Commit | Line | Data |
8eec3c69 |
1 | package MooseX::Singleton::Role::Meta::Class; |
2 | use Moose::Role; |
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3 | use MooseX::Singleton::Role::Meta::Instance; |
4 | use MooseX::Singleton::Role::Meta::Method::Constructor; |
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5 | |
6 | our $VERSION = '0.21'; |
7 | $VERSION = eval $VERSION; |
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8 | |
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9 | sub existing_singleton { |
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10 | my ($class) = @_; |
11 | my $pkg = $class->name; |
12 | |
13 | no strict 'refs'; |
14 | |
15 | # create exactly one instance |
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16 | if ( defined ${"$pkg\::singleton"} ) { |
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17 | return ${"$pkg\::singleton"}; |
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18 | } |
19 | |
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20 | return; |
21 | } |
22 | |
03e1b8df |
23 | sub clear_singleton { |
24 | my ($class) = @_; |
25 | my $pkg = $class->name; |
26 | no strict 'refs'; |
27 | undef ${"$pkg\::singleton"}; |
28 | } |
29 | |
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30 | override _construct_instance => sub { |
1de95613 |
31 | my ($class) = @_; |
32 | |
33 | # create exactly one instance |
34 | my $existing = $class->existing_singleton; |
35 | return $existing if $existing; |
36 | |
37 | my $pkg = $class->name; |
38 | no strict 'refs'; |
39 | return ${"$pkg\::singleton"} = super; |
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40 | }; |
41 | |
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42 | no Moose::Role; |
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43 | |
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44 | 1; |
45 | |
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46 | __END__ |
47 | |
48 | =pod |
49 | |
50 | =head1 NAME |
51 | |
8eec3c69 |
52 | MooseX::Singleton::Role::Meta::Class - Metaclass role for MooseX::Singleton |
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53 | |
54 | =head1 DESCRIPTION |
55 | |
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56 | This metaclass role makes sure that there is only ever one instance of an |
57 | object for a singleton class. The first call to C<construct_instance> is run |
58 | normally (and then cached). Subsequent calls will return the cached version. |
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59 | |
60 | =cut |
61 | |