Re: More comments on WOFF metadata - 1

Hello,

Eric Muller wrote (via Christopher Slye):

> 1. all the WOFF elements should be in a namespace. This 
> would address the problem raised by Laurence Penney, and is 
> vastly preferable, IMHO, to a doctype declaration (see 
> the philosophy of RELAX NG for the reasons)
http://lists.w3.org/Archives/Public/www-font/2010OctDec/0083.html

Eric, Christopher, this is being tracked as last call issue 3.
http://dev.w3.org/webfonts/WOFF/DoC/issues-lc-2010.html#issue-3

This comment was discussed on the 01 Dec 2010 WebFonst WG telcon
http://www.w3.org/2010/12/01-webfonts-minutes.html#item02
This is the official response from the WebFonts WG, following that discussion.

It is true that placing an XML vocabulary in a namespace is a common and popular way to indicate which vocabulary is in use, particularly in situations where it may be mixed with other vocabularies. It is also true that a namespace is a better way to associate a given xml instance with its schema than an in-instance label such as a DOCTYPE declaration for DTDs or an xsi:schemaLocation for W3C XML schema.

Its also true that authors tend to dislike typing namespace URIs when they add no apparent benefit, or when mistyping one results in a loss of functionality. Experience with HTML in particular showed that namespace mechanisms were unpopular with the Web authoring community. HTML5 makes them optional for the HTML serialisation, and also for SVG and MathML when included inline in HTML5. Special parser support ensures that recognised elements are placed i the correct namespace in the DOM.

So there is a tension between two schools of thought, one Web-like and one XML-like, on how and when to use XML namespaces.

Without special parser support, however, namespaces are not optional. If a vocabulary is in a particular namespace, it must be declared in the instance and failure to do so means that the vocabulary is in a null namespace.

Thus, if WOFF were to move its vocabulary to an XML namespace, this would make invalid all deployed WOFF files; their metadata would not be in the WOFF namespace.

This hard break of backwards compatibility is seen by the WebFonts WG as quite unacceptable. WOFF is already widely deployed. Accepting this change request would require retooling and re-issuing all currently deployed WebFonts that use WOFF. The charter of the WG requires us to avoid such breaking changes:

"only make the minimal changes needed for interoperability and standardisation"
http://www.w3.org/2009/08/WebFonts/charter.html

Thus the WebFonts WG rejects this change, due to the impact on compatibility with deployed content.

Note however that we do not plan to add a DOCTYPE declaration of xsi:schemaLocation either; the schema is described in the WOFF specification using prose and a RelaxNG grammar, neither of which require an in-instance label.

Please let us know if you can accept this resolution of the WebFonts WG, and thank you for your comments. (The other comments you made will be the subject of separate emails, for tracking purposes).

Tracker, this relates to ACTION-51.

-- 
 Chris Lilley   Technical Director, Interaction Domain                 
 W3C Graphics Activity Lead, Fonts Activity Lead
 Co-Chair, W3C Hypertext CG
 Member, CSS, WebFonts, SVG Working Groups

Received on Monday, 10 January 2011 20:15:36 UTC