1Moose::Meta::Attribute:U:sNeartiCvoen(t3r)ibuted Perl DoMcouomseen:t:aMteitoan::Attribute::Native(3)
2
6 Moose::Meta::Attribute::Native - Delegate to native Perl types
7
9 version 2.2201
10
12 package MyClass;
13 use Moose;
14 has 'mapping' => (
16 traits => ['Hash'],
17 is => 'rw',
18 isa => 'HashRef[Str]',
19 default => sub { {} },
20 handles => {
21 exists_in_mapping => 'exists',
22 ids_in_mapping => 'keys',
23 get_mapping => 'get',
24 set_mapping => 'set',
25 set_quantity => [ set => 'quantity' ],
26 },
27 );
28 my $obj = MyClass->new;
30 $obj->set_quantity(10); # quantity => 10
31 $obj->set_mapping('foo', 4); # foo => 4
32 $obj->set_mapping('bar', 5); # bar => 5
33 $obj->set_mapping('baz', 6); # baz => 6
34 # prints 5
36 print $obj->get_mapping('bar') if $obj->exists_in_mapping('bar');
37 # prints 'quantity, foo, bar, baz'
39 print join ', ', $obj->ids_in_mapping;
40
42 Native delegations allow you to delegate to native Perl data structures
43 as if they were objects. For example, in the "SYNOPSIS" you can see a
44 hash reference being treated as if it has methods named "exists()",
45 "keys()", "get()", and "set()".
46 The delegation methods (mostly) map to Perl builtins and operators. The
48 return values of these delegations should be the same as the
49 corresponding Perl operation. Any deviations will be explicitly
50 documented.
51
53 Native delegations are enabled by passing certain options to "has" when
54 creating an attribute.
55 traits
57 To enable this feature, pass the appropriate name in the "traits" array
58 reference for the attribute. For example, to enable this feature for
59 hash reference, we include 'Hash' in the list of traits.
60 isa
62 You will need to make sure that the attribute has an appropriate type.
63 For example, to use this with a Hash you must specify that your
64 attribute is some sort of "HashRef".
65 handles
67 This is just like any other delegation, but only a hash reference is
68 allowed when defining native delegations. The keys are the methods to
69 be created in the class which contains the attribute. The values are
70 the methods provided by the associated trait. Currying works the same
71 way as it does with any other delegation.
72 See the docs for each native trait for details on what methods are
74 available.
75
77 Below are some simple examples of each native trait. More features are
78 available than what is shown here; this is just a quick synopsis.
79 Array (Moose::Meta::Attribute::Native::Trait::Array)
81 has 'queue' => (
82 traits => ['Array'],
83 is => 'ro',
84 isa => 'ArrayRef[Str]',
85 default => sub { [] },
86 handles => {
87 add_item => 'push',
88 next_item => 'shift',
89 # ...
90 }
91 );
92 Bool (Moose::Meta::Attribute::Native::Trait::Bool)
94 has 'is_lit' => (
95 traits => ['Bool'],
96 is => 'ro',
97 isa => 'Bool',
98 default => 0,
99 handles => {
100 illuminate => 'set',
101 darken => 'unset',
102 flip_switch => 'toggle',
103 is_dark => 'not',
104 # ...
105 }
106 );
107 Code (Moose::Meta::Attribute::Native::Trait::Code)
109 has 'callback' => (
110 traits => ['Code'],
111 is => 'ro',
112 isa => 'CodeRef',
113 default => sub {
114 sub {'called'}
115 },
116 handles => {
117 call => 'execute',
118 # ...
119 }
120 );
121 Counter (Moose::Meta::Attribute::Native::Trait::Counter)
123 has 'counter' => (
124 traits => ['Counter'],
125 is => 'ro',
126 isa => 'Num',
127 default => 0,
128 handles => {
129 inc_counter => 'inc',
130 dec_counter => 'dec',
131 reset_counter => 'reset',
132 # ...
133 }
134 );
135 Hash (Moose::Meta::Attribute::Native::Trait::Hash)
137 has 'options' => (
138 traits => ['Hash'],
139 is => 'ro',
140 isa => 'HashRef[Str]',
141 default => sub { {} },
142 handles => {
143 set_option => 'set',
144 get_option => 'get',
145 has_option => 'exists',
146 # ...
147 }
148 );
149 Number (Moose::Meta::Attribute::Native::Trait::Number)
151 has 'integer' => (
152 traits => ['Number'],
153 is => 'ro',
154 isa => 'Int',
155 default => 5,
156 handles => {
157 set => 'set',
158 add => 'add',
159 sub => 'sub',
160 mul => 'mul',
161 div => 'div',
162 mod => 'mod',
163 abs => 'abs',
164 # ...
165 }
166 );
167 String (Moose::Meta::Attribute::Native::Trait::String)
169 has 'text' => (
170 traits => ['String'],
171 is => 'ro',
172 isa => 'Str',
173 default => q{},
174 handles => {
175 add_text => 'append',
176 replace_text => 'replace',
177 # ...
178 }
179 );
180
182 This feature used to be a separated CPAN distribution called
183 MooseX::AttributeHelpers.
184 When the feature was incorporated into the Moose core, some of the API
186 details were changed. The underlying capabilities are the same, but
187 some details of the API were changed.
188
190 See "BUGS" in Moose for details on reporting bugs.
191
193 • Stevan Little <stevan@cpan.org>
194 • Dave Rolsky <autarch@urth.org>
196 • Jesse Luehrs <doy@cpan.org>
198 • Shawn M Moore <sartak@cpan.org>
200 • יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
202 • Karen Etheridge <ether@cpan.org>
204 • Florian Ragwitz <rafl@debian.org>
206 • Hans Dieter Pearcey <hdp@cpan.org>
208 • Chris Prather <chris@prather.org>
210 • Matt S Trout <mstrout@cpan.org>
212
214 This software is copyright (c) 2006 by Infinity Interactive, Inc.
215 This is free software; you can redistribute it and/or modify it under
217 the same terms as the Perl 5 programming language system itself.
218perl v5.34.0 2022-01-21 Moose::Meta::Attribute::Native(3)