Re: Can identifier url="foo" be duplicated?

[Dan Mueth <muet alumni uchicago edu>]

I will try to answer some of these questions with a perspective of what 
ScrollKeeper was intended to allow, although I haven't written most of 
the OMF files in question.

On Wed, 24 Jul 2002, David Merrill wrote:

> Lampadas has a unique key on filename, so only a single document can point 
> at the same file. So, I am catching all of these as I try to import your 
> data.
> 
> I'm running into situations where more than one omf file is pointing to 
> the same source file. I reported the first one as a bug, since a Spanish 
> omf file was pointing to an English source, but now I'm running into 
> three omf files which all point to the same document, but use different 
> subjects/categories. I wonder if you are using multiple omf files to get 
> multiple category entries. Is this what you're doing?

One can specify multiple categories for a document within a single OMF 
file (or more technically, a single <resource> in an OMF file).

Having said that, I was initially a proponent of having ScrollKeeper key
on the full URL to a file (eg:  
file://usr/share/gnome/help/gpl/C/gpl.sgml).  A couple prominent hackers
convinced me not to do so.  Instead, ScrollKeeper just numbers the OMF
resources (ie. <resource>) as they are registered and keys off of that.  
This allows multiple OMF files or resources to refer to the same document
if they choose.  In principle, it allows a single OMF resource to point to
multiple possible locations of the document.  This isn't too useful right
now, but if ScrollKeeper grows to be network-enabled, it would be useful
to point to multiple copies at different places on the Net (ie. document 
URL fallback).


> Also, are you sharing files as entities among multiple documents? If so, I 
> will have to remove the unique index and check for duplicates only among 
> "top" files.

This is a useful thing to be able to do and we've discussed it on a number
of occassions.  I'm not sure if we are doing it right now.

> I hope I am not being a pest asking all of these questions and needing 
> some hand-holding. I do appreciate your help very much.

Not at all :)

-Dan