[whatwg] Microdata feedback

Philip Jägenstedt philipj at opera.com
Tue Jul 12 07:17:17 PDT 2011

On Tue, 12 Jul 2011 09:41:18 +0200, Henri Sivonen <hsivonen at iki.fi> wrote:

> On Thu, 2011-07-07 at 22:33 +0000, Ian Hickson wrote:
>> The JSON algorithm now ends the crawl when it hits a loop, and replaces
>> the offending duplicate item with the string "ERROR".
>> The RDF algorithm preserves the loops, since doing so is possible with
>> RDF. Turns out the algorithm almost did this already, looks like it was  
>> an
>> oversight.
> It seems to me that this approach creates an incentive for people who
> want to do RDFesque things to publish deliberately non-conforming
> microdata content that works the way they want for RDF-based consumers
> but breaks for non-RDF consumers. If such content abounds and non-RDF
> consumers are forced to support loopiness but extending the JSON
> conversion algorithm in ad hoc ways, part of the benefit of microdata
> over RDFa (treeness) is destroyed and the benefit of being well-defined
> would be destroyed, too, for non-RDF consumption cases.

I don't have a strong opinion, but note that even before this change the  
algorithm produced a non-tree for the "Avenue Q" example [1] where the  
"adr" property is shared between two items using itemref. (In JSON, it is  
flattened.) If we want to ensure that RDF consumers don't depend on  
non-treeness, then this should change as well.


Philip Jägenstedt
Core Developer
Opera Software

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