RE: [opendocument-users] RE: Foreign elements and attributes

["Dennis E. Hamilton" <dennis.hamilton@acm.org>]

A couple of clarifications concerning what I was thinking of at the time.

 2. When attribute names are the same: With regard to multiplicity and repetition, there is no such thing at the attribute level.  An element can have at most one attribute of a given name.  The sameness of attribute names is as determined by [XML 1.0] and [xml-names].  Although one can come up with some pretty hairy attribute syntax to allow for multiple values of some sort, it is not directly comparable and it is definitely messy.  I note that this road has been taken in some specifications, especially for embedding one kind of markup in another, but it is a clumsy route right up there with use of CDATA for the same purpose.
   Short answer: If the combination of (possibly absent) namespace and local name are different, the attribute name is different.  

 3. Using attributes to smuggle content: My observation about using spanning devices such as <div> and <span> was not related to the addition of content, any more than attributes of the current <text:span> and the proposed <text:meta> of ODF 1.2 are used to do that.  
   However, the need for <text:meta> because you can't have multiple RDF relations via RDFa attributes of a single element is a good demonstration of a situation where multiplicity is required.  Of course, in a pure RDF/XML situation, this is handled by multiple occurrences of <rdf:Description> elements in an interdependent way.  
   (The injection of <rdf:Description> elements into ODF elements, with a nice RDFa seasoning, is a perfect example of benign foreign-element-and-attribute usage, of course, but instead there is an ODF-unique approach that strikes me as baroque and convoluted.)  
   The RDFa workaround for annotating elements in an existing document model (i.e., XHTML and presumably HTML 5) is by use of <xhtml:span> and similar niceties to make enough of the needed attributes and their interdependencies available.  (The narrower ODF 1.2 solution seems to be incomplete, with the importance of xhtml:rev and its equivalents apparently overlooked.)

 - Dennis

-----Original Message-----
From: Dave Pawson [mailto:dave.pawson@gmail.com] 
Sent: Wednesday, March 04, 2009 08:56
To: dennis.hamilton@acm.org
Cc: ODF Users List
Subject: Re: [opendocument-users] RE: Foreign elements and attributes

2009/3/4 Dennis E. Hamilton <dennis.hamilton@acm.org>:
[ ... ]
>
> 2. One problem with the use of attributes only is that there can only be one
> occurrence of an attribute of the same name per element.  There is no
> provision for multiplicity, repetition, etc.

Same local-name, different namespace?
Are they 'different'?

>
> 3. One way to deal with situations like (2) is to use the ODF counterparts
> of <div> and <span> or (hack, cough) the ODF bookmark provisions that allow
> hierarchy to be transcended in the manner exploited by the RDF Metadata
> feature.

Scenario. You are an implementor. You come across a valid ODF element
with foo:bar="The quick brown fox" as an attribute.

Would it make sense to treat this as content? I don't think so.

[ ... ]