Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!mailrus!iuvax!ndcheg!ndmath!milo
From: milo@ndmath.UUCP (Greg Corson)
Newsgroups: comp.sys.mac.programmer
Subject: Sublaunching (really user extendable programs)
Message-ID: <1529@ndmath.UUCP>
Date: 12 Aug 89 21:37:26 GMT
Organization: Math. Dept., Univ. of Notre Dame
Lines: 40

I need to put together a program that can be extended by adding other
programs to it.  The configuration I need is one "core" program that would
have the ability to chain out to a "satelite" program, then come back to the
core when the satelite exits.

Obviously, I can do this with sublaunching...but lots of the Apple technotes
say sublaunching is to be avoided for compatability reasons.  So how do I do
this??  Just "launch" to one program and have it "launch" back to the core
when it's done?  I suppose it would work, but I would have to pass 
info somewhere that would let the core program come back up in it's current
state.

In this particular case, my "core" program is a set of icon point-click menus
and a terminal program.   The satelite programs are specific 
telecommunications applications.  The way I need it to work is something like
this.

User gets online and into main menu...then clicks a choice like "airline
reservations" the core program launches off into the airline reservation
program which eventually returns to the core.  Later on, the user sees a 
new service on line, say computer shopping.  The core program determines
that there is no support program for computer shopping on the users disk
so it downloads it from the host, then launches to it.

The program can't be just one big mass, it needs the ability to have whole
new sections (possibly major ones) added.

Under a Unix or VMS type operating system....you'd just have a core program
that spawned off subtasks which would later return to the core when done.

On the Mac, this sounds like sublaunching....but we're not supposed to do that
for compatability reasons...so what's the next best way to handle it??


Greg Corson
19141 Summers Drive
South Bend, IN 46637
(219) 277-5306 
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