Re: Tk save variables into a file and load

[zentara]

Hi, I don't know about your code problem, but as to your original question:
I need help in perl Tk to save, load, default or change config variables, whenever i require. How do I approach.

One good way is to use Storable. It allows you to write an existing hash to a file, OR read the file back into a hash.

Here is some code showing it's basic use. For further info see ztkdb where I use this technique.

use Tk;
use Storable;

# Say your config information is in notebook.db
# and your config hash is %info.
# At startup check if notebook.db exists and load it
# into your config hash. If it dosn't exist then it means it's the
# first run of the program and do something to make the notebook.db

my %info; # global hash to hold your data

if(-e 'notebook.db'){
    %info = %{retrieve('notebook.db')};   # direct to hash
    }else{ make_notebook() }


# now in your program, as you change things and want to
# store them to the notebook.db, you need to save it.
# Here is a list of Tk related statements that will automatically
# save your notebook.db  whenever you exit the program

#setup auto save of storable db
$mw->protocol('WM_DELETE_WINDOW' => sub { &save_it() });
$SIG{__DIE__} = sub { &save_it()};
$SIG{INT} = sub { &save_it()};
$mw->bind('<Control-c>', [sub{&save_it(); Tk::exit;}] );

# and the save_it sub

sub save_it{
   store(\%info,'notebook.db');
   print "saved\n";
}

[afoken]

I need help in perl Tk to save, load, default or change config variables, whenever i require. How do I approach.

One good way is to use Storable. It allows you to write an existing hash to a file, OR read the file back into a hash.

I would use Storable only for short-time data storage (i.e. temporary files that survive only for seconds up to hours) on a single machine. Here is why: Re: Perl Storable problem (i Think).

There are much better ways for long-time data storage and configuration files: Re: Accessing variables in an external hash without eval.

And for storing more than a few kBytes worth of data, perhaps across several machines, there is DBI and the various supported databases: Re^2: Perl and Database.

Alexander