Re: Catalogs (was RE: SGML entity mgmt stds)

[Ralph Ferris <ralph@xxxxxxxxxxxxxxx>]

Dave Pawson wrote:
>
>Date: Tue, 15 Jun 1999 07:38:58 +0100
>From: DPawson@xxxxxxxxxxx
>Subject: RE: SGML entity mgmt stds (was Re: ISUG and DSSSL)
>for someone new to this world, the catalog is a total
>mystery, any help would have been appreciated by
>myself in the early days.
>
>I'm having exactly the same problems with dir structure
>in the java world of XML. None of it seems to make sense.

"Catalogs" were developed by SGML Open (now Oasis) a few years ago as a
standard approach to resolving public identifers. For more information, see
http://www.jclark.com/sp/catalog.htm.

As for using the catalogs within the context of the directory structure,
I've just added a bin directory for CGI programs to the HyBrick Web site.
Using this for illustration, the directory structure is:

bin
bin/catalog
bin/writeback.cgi 

bin/styles
bin/styles/demo.dsl
bin/styles/catalog
 
bin/styles/dtd
bin/styles/dtd/dsssl.dtd
bin/styles/dtd/fot.dtd
bin/styles/dtd/style-sheet.dtd

bin/dtd
bin/dtd/demo.dtd
bin/dtd/xml.dcl


The bin/catalog entries are:
SGMLDECL "dtd/xml.dcl"
PUBLIC "-//FSC//Demo DTD//EN" "dtd/demo.dtd"

The first line, referencing the SGML declaration for XML, is needed because
the CGI program, writeback.cgi, outputs an XML document.

The bin/styles/catalog entries are:
PUBLIC   "-//James Clark//DTD DSSSL Flow Object Tree//EN"  "dtd/fot.dtd"
PUBLIC   "ISO/IEC 10179:1996//DTD DSSSL Architecture//EN"  "dtd/dsssl.dtd"
PUBLIC   "-//James Clark//DTD DSSSL Style Sheet//EN"
"dtd/style-sheet.dt 

These entries are needed to reference the architectural information and
DTDs required to process DSSSL style sheets. Note that the dtd directory in
this case is a sub-directory of the styles directory, not the bin/dtd
directory that contains the DTD for the instance itself. I didn't make this
clear in yesterday's message.

When you look over a list like this, and think about all the processing
steps involved - keeping in mind that all of these files (except the CGI
program itself of course) first have to be retrieved from the server - you
begin to realize why rendering SGML "over the Web" is something less than a
ball of fire. It's also obvious that numerous "optimizations" are possible. 

Those are developments for the future, though. If you care to try out the
CGI program itself, you can go to the HyBrick file open dialog and enter
something like:

http://www.fsc.fujitsu.com/hybrick/bin/writeback.cgi?a=b&c=d 

The program will send back a document showing the name/value pairs you
sent. If you want to see the "source" file itself, enter the same string
from an "ordinary" Web browser. The content-type that's sent back is
text/plain, so the browser doesn't attempt to call a helper app to display it.



Best regards,
 
Ralph E. Ferris
HyBrick Program Manager
Fujitsu Software Corporation
HyBrick: http://www.fsc.fujitsu.com/hybrick/
    



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