I don't quite understand what you mean when you say that the module is reloaded. Are you using Module::Reload or somesuch? A little more information about that would probably be helpful.

As for wrapping a subroutine you usually can use this format: 

my $old = \&IWL::Script::setScript;
*IWL::Script::setScript = sub {
  ...;
  goto &$old;
};

[download]
You assign to *IWL::Script::setScript at runtime, after you've saved away the old code in $old. Using goto here is good as your wrapper subroutine will be transparent to the original subroutine and not confuse it (or e.g. Carp). If you want to change a parameter you replace the element in @_ using push/pop, unshift/shift or splice or assign to @_ = .... You generally don't want to do $_[...] = ... because @_ is aliased. In your case you might want to do 
# Untested.

use Scalar::Util 'reftype';
use 5.010; # For ~~.

my $old = \&IWL::Script::setScript;
*setScript = sub {
  my ($self, $param) = @_;

  $param = $p2js->covert($param)
    if reftype($param) ~~ 'CODE';

  @_ = ($self, $param);

  # or:
  #splice @_, 1, 1, $p2js->convert($param)
  #  if reftype($param) ~~ 'CODE';

  goto &$old;
};

[download]

Hope this helps,
lodin

In reply to Re: Notification on module load, and redefinition of module methods. by lodin
in thread Notification on module load, and redefinition of module methods. by /dev/urandom

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