On 28/10/2010 7:41 AM, Lindley, Robert A wrote:
I made that temporary change to Tkx.pm and Tktable -variable worked with your
version of tie. However there is a conflict of interests here as illustrated by
the attached code. (Only works with your Tkx.pm patch.)
First, anything in the tied Perl hash is lost after the tie. Just noted because
if you know it is happening it is not a problem.
This is "by design" of tied variables. You want to instantiate and tie
before putting any data in.
Second, if one is using Tcl.pm elsewhere in the program the same named Tcl
variable resides in a different name space. It is not real neat to have more
than one Tcl interp object around. That is probably why the one inside Tkx.pm
is a private one.
Actually it is more subtle than that. You are actually creating
multiple Tcl interpreters (same as having multiple Perl interps). This
means it's not just hiding $interp in another namespace, it's an
entirely separate interpreter. Each is distinct with full interp context.
Jeff
-----Original Message-----
From: Jeff Hobbs [mailto:[email protected]]
Sent: Wednesday, October 27, 2010 6:37 PM
To: Lindley, Robert A; Gisle Aas; Tcl/Tk Mailing List
Subject: Re: How to use a tcl/tk widget that needs a tcl array
On 2010-10-22, at 10:01 AM, Lindley, Robert A wrote:
I would like to use the tktable widget, but can't find any information
on how to pass something as the -variable option and be able to
display and retrieve data.
use Tkx;
Tkx::package_require("Tktable");
my $mw = Tkx::widget->new(".");
my $t = $mw->new_table(
-rows => 5,
-cols => 3,
);
$t->g_pack;
Tkx::MainLoop()
I found the above in the ActiveState documentation. It works as expected.
All attempts to display or retrieve data have failed.
So in working with Bob to address this, I found that there is a key
missing feature in Tkx to support the final solution - obtaining the
$interp used by Tkx.
My first point was that the table by default needs a data source. The
easiest is to use '-cache => 1' to say cache data in memory. To tie it
to a hash, you need to use tie and reference the tied name in Tcl (.e.g
-variable => 'myarray'). It turns out the docs for Tcl.pm are incorrect
in not quoting Tcl::Var, but it would look like this:
tie %hash, 'Tcl::Var', $interp, "myarray";
The real problem though is how do you get $interp from Tkx? It looks
like you don't. It's a 'my' var in Tkx::i namespace, and the rest of
the package handily abstracts everything so neatly that you don't need
access to $interp. EXCEPT in this one case. I patched Tkx to have
sub interp { return $interp; }
in the Tkx::i namespace, which would allow:
tie %hash, 'Tcl::Var', Tkx::i::interp(), "myarray";
and checked that this does work with the attached sources. The question
is, is this the correct answer? Should Tkx have a different redirect
for 'tie', or should there be another way to get the $interp reference
that Tkx uses?
Gisle - any thoughts on this?
Jeff
