[jsdl-wg] my view on execution user and group

[Ian Stokes-Rees]

Hi,

I only have one follow-up comment to the replies I received:

William Lee wrote:
> I'm not sure what you mean by "namespace the same as a resolvable URL". 
> The namespace "http://www.ggf.org/namespaces/2005/03/jsdl-o.9.4.xsd" is 
> just an URI, it has no meaning apart from a string that satisfies the 
> required URI syntax. Whether or not that "http://..." string resolves to 
> a network resource or not is not implied and often a cause for confusion.

Namespace are confusing, period.  I have worked with XML for several 
years and still find it difficult to get my head around all the rules 
for scoping, schema declarations, default NSs, null NS, chameleon NSs, 
attribute vs. element NSs, etc.

My reading of xml-dev general-opinion and (the xsdl-dev mailing list 
when I used to read it) is that everyone agrees it was a mistake to use 
"http://..." for something which *looks* like a URL but, in fact, is 
just a URI and does not (nor perhaps ever will) actually resolve.  It is 
ashame that this has not been embded in the XSDL Schema primer and has 
been widely adopted.

My very strong recommendation would be (in this order):

1. Definitely do not put ".xsd" at the end of the NS.  That 100% looks 
like you are giving a NS with a one-to-one mapping to a resolvable URL 
to the schema for that namespace.

2. Do not put "http://" at the start.  Use "uri:" or "urn:" instead.

3. If you do you "http://" or "*.xsd" then make sure it *does* resolve 
to something, probably to the "master" or "top-level" schema file.

A not-altogether-bad approach might be to have (for example)

urn:www.ggf.org/schemas/jsdl/2005/04

and then convince someone that the URL:

http://www.ggf.org/schemas/jsdl/2005/04/

should provide some information about where to actually find the various 
XSD files (by set, by version, etc.) -- perhaps at:

http://www.ggf.org/schemas/jsdl/2005/04/jsdl-2005-04.xsd

(yes, I know, for redundant see redundant, but it means if the file is 
copied locally it still has a sensible name).

Anyway, just my thoughts on this.

Cheers,

Ian.

-- 
Ian Stokes-Rees                 i.stokes-rees at physics.ox.ac.uk
Particle Physics, Oxford        http://www-pnp.physics.ox.ac.uk/~stokes