Re: Another day, another idea: generic handling of fragment identifiers

lilley (lilley@afs.mcc.ac.uk)
Fri, 1 Sep 1995 12:31:03 +0100 (BST)


Larry Masinter wrote:

> Right now, #fragment identifiers are only interpreted for URLs that
> resolve to text/html. I'd like to push forward to define some
> interpretation for fragment identifiers for other media types.

Ha! I was just thinking the other day that fragment identifiers for
VRML would be a good idea (corresponding to new views - view point,
view direction and view up vector).

> First, we define that each media type in the MIME registration may
> optionally define a semantics for fragment identifiers for that media
> type.

Yes.

> Second, we define the meaning of fragment identifiers for the
> media types commonly recognized by web browsers: image/gif &
> image/jpeg, video/mpeg, audio/basic, multipart/*.

Why specify subtypes (except for application/*, sure).

> For images, this might be an area which should be highlighted or
> scrolled to,

Yes, so why not define that for the image primary type and then any
off image format that happens to need different behaviour can always
define that in the MIME registration.

That means that new image subtypes, for example, would inherit the
default behaviour.

> This requires a bit of work, and imposes on future MIME type
> registrations to define (if desired) a semantics for fragment
> identifiers, but it regularizes the use of #nnnnn for things other
> than HTML.

Where do the fragment identifiers appear in a MIME email message? In
other words is this just a URL or HTTP issue, or does it apply to MIME
in general?

> I'd like to define the fragment identifier for application/postscript
> and application/pdf as a page number or range, for example, perhaps
> augmented with an offset.

OK, but ensure you have both external and internal page numbers. A
PostScript file could have more than one page 1 for example. See the
definition of the %%Page meta-comment in the Postscript Language Reference
Manual for details.

-- 
Chris Lilley, Technical Author
+-------------------------------------------------------------------+
|       Manchester and North HPC Training & Education Centre        |
+-------------------------------------------------------------------+
| Computer Graphics Unit,             Email: Chris.Lilley@mcc.ac.uk |
| Manchester Computing Centre,        Voice: +44 161 275 6045       |
| Oxford Road, Manchester, UK.          Fax: +44 161 275 6040       |
| M13 9PL                            BioMOO: ChrisL                 |
|     URI: http://info.mcc.ac.uk/CGU/staff/lilley/lilley.html       | 
+-------------------------------------------------------------------+