Re: Hyperlinks: MPRDV
Subject: Re: Hyperlinks: MPRDV
From: Martin Bryan <email@example.com>
Date: Fri, 20 Dec 1996 09:13:16 +0000
From firstname.lastname@example.org Fri Dec 20 04: 14:23 1996
X-Mailer: Windows Eudora Light Version 1.5.4 (32)
>3. Minimum Progress on Hyperlink Enhancement
>The minimum set of hyperlink constructs should:
>3.1 subsume the existing WWW Anchor semantics in a smooth and natural way.
>3.2 provide a hyperlink mechanism with richness similar to that of the
> HyTime "ilink" construct. This means that the link
> - has a type,
> - has multiple ends, each of which has a role, and
> - may be located away from any of its ends, thus supporting links into
> read-only material.
>3.3 support addressing at least by URL and ID attribute, alone or
> in combination.
There is a vital element missing here - the ability to address part of an
object that does not have an ID (or a name attribute if we are to fully meet
3.1) associated with it. If we are going, as claimed in 3.2 to "support
links into read-only material" we have to presume that the objects we are
pointing to have not been named in a reasonable way. Therefore we need an
addressing mechanism that can identify any part of any document. URL and ID
are not sufficient, either alone or in combination.
I would also argue strongly for letting a single anchor role point to
mutliple locations, which is not possible when you say "has multiple ends,
each of which has a role". Anchor roles can type location sets, just as the
ilink construct allows you to type links.
Incidentally, in the HyTime TC ilinks will become a deprecated form: the
extended HyLink architectural form will subsume their role and would form a
better basis for this work. (More on this later, if Eliot does not beat me
Martin Bryan, The SGML Centre, Churchdown, Glos. GL3 2PU, UK
Phone/Fax: +44 1452 714029 WWW home page: http://www.u-net.com/~sgml/