I've been trying, without success, to write an Apple Event library for
Perl that will allow my Perl Tkx apps to respond to and send Apple
Events. (Apple Events are a form of IPC on the Mac that allows native
apps to communicate with each other, exchange data, and even drive other
apps--somewhat analogous to COM or DDE on Windows.) Perl's C API is very
gnarly and so is the Apple Events API from C, and so I've made little
progress there. There is a long-established support for Apple Events in
the Mac::Carbon module at CPAN, but this module does not support 64-bit
(Apple has deprecated many of the API's the module wraps) and its author
is disinclined to update it, instead advising users to simply run Perl
as a 32-bit app--not a viable option for me.
As a result, I have turned to a native Tcl library that integrates with
the Apple Event API, tclAE (http://tclae.sourceforge.net). I've used
this library directly from Tcl with no problem, and would like to use
Tkx's integration to use it in my Perl Tk apps as well. However, thus
far I have not had success.
tclAE works by allowing you to register specific Apple Events with the
system and to register an internal Tcl command that implements the Apple
Event functionality. (Externally the command is mapped to an AppleScript
command that is registered elsewhere.) Doing this via Tkx, I have
started with this command:
Tkx::tclAE__installEventHandler ("Perl", "hihi", "perl::hello");
"Perl" and "hihi" are the Apple Event fields (they are arbitrary
four-char fields) and "perl::hello" is the internal subroutine that
responds to the command. That should work, but when I actually run an
AppleScript command targeting my test app, I get this error:
perlapp got an error: invalid command name "perl::hello"
That error string means that it's a non-existent Tcl command.
Here is where I am not sure if I am doing things correctly. I am
exposing the Perl command to the Tcl interpreter by defining it thus as
a Perl subroutine:
sub tcl::hello (theAppleEvent theReturnAE)
and then exporting it thus:
my $tcl = Tcl->new;
$tcl->export_to_tcl(subs_from=>'tcl', vars_from=>'tcl');
This seems to provide the cleanest and simplest mapping between Perl
subroutines and Tcl commands. I am also aware that I can define the
command as this:
$tcl->CreateCommand(hello, \&hello):
Is one method better than the other?
In any event, tclAE is not picking up on the Tcl command I'm passing to
the Tcl interpreter, and I believe it should. Can anyone suggest how I
can get this command exposed cleanly to the Tcl interpreter if I am not
doing it correctly?
--Kevin
--
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
http://www.wtmobilesoftware.com
