File::Find::Object::Rule::Extending - the mini-guide to extending File::Find::Object::Rule |
File::Find::Object::Rule::Extending - the mini-guide to extending File::Find::Object::Rule
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;
the File::Find::Object::Rule manpage inherits the File::Find::Rule manpage's extensibility. It is now possibile to extend it, using the following conventions.
package File::Find::Object::Rule::Random;
use strict; use warnings;
# 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.
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 random
with a null prototype it would have
consumed in
as a parameter to it, then got all confused as it
doesn't know about a '.'
rule.
The callback can access the the File::Find::Object::Result manpage using
$self->finder->item_obj()
.
Richard Clamp <richardc@unixbeard.net>
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.
the File::Find::Object::Rule manpage
the File::Find::::Rule::MMagic manpage was the first extension module for the File::Find::Rule manpage, so maybe check that out.
File::Find::Object::Rule::Extending - the mini-guide to extending File::Find::Object::Rule |