Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!uunet!mcvax!ukc!strath-cs!turing!arthur
From: arthur@turing.ac.uk (Arthur van Hoff)
Newsgroups: comp.windows.news
Subject: Re: NeWS applications should not depend on file access on the server
Message-ID: <644@tivax.turing.ac.uk>
Date: 5 Jun 89 11:14:49 GMT
References: <7506@hoptoad.uucp>
Reply-To: arthur@turing.ac.uk
Organization: Turing Institute, Glasgow, Scotland.
Lines: 34

Hi there,

Some remarks have been made on the file usage of GoodNeWS applications. It
is true that for standard applications it is NOT a good idea to load a
PostScript file using the server. There are some situations where it
is forgivable:

	- If the file is part of a standard interface and therefore has
	  to be available to the server anyway.
	- If the application is entirly written in PostScript.
	- If you are using a low-bandwidth connection. Here is your own
	  responsibillity to make sure that the remote server will be
	  able to access the file.

One problem remains. You need to specify a full-pathname when a file is
loaded from the server. This is caused by the fact that the server may have
a different current-directory than the application. 

In GoodNeWS/HyperNeWS (where most applications are entirely PostScript based) 
a simple but not very effective solution was used. 
A routine called "ExtendFileName" was implemented which attempts to open a
file by searching a number of directories depending on the file extension.
This allows you to store a set of PostScript files in library directories 
which can be loaded without specifying a full pathname. For example:

(test.draw) ExtendFileName 	---> (/usr/arthur/draw/tmp.draw)
(~/help/text.1) ExtendFileName 	---> (usr/arthur/help/text.1)
(arthur.img) ExtendFileName 	---> (/usr/local/GoodNeWS1.2/img/arthur.img)

At the moment the list of directories which are searched is fixed. A good
idea would be to specify a list of directories using an environment
variable.

Arthur van Hoff