=head1 NAME File::Find::Object::Rule::Extending - the mini-guide to extending File::Find::Object::Rule =head1 SYNOPSIS package File::Find::Object::Rule::Random; use strict; use warnings; # take useful things from File::Find::Object::Rule use base 'File::Find::Object::Rule'; # and force our crack into the main namespace sub File::Find::Object::Rule::random () { my $self = shift()->_force_object; $self->exec( sub { rand > 0.5 } ); } 1; =head1 DESCRIPTION L inherits L's extensibility. It is now possibile to extend it, using the following conventions. =head2 Declare your package package File::Find::Object::Rule::Random; use strict; use warnings; =head2 Inherit methods from File::Find::Object::Rule # take useful things from File::Find::Object::Rule use base 'File::Find::Object::Rule'; =head3 Force your madness into the main package # and force our crack into the main namespace sub File::Find::Object::Rule::random () { my $self = shift()->_force_object; $self->exec( sub { rand > 0.5 } ); } Yes, we're being very cavalier here and defining things into the main File::Find::Object::Rule namespace. This is due to lack of imaginiation on my part - I simply can't find a way for the functional and oo interface to work without doing this or some kind of inheritance, and inheritance stops you using two File::Find::Object::Rule::Foo modules together. For this reason try and pick distinct names for your extensions. If this becomes a problem then I may institute a semi-official registry of taken names. =head2 Taking no arguments. Note the null prototype on random. This is a cheat for the procedural interface to know that your sub takes no arguments, and so allows this to happen: find( random => in => '.' ); If you hadn't declared C with a null prototype it would have consumed C as a parameter to it, then got all confused as it doesn't know about a C<'.'> rule. =head1 NOTES ABOUT THE CALLBACK The callback can access the L using C<<< $self->finder->item_obj() >>>. =head1 AUTHOR Richard Clamp =head1 COPYRIGHT Copyright (C) 2002 Richard Clamp. All Rights Reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =head1 SEE ALSO L L was the first extension module for L, so maybe check that out. =cut