- From: Mark Birbeck <mark.birbeck@x-port.net>
- Date: Mon, 24 Mar 2008 14:34:47 +0000
- To: "Laurens Holst" <lholst@students.cs.uu.nl>
- Cc: public-rdf-in-xhtml-tf@w3.org
Hi Laurens, > I have two comments on the current RDFa in XHTML Syntax draft [1]: > > First of all, I think the @cite attribute on blockquote and q elements > should have the same status as @href (be considered as @resource), so > that RDFa can pick up on existing cite attribute annotations in > documents, and to avoid authors having to write the citation URI twice, > one for RDFa and one for HTML. See the example in section 6.3.2.1. Speaking for myself, I absolutely agree. :) However, I have never pushed this in the current version of RDFa, because in some research that I did for the IPTC a while ago, it looked like you could create a general rule where: any attribute + value is equivalent to: bnode + predicate based on attribute name + value You'll see that @instanceof follows this pattern: @instanceof="t" => _:a rdf:type <t> . A similar example would be @role: @role="r" _:a xhv:role <r> . And I think @cite should behave the same way, since it is the citation of a quote: <blockquote property="ab:cd" cite="http://www.example.org/source" > Some text. </blockquote> Would give: _:a ab:cd "Some text." . _:a xhv:cite <http://www.example.org/source> . Where ab:cd was some appropriate predicate for a quote. However... I'm explaining all of this, only to show that there would be much to discuss in resolving this issue. And I think it would be too much to hope to use @cite in a way that everyone would agree on, in this version of RDFa. My suggestion would be to leave this until the next version. > Second, are you sure that it is a good idea to give @src different > semantics than @href? I think it would probably be better if they had > the same semantics in RDFa. The reason for this is that I find the > difference between overriding @src and @href values (as explained in the > Primer [2] section 3.6) confusing, and it is not really clear to me why > they are treated differently. After all, they both reference a resource > in a very similar manner, only differing in the way the resource is > displayed. > > The usefulness of treating @src as @about also seems to be rather > limited, as <img> can not have child content and you can thus specify at > most three triples; one with a literal object, one with a resource > object, and one reverse relation of the resource. Or, maybe @href should > also be treated as @about? You are right that there is not a great deal of difference between using @src as a subject or an object in the presence of @rel. However, by making @src act as a subject, you are able to make use of an image in some statement, and then say something about the image. For example, you could say that someone has a picture, and that the picture is licensed under some CC license: <div about="#me"> <span property="foaf:name">Mark Birbeck</span> <span rel="foaf:depiction"> <img src="pic.png" rel="license" resource="http://cc..."/ > </span> </div> If you let @src play the role of an object, then you'll see that you can only make one or other of these statements in a compact way, and then you have to repeat the URI for the image, in order to indicate the second statement. For example: <link about="pic.png" rel="license" href="http://cc..." /> <div about="#me"> <span property="foaf:name">Mark Birbeck</span> <img rel="foaf:depiction" src="pic.png" /> </div> (This is not an official response from the group, I'm merely letting you know the thinking that lay behind this.) > I hope these comments (although a few days late for the comments > deadline, I understand) will be useful for you to improve the specification. They have been useful, thank-you. Regards, Mark -- Mark Birbeck mark.birbeck@x-port.net | +44 (0) 20 7689 9232 http://www.x-port.net | http://internet-apps.blogspot.com x-port.net Ltd. is registered in England and Wales, number 03730711 The registered office is at: 2nd Floor Titchfield House 69-85 Tabernacle Street London EC2A 4RR
Received on Monday, 24 March 2008 14:35:24 UTC