Commit | Line | Data |
38bf2a25 |
1 | |
2 | package # hide the package from PAUSE |
3 | InstanceCountingClass; |
4 | |
5 | use strict; |
6 | use warnings; |
7 | |
8 | our $VERSION = '0.03'; |
9 | |
10 | use base 'Class::MOP::Class'; |
11 | |
12 | InstanceCountingClass->meta->add_attribute('count' => ( |
13 | reader => 'get_count', |
14 | default => 0 |
15 | )); |
16 | |
17 | InstanceCountingClass->meta->add_before_method_modifier('_construct_instance' => sub { |
18 | my ($class) = @_; |
19 | $class->{'count'}++; |
20 | }); |
21 | |
22 | 1; |
23 | |
24 | __END__ |
25 | |
26 | =pod |
27 | |
28 | =head1 NAME |
29 | |
30 | InstanceCountingClass - An example metaclass which counts instances |
31 | |
32 | =head1 SYNOPSIS |
33 | |
34 | package Foo; |
35 | |
36 | use metaclass 'InstanceCountingClass'; |
37 | |
38 | sub new { |
39 | my $class = shift; |
40 | $class->meta->new_object(@_); |
41 | } |
42 | |
43 | # ... meanwhile, somewhere in the code |
44 | |
45 | my $foo = Foo->new(); |
46 | print Foo->meta->get_count(); # prints 1 |
47 | |
48 | my $foo2 = Foo->new(); |
49 | print Foo->meta->get_count(); # prints 2 |
50 | |
51 | # ... etc etc etc |
52 | |
53 | =head1 DESCRIPTION |
54 | |
55 | This is a classic example of a metaclass which keeps a count of each |
56 | instance which is created. |
57 | |
58 | =head1 AUTHORS |
59 | |
60 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
61 | |
62 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
63 | |
64 | =head1 COPYRIGHT AND LICENSE |
65 | |
66 | Copyright 2006-2008 by Infinity Interactive, Inc. |
67 | |
68 | L<http://www.iinteractive.com> |
69 | |
70 | This library is free software; you can redistribute it and/or modify |
71 | it under the same terms as Perl itself. |
72 | |
73 | =cut |