Re: Comments on 28022000 draft: Lack of expressiveness in DTDs

At 16:36 00/03/01 +0100, Gregor Karlinger wrote:
 >But how should we express this "freedom" with the limited means
 >of the DTD content model for an element?
 >
 >* (#PCDATA) limits the allowed content of the element to character
 >  data only; no tags are allowed.
 >
 >* (ANY) limits the allowed content to any elements DEFINED WITHIN
 >  the DTD; so this is also too restrictive.
...
 >In any case, I think (ANY) would be a better approximation than (#PCDATA),
 >which is currenlty used.

I was thinking #PCDATA might be the better route, I didn't like the sentence
that we interpret what ANY means as it is clearly defined by the XML spec.
However, I'm not convinced this is the right choice, this is something I
hope we get more feedback on. Regardless, a validator [1] will fail on
examples of either case. [2] is an example where there is mixed content in a
Signature Method with the #PCDATA version of the DTD; [3] is the same
example using ANY. Both cause errors ...

[1] http://www.stg.brown.edu/service/xmlvalid/
[2] http://policy.w3.org/0229/signature-pcdata.xml
    http://policy.w3.org/0229/xmldsig-pcdata.dtd      
[3] http://policy.w3.org/0229/signature-any.xml
    http://policy.w3.org/0229/xmldsig-any.dtd    

_________________________________________________________
Joseph Reagle Jr.   
Policy Analyst           mailto:reagle@w3.org
XML-Signature Co-Chair   http://www.w3.org/People/Reagle/

Received on Wednesday, 1 March 2000 11:57:18 UTC