W3C home > Mailing lists > Public > public-tt@w3.org > October 2008

Issue 1 - metadata

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Thu, 16 Oct 2008 12:10:02 +0100
To: "public-tt@w3.org" <public-tt@w3.org>
Message-ID: <90EEC9D914694641A8358AA190DACB3D2802BE4513@EA-EXMSG-C334.europe.corp.microsoft.com>
> 8. Discussion items and errata

>     a) metadata.

>         Why do we need to allow more than 1?



<Glenn>

The tt:metadata element was designed first as a location context sensitive

container for non-TT related metadata vocabulary, i.e., vocabulary defined

in some non TT namespace, and second, as a similar grouping element (of

convenience) for TTM vocabulary. You will notice that, when expressed in

content elements, the semantics of any metadata information contained in the

Metadata.class elements are said to apply to the element in which it appears

as a child, as well as that element's descendants. As such, the metadata

information is semantically tied to its location of specification in the

element tree. In the case of tt:head, any Metadata.class element is said to

apply to the document as a whole. If you recall, one of the purposes of the

metadata element was to serve as a container for Dublin Core metadata, and,

in that regard, it is consistent to permit its specification in multiple

contexts.

</Glenn>



I think you may have slightly misunderstood my question; I might rephrase it in the light of your comment as, why do we need to allow more than one in each context.

We currently have effectively

(metadata | ttm:agent | ttm:copyright | ttm:desc | ttm:title)*



On each allowed context. I'm asking whether the Kleene star is necessary here.





>         Should ttm:* elements be children of metadata, or can we get rid of

> metadata?



<Glenn>

As the DFXP schema is currently specified, it is the option of the author to

place ttm:* elements in a containing tt:metadata element. This is more a

matter of convenience and grouping that the author can exploit as they wish.

I think this is a useful convenience that should not be jettisoned. Nor

should tt:metadata be removed for the reasons outlined above.

</Glenn>



Yes I understand the options, I'm not sure why we need both forms;



Is there sufficient semantic difference between:

<head>

      <metadata>

            <ttm:agent ..../>

            <dc:othermetadata.../>

      </metadata>

</head>



And



<head>

      <metadata>

            <dc:othermetadata.../>

      </metadata>

      <ttm:agent ..../>

</head>



To justify the latter is all I'm asking.



Sean Hayes
Media Accessibility Strategist
Accessibility Business Unit
Microsoft

Office:  +44 118 909 5867,
Mobile: +44 7875 091385
Received on Thursday, 16 October 2008 11:11:07 GMT

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