RE: ACTION ITEM: draft general section about extending/customizing schemas (http://www.w3.org/International/its/track/actions/1)

Hi Christian,
Some notes:


> The "How to do this" parts of this document often contain 
> statements related to schema creation or modification. The 
> statements pertain to one of the following state-of-affairs:
>
> 1. creating a schema from scratch

s/schema from scratch/new schema/

I'm not sure about "state-of-affairs" (but can't think of something better for now).


> 2. modifying an existing schema 
>
> The following aspects may need to be taken into account when 
> working on both of these topics:
> 
> 1. Think twice before creating your own schema. Consider strongly 
> existing formats such as DITA, DocBook, OpenOffice, XUL, UBL, ... 
> Those formats have many insights 'built-in'.



> 2. The mechanisms which you can or have to use depend on the schema 
> language (DTD, XSD, RelaxNG, ...). Namespace-based modularization 
> of schemas for example is hard to realize for DTDs.

s/is hard/is difficult/


> 3. Very often each schema formalism provides several possibilities 
> related to modification. XSD for example provides statements such 
> as "import", "include", or "redefine" as well as mechanisms such 
> as type substitution/derivation.

Maybe:

"Each schema formalism provides ways of extending or modifying existing document types. For example, XSD provides..."


> 4. What's possible also depends on the features of the schema 
> which the modification is targeting. Examples:
>
> - An XSD "redefine" for example only is only possible if the 
> modified schema has been created with named types.
>
> - If you are working with XSD, your options depend on the question 
> whether the schemas involved define target namespaces (techniques 
> such as working "chameleon" or "proxy" schemas may be considered 
> as solutions in certain cases).
>
> 5. The format itself should be carefully checked with regard 
> to modification capabilities. DocBook and DITA for example 
> come with their own set of features for adapting them to a 
> special need.


That's all for now.

Cheers,
-yves

Received on Wednesday, 5 September 2007 02:35:14 UTC