Well said. I started a draft on this one time:
Toward Reliable, Interoperable Links
$Id: link-rpc.html,v 1.1 1995/02/14 22:41:10 connolly Exp $
http://www.w3.org/hypertext/WWW/People/Connolly/drafts/link-rpc.html
Very much work in progress. Mostly raising issues without presenting
any solutions. Here's an excerpt:
|The Uniform Resource Locator is beoming a widespread way to address
|resources on the internet. It's used in WWW, and folks are putting
|them in email messages, USENET news articles, BibTeX databases, and
|even business cards, newspaper articles, and magazines.
|
|OK... in all of these cases save the WWW/HTML case, the URL is
|consumed by a human reader, who has the capability to decide how much
|of the data is a URL and how much is wrappers, containers, or just
|other "stuff."
|
|But before long, we'll see URL style hyperlinks in TeX, Adobe's PDF,
|probably MIME external body references, and all sorts of other data
|formats where the URL is consoumed wholly by machine with no manual
|intervention.
|
|Another context where URLs are used more and more is the "desktop
|message bus" -- cut/copy/paste, drag-n-drop and clipboard types on X,
|Mac, Windows, and NeXTStep patforms. Apple Events, OLE 2, and even
|local-area and wide-area RPC systems based on CORBA, and DCE.
|
|So it becomes pretty important to know what the "type" or "bandwidth"
|of a URL or a URL-based link is -- what's its expressive capability.
|
|For most applications, it appears that a single "token" or "string
|with no spaces" is enough. The fact that entire HTML forms queries are
|encoded in URLs regularly shows that this can be pretty expressive.
|
|But for other applications, folks are putting linking information
|outside the single URL token. In the S-HTTP proposal[1] for example,
|to make a secure link or a secure form submission, you need a DN or
|distinguished name attribute (and possibly some others) in addition to
|the URL. In the BRIO[2] system, additional anchor attributes are
|necessary to support a rich annotation system.
|
|So what if I want to cut-and-paste a secure link? A link to a
|replicated object? Do I loose all the info except the URL? Bad
|news. Perhaps the "type" of a link is not just the HREF part of the
|anchor tag, but the whole tag: HREF, DN, URN, etc.
See also:
Resource Discovery and Reliable Links
http://www.w3.org/hypertext/WWW/People/Connolly/drafts/citations.html
$Id: citations.html,v 1.11 1995/02/14 22:41:05 connolly Exp $
>1. Links to Dynamic Documents.
>
>What are the semantics of linking to dynamic documents, objects
>whose copies modify themselves?
In order to have a productive discussion on this, we're going to have
to nail down some terms. The terms "object" and "resource" tend to
defy definition. I regard them as anything you can name with a URI.
So objects/resources are identicial by definition if their URIs are
identical.
Then to talk about what goes over the wire, I tend to talk about
representations of resources, or "entities" -- these are sequences
of octets with some associated type information.
So I don't know what a "copy of an object" means. I know about
representations of objects...
> What does a URL mean now?
In the HTTP model, all objects are dynamic. The representations of
an object are assumed to change over time. And an object may have
multiple representations at any given time.
> Note
>that even today's clients can have multiple objects keyed to same
>URL,
Not so, at least the way I see things. Remember: objects with
the same URL are identical by definition. They have multiple
representations...
Gotta go. More as time permits.
See also:
A Formalism for Internet Information References
http://www.w3.org/hypertext/WWW/People/Connolly/drafts/formalism.html
$Id: formalism.html,v 1.6 1995/02/08 08:19:38 connolly Exp $
Dan