[DFDL-WG] new action item needed: DFDL URN specification

[Suman Kalia]

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 at ca.ibm.com

For info on Message broker
http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.html





From:   Mike Beckerle <mbeckerle.dfdl at gmail.com>
To:     dfdl-wg at 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 at ogf.org



I wanted to add to this discussion the w3c blog page that highlights the 
problem of the http-based naming scheme. There are many articles about 
this, this is just one of them.

http://www.w3.org/blog/systeam/2008/02/08/w3c_s_excessive_dtd_traffic/

On Wed, Oct 24, 2012 at 10:35 AM, Mike Beckerle <mbeckerle.dfdl at gmail.com> 
wrote:

Introduction:

Using URLs as identifiers has caused no end of problems. E.g., in DFDL we 
have http://www.ogf.org/dfdl/dfdl-1.0/ as an identifier. W3C has 
http://www.w3.org/2001/XMLSchema and others.

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




-- 
Mike Beckerle | OGF DFDL WG Co-Chair 
Tel:  781-330-0412
--
  dfdl-wg mailing list
  dfdl-wg at ogf.org
  https://www.ogf.org/mailman/listinfo/dfdl-wg
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.ogf.org/pipermail/dfdl-wg/attachments/20121025/3da1ac74/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/gif
Size: 48358 bytes
Desc: not available
URL: <http://www.ogf.org/pipermail/dfdl-wg/attachments/20121025/3da1ac74/attachment-0001.gif>