1Sub::HandlesVia::ManualU:s:eWritChoGnetnreirbiuct(e3d)PSeurbl::DHoacnudmleenstVaitai:o:nManual::WithGeneric(3)
2
3
4

NAME

6       Sub::HandlesVia::Manual::WithGeneric - using Sub::HandlesVia with
7       generic Perl classes
8

MANUAL

10       Sub::HandlesVia allows you to delegate methods from your class to the
11       values of your objects' attributes.
12
13       Conceptually, it allows you to define "$object->push_number($n)" to be
14       a shortcut for "$object->numbers->push($n)" except that
15       "$object->numbers" is an arrayref, so doesn't have methods you can call
16       on it like "push".
17
18       For Moose and Mouse, Sub::HandlesVia can use their metaobject protocols
19       to grab an attribute's definition and install the methods it needs to.
20       For Moo, it can wrap "has" and do its stuff that way. For other
21       classes, you need to be more explicit and tell it what methods to
22       delegate to what attributes.
23
24        package Kitchen {
25
26          # constructor
27          sub new {
28            my ( $class, %arg ) = @_;
29            $arg{food} ||= [];
30            return bless( \%arg, $class );
31          }
32
33          # getter/setter for `food`
34          sub food {
35            (@_ == 1) ? $_[0]{food} : ( $_[0]{food} = $_[1] );
36          }
37
38          use Sub::HandlesVia qw( delegations );
39
40          delegations(
41            attribute   => 'food'
42            handles_via => 'Array',
43            handles     => {
44              'add_food'    => 'push',
45              'find_food'   => 'grep',
46            },
47          );
48        }
49
50       Setting "attribute" to "food" means that when Sub::HandlesVia needs to
51       get the food list, it will call "$kitchen->food" and when it needs to
52       set the food list, it will call "$kitchen->food($value)".  If you have
53       separate getter and setter methods, just do:
54
55            attribute   => [ 'get_food', 'set_food' ],
56
57       Or if you don't have any accessors and want Sub::HandlesVia to directly
58       access the underlying hashref:
59
60            attribute   => '{food}',
61
62       Or maybe you have a setter, but want to use hashref access for the
63       getter:
64
65            attribute   => [ '{food}', 'set_food' ],
66
67       Or maybe you still want direct access for the getter, but your object
68       is a blessed arrayref instead of a blessed hashref:
69
70            attribute   => [ '[7]', 'set_food' ],
71
72       Or maybe your needs are crazy unique:
73
74            attribute   => [ \&getter, \&setter ],
75
76       The coderefs are passed the instance as their first argument, and the
77       setter is also passed a value to set.
78
79       Really, I don't think there's any object system that this won't work
80       for!
81
82       If you supply an arrayref with a getter and setter, it's also possible
83       to supply a third argument which is a coderef or string which will be
84       called as a method if needing to "reset" the value.  This can be
85       thought of like a default or builder.
86
87       (The "delegations" function can be imported into Moo/Mouse/Moose
88       classes too, in which case the "attribute" needs to be the same
89       attribute name you passed to "has". You cannot use a arrayref, coderef,
90       hash key, or array index.)
91

BUGS

93       Please report any bugs to
94       <https://github.com/tobyink/p5-sub-handlesvia/issues>.
95

SEE ALSO

97       Misc advanced documentation: Sub::HandlesVia::Manual::Advanced.
98
99       Sub::HandlesVia.
100
101       Documentation for delegatable methods:
102       Sub::HandlesVia::HandlerLibrary::Array,
103       Sub::HandlesVia::HandlerLibrary::Blessed,
104       Sub::HandlesVia::HandlerLibrary::Bool,
105       Sub::HandlesVia::HandlerLibrary::Code,
106       Sub::HandlesVia::HandlerLibrary::Counter,
107       Sub::HandlesVia::HandlerLibrary::Hash,
108       Sub::HandlesVia::HandlerLibrary::Number,
109       Sub::HandlesVia::HandlerLibrary::Scalar, and
110       Sub::HandlesVia::HandlerLibrary::String.
111

AUTHOR

113       Toby Inkster <tobyink@cpan.org>.
114

116       This software is copyright (c) 2022 by Toby Inkster.
117
118       This is free software; you can redistribute it and/or modify it under
119       the same terms as the Perl 5 programming language system itself.
120

DISCLAIMER OF WARRANTIES

122       THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
123       WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
124       MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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128perl v5.36.0                      2022-1S2u-b1:7:HandlesVia::Manual::WithGeneric(3)
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