Re: [xml-dev] The purpose of a namespace URI is ...

[Michael Sokolov <sokolov@ifactory.com>]

On 12/2/2012 10:44 PM, John Cowan wrote:
> Liam R E Quin scripsit:
>
>> But I'm not convinced: public identifiers need indirection, and if you
>> have indirection you can ue indirection for the system identifiers too.
> You were there and I was not, but what I understood was that public ids
> were absolute names and system ids were meaningful to the current process.
> So given a URI as a public id, you could dereference it if no system id
> was present, or you could make use of the system id to find a specific
> copy of it.
But in practice it seems more convenient to keep DTDs in local storage 
(separate from document storage) and use a catalog or similar mechanism 
to find them, and this requires circumventing these primordial notions 
about how to look up DTDs.  At least that's my antediluvian perspective.

The default lookup schemes do lead people into unhelpful paths. public 
ids as urls lead to w3c being bombarded with requests. And we have 
customers that deliver us a copy of the DTD *with every document*, and 
consumers that require same, in an effort to get relative system ids 
(with no path, which makes sense if you think of this as an 
*identifier*) to work.

-Mike