RE: RFC2518 (WebDAV) / RFC2396 (URI) inconsistency

I think Jim makes a good case here.

It is particularly convenient that "foo:" is not
allowed as a relative URI, since otherwise the
use of "foo:" as the URI for the schema would
be ambiguous.

<humor> And this would retroactively give us a
much better answer for why "foo:" is not a legal
relative URI </humor>

Cheers,
Geoff

-----Original Message-----
From: Jim Whitehead [mailto:ejw@cse.ucsc.edu]
Sent: Monday, November 26, 2001 1:26 PM
To: Roy T. Fielding
Cc: 'WebDAV'; uri@w3.org
Subject: RE: RFC2518 (WebDAV) / RFC2396 (URI) inconsistency


Roy Fielding writes:
> OTOH, I have found at least one other example -- the "about:" URL in
> Netscape Navigator -- so I guess this could be changed in a
> future revision of 2396.

A very principled case can be made for viewing the scheme namespace as a set
of URIs. This URI space identifies URI/URN/URL scheme names.

A scheme identifies a resource, the abstract concept of the particular
identifier of locator space. For "http" scheme URLs, the URI "http:"
identifies the abstract notion of locators for Web resources accessed via
the HTTP protocol. The "dav:" URI identifies the abstract concept of
property and XML element names used in the WebDAV family of protocols.

Put another way, there is a set of resources:

{{The abstract notion of locators for Web resources accessed via the HTTP
protocol},
{The abstract concept of property and XML element names used in the WebDAV
family of protocols},
{The abstract concept of locators for directory resources accessed via the
LDAP protocol},
{The abstract concept of identifiers for people's email inboxes}}

These resources map to the following URIs:

{"http:", "dav:", "ldap:", "mailto:"}

Once you accept that these are all valid URIs, then RFC 2396 can be viewed
as needing revision to remove the (artificial) constraints on URI syntax
that prevent the use of scheme name URIs.

- Jim

PS - So, yes, I am reversing my earlier opinion that RFC 2396 does not need
revision.

Received on Monday, 26 November 2001 13:54:34 UTC