xml-dev - Re: XML Schemas: Best Practices

["Thomas B. Passin" <tpassin@home.com>]

Jon Cleaver responded to Roger Costello's post -

> Roger, All,
>
> There appears to be a convergence of thought that the
design of an XML
> schema is somewhat analogous to the creation of an Object
Oriented Design
> for a piece of code. There are instances where you want to
maximise
> component reuse and instances where you want data to be
private. There are
> also instances where you want to combine both of these.
>
> What are the guidelines for creating private and public
members of an OO
> class? Is there a best practice for this - I assume there
must be one as
> part of an OO design course. Personally, I just decide
which components are
> needed to be viewed and which I would rather have left
alone.
>
> It seems to me that a fair chunk of this thinking will
have already been
> tackled by our OO design brethrin and there will be a
published set of
> guidelines. It is just a matter of finding them and their
application to
> this problem.
>

 Many principles for OO programming or design are the same
as for any other software development, and could (should, I
think) be applied to document or data design too.  Among
them:

1) Minimize interactions between components  (or modules,
functions, objects, etc.).

2) Organize components into well-defined layers to help
minimize interactions.  The goal is to have components of
one layer use only components from one other layer wherever
possible.

3) Anticipate what kind of extension might be desired in the
future,  and provide for it now so that you can extend the
system with minimal disruption later.

4) Adopt a naming convention that helps explain the purpose
of each component, and use it.

These lessons (anyone should feel free to add more) have
been learned the hard way over the years.  Why not take
advantage of them?

Cheers,

Tom Passin