in reply to calling methods using a variable

Here's a quick replication of your problem:

use strict;
use CGI;
my $q = CGI->new;

my $good_method = "param";
my $bad_method = "param('foo')";
print $q->$good_method( 'foo' );
print $q->$bad_method;

[download]

To fix it, make an array of array refs with the second item being your arguments:

@commands = (
  ['add_node','W1'],
  ['add_node','W2'],
  ['add_edge,'W2' => 'W1']
);

use GraphViz;
my $g = GraphViz->new();
foreach (@commands) {
    my ( $command, @args ) = @$_;
    $g->$command( @args );
}

[download]

Cheers,
Ovid

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Replies are listed 'Best First'.
Re: Re: calling methods using a variable
by Kanji (Parson) on Mar 22, 2002 at 00:48 UTC

    It would also prudent to throw a next unless $g->can($command); or something in there so that things don't go bewm if $command doesn't exist (ie, someone made a tipo [sic.]).

    You might even want to throw in some security checks for good measure...

    foreach (@commands) {
    my ( $command, @args ) = @$_;

    warn("Naughty, $command not allowed..."), next 
      unless $permitted{$command};

    warn("Ooops, I can't find $command..."), next
      unless $g->can($command);

    $g->$command( @args );
}

    [download]

        --k.


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