1MooseX::LazyRequire(3)User Contributed Perl DocumentationMooseX::LazyRequire(3)
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NAME

6       MooseX::LazyRequire - Required attributes which fail only when trying
7       to use them
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SYNOPSIS

10           package Foo;
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12           use Moose;
13           use MooseX::LazyRequire;
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15           has foo => (
16               is            => 'ro',
17               lazy_required => 1,
18           );
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20           has bar => (
21               is      => 'ro',
22               builder => '_build_bar',
23           );
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25           sub _build_bar { shift->foo }
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27
28           Foo->new(foo => 42); # succeeds, foo and bar will be 42
29           Foo->new(bar => 42); # succeeds, bar will be 42
30           Foo->new;            # fails, neither foo nor bare were given
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DESCRIPTION

33       This module adds a "lazy_required" option to Moose attribute
34       declarations.
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36       The reader methods for all attributes with that option will throw an
37       exception unless a value for the attributes was provided earlier by a
38       constructor parameter or through a writer method.
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CAVEATS

41       Apparently Moose roles don't have an attribute metaclass, so this
42       module can't easily apply its magic to attributes defined in roles. If
43       you want to use "lazy_required" in role attributes, you'll have to
44       apply the attribute trait yourself:
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46           has foo => (
47               traits        => ['LazyRequire'],
48               is            => 'ro',
49               lazy_required => 1,
50           );
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AUTHOR

53       Florian Ragwitz <rafl@debian.org>
54

56       This software is copyright (c) 2010 by Florian Ragwitz.
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58       This is free software; you can redistribute it and/or modify it under
59       the same terms as the Perl 5 programming language system itself.
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63perl v5.12.1                      2010-07-19            MooseX::LazyRequire(3)
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