[comp.sys.mac.hypercard] check for laser xcmd

jm7f+@andrew.cmu.edu (Joe Melvin) (07/14/89)

Normal applications know right away if there is no laserWriter file
in the system folder, and also find out fairly quickly if the appleTalk
connection has been pulled out.  Does anyone know if there
is an xcmd/xfcn around that can check these things?  Something that
returned false if there was no laserPrep/laserWriter file or if there
was no appletalk connection would be perfect.

Here is a brief description of what happens when using one of the
printing xcmds without this type of error checking.
I am using the printField xcmd in a stack I am currently writing.
Someone who was testing the stack said he tried my "Print" button
and his mac hung - when he re-booted he said none of his stacks would
work and he had to  replace his copy of the hyperCard application.
He said he was not connected to a laserWriter or appletalk, was using
a mac plus, and I doubt he had laserWriter or laserPrep in his system
folder (don't ask me how he thought he could print).

I tried to replicate his experience and was unable to, even when I
removed laserWriter and laserPrep from the system and disconnected
my appletalk connection.   Yanking the appletalk connection did not
do much - the xfcn displayed it's "Looking for laserWriter ___" message,
the message stayed up a while, then went away - nothing saying that
the print could not be completed.  Removing laserWriter and laserPrep did
cause my mac to hang when I tried to print, but I restarted and
everything was fine.

Another option is that I could throw the field into the clipboard and
presumably use the printClip xcmd to print it - does this xcmd have
better error checking than printField?  I don't have this xcmd now,
but could probably get it from sumex or something.

Much thanks,
Joe Melvin
HyperCard Programmer
Carnegie Mellon University

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