Steve Hanson
Architect, Data Format Description Language (DFDL)
Co-Chair, OGF
DFDL Working Group
IBM SWG, Hursley, UK smh@uk.ibm.com
tel:+44-1962-815848
From:
Suman Kalia <kalia@ca.ibm.com>
To:
Mike Beckerle <mbeckerle.dfdl@gmail.com>,
Cc:
dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org
Date:
25/10/2012 17:15
Subject:
Re: [DFDL-WG]
new action item needed: DFDL URN specification
Sent by:
dfdl-wg-bounces@ogf.org
I tend to agree that specifying
urn for namespaces is better choice and URL should be used for schema
locations; however convention of specifying URL for namespaces is
long established some implementations use the namespace URL to return
the actual schema. When I try to access the namespace
URL for XML schema , it gives me reference to the document but not schema..
Suman Kalia
IBM Canada Lab
WMB Toolkit Architect and Development Lead
Tel: 905-413-3923 T/L 313-3923
Email: kalia@ca.ibm.com
From: Mike
Beckerle <mbeckerle.dfdl@gmail.com>
To: dfdl-wg@ogf.org,
Date: 10/25/2012
08:18 AM
Subject: Re:
[DFDL-WG] new action item needed: DFDL URN specification
Sent by: dfdl-wg-bounces@ogf.org
W3C has badly regretted establishing this convention, as they have farms
of servers that do nothing but quickly return 404 errors to save network-aware
applications the network-timeout delay that would otherwise occur.
There are parties interested in exploiting DFDL who want DFDL schemas to
NOT contain network URLs because it simply creates a concern about network
access whenever a DFDL schema is inspected/used.
Pre-Proposal:
The new way to do this is with URNs which would look roughly like this:
urn:ogf:dfdl:standard:dfdl-1.0. The whole point is that some other mechanism
is used to establish correspondences between these and any resources in
file systems, networks, or built-in to implementations. One such mechanism
is called XML Catalog.
The point is that it is a name in a managed namespace which cannot be confused
with a network protocol URL.
OGF is already establishing urn:ogf, and an ogf subgroup has already proposed
urn:ogf:network for network resources. DFDL schemas aren't network resources
so we don't want to be a substructure underneath network.
Some other mechanism is used to establish correspondences between these
and any resources in file systems, networks, or built-in to implementations.
One such mechanism is called XML Catalog.
Summary:
An action item should be to specify DFDL urn, submit to OGF as a proposed
namespace, and then produce errata/spec changes to specify its use.
This requires a small design activity to specify a scheme for the sub-structure
of the DFDL URNs (i.e., scheme for the stuff after urn:ogf:dfdl:...) where
we want standard identifiers for versions of the standard, but we probably
also want a few other things (e.g., I would like a space for implementations
to identify themselves, i.e., an implementation-specific sub-area within
our URNs.)
Our existing URLs can be compatible (deprecated) practice vs the preferred
URNs.
--
Mike Beckerle | OGF DFDL WG Co-Chair
Tel: 781-330-0412
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