Re: ISSUE-41: Facebook open graph protocol

On 04/22/2010 03:31 PM, Maciej Stachowiak wrote:
>
> On Apr 22, 2010, at 12:28 PM, Philippe Le Hegaret wrote:
>
>> Facebook announced yesterday support for the open graph protocol [1]. It
>> allows website to integrate themselves into the facebook social graph.
>> They already have several partners that are going to deploy that with
>> them.
>>
>> Their system is based on RDFa, and thus using xmlns attributes:
>> [[
>> <html xmlns:og="http://opengraphprotocol.org/schema/"
>> xmlns:fb="http://developers.facebook.com/schema/">
>> <head>
>> <title>The Rock (1996)</title>
>> <meta property="og:title" content="The Rock" />
>> <meta property="og:type" content="movie" />
>> <meta property="og:url"
>> content="http://www.imdb.com/title/tt0117500/ "/>
>> <meta property="og:image"
>> content="http://ia.media-imdb.com/rock.jpg" />
>> ]]
>>
>> They're using XHTML 1.0 with the media type text/html. I don't think
>> they're going to switch to application/xhtml+xml soon.
>>
>> Effectively, from a technical perspective, it's a great news for the
>> RDFa community. But, from the point of HTML, Facebook and their partners
>> are deploying xmlns attributes in HTML all over the Web, independently
>> of what the HTML5 specification is currently saying. So, that makes me
>> wonder how relevant the HTML5 resolution on ISSUE-41 is going to be,
>
> If their use of xmlns attributes is limited to RDFa, and they don't use
> any namespaced elements or attributes other than xmlns:, then I think
> their use is covered by the HTML+RDFa specification:
>
> http://www.w3.org/TR/rdfa-in-html/

A few questions:

1) is the combination of HTML+RDFa plus Open Graph Protocol a 
"vendor-neutral extensions" permitted by the current draft of the HTML5 
specification[1]?

2) I don't believe that HTML+RDFa changes any parsing rules, but does 
change conformance rules.

2a) Can anybody confirm the above?

2b) If so, conforming RDFa will be parsed into a DOM differently based 
on the MIME type.  Does the RDFa draft make this clear?

3) Does this affect the Polyglot spec?

4) The current w3c validator declares this markup to be in error[2].  Is 
somebody planning on updating the validator to handle RDFa?

> Regards,
> Maciej

- Sam Ruby

[1] http://dev.w3.org/html5/spec/infrastructure.html#extensibility
[2] http://validator.w3.org/check?uri=http%3A%2F%2Fwww.jamesbalean.com.au%2F

Received on Thursday, 22 April 2010 21:00:49 UTC