Re: [office] vialotaion of relaxng schema constraints

[Lars Oppermann <Lars.Oppermann@Sun.COM>]

Hi,

I brought this on up on xml-dev and it looks like I wasn't right after 
all - which I consider to be a quite fortunate thing in this matter :)

As sec. 7 of the RelaxNG spec states, restrictions apply after the 
grammer has been simplified. Section 4.19 defines the simplification 
applied to ref elements.

This seems to be a bug in xmllint's simplification algorithm, and we 
thus shouldn't change anything.

Bests,
~Lars


Michael Brauer wrote:
> Hi,
> 
> Lars is right. According to §7.1.3 of
> 
> http://www.oasis-open.org/committees/relax-ng/spec.html
> 
> refs within lists are in fact prohibited. This issue could be resolved by
> 
> a) replacing the reference with the content of the reference definition, or
> b) by replacing the lists themselves with a string data type.
> 
> While the first solution increases the size of the schema and makes it
> harder to read, the 2nd solution makes the schema less strict regarding
> validations
> 
> I've checked the occurences of "ref" within "list" in our spec. Where
> are two kinds of them:
> 
> 1. References to data types. The data types referenced are: integer,
> double, percent, length, positiveLength.
> 
> 2. References to defines containing choices of values. An example is the
> definition of "style:position" in  "15.4.23 Paragraph Background Color".
> 
> It seems that solution a) doesn't make the schema completely unreadable
> in both cases, so I propose to choose that option.
> 
> Michael
> 
> 
> Lars Oppermann wrote:
> 
>>Hi folks,
>>
>>I just checked out validation of some documents against the schema with 
>>libxml2's xmllint. I have never used that before but wanted to check out 
>>libxml2's relaxng support.
>>Well, lots of errors but all of the same type:
>>
>>office-schema-1.0-draft-19.rng:13704: element ref: Relax-NG parser error 
>>: Found forbidden pattern list//ref
>>
>>And it's right, ref isn't allowed in lists; (see section 'list 
>>constraints' at http://books.xmlschemata.org/relaxng/ch17s02.html)
>>
>>I'm not quite sure about the implications of this, since I'm not an 
>>expert at all on relaxng matters. Replacing refs with the original 
>>definition would fix the error but we'd lose the nice abstraction level 
>>we've got by using defines for patterns (like e.g. percent)
>>
>>Any suggestions?
>>
>>Bests
>>~Lars
>>
> 
> 
> 


-- 
Lars Oppermann <lars.oppermann@sun.com>               Sun Microsystems
Software Engineer - StarOffice                           Sachsenfeld 4
Phone: +49 40 23646 959                                D-20097 Hamburg
Fax:   +49 40 23646 550                  http://www.sun.com/staroffice