining for
microdata to RDF conversion. Here is a suggestion:

3. Next the current element is examined for any change to the default
vocabulary via @vocab. If @vocab is present and contains a value, its value
updates the local default vocabulary. If the value is empty, then the local
default vocabulary must be reset to the Host Language defined default. If
@vocab is not present but the first token of @typeof is an absolute
URI, construct the local default vocabulary by removing everything following
the last SOLIDUS U+002F ("/") or NUMBER SIGN U+0023 ("#") in the first token
of @typeof.


Received on Wednesday, 12 October 2011 14:57:28 UTC

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