1MooseX::OneArgNew(3) User Contributed Perl Documentation MooseX::OneArgNew(3)
2
3
4
6 MooseX::OneArgNew - teach ->new to accept single, non-hashref arguments
7
9 version 0.005
10
12 In our class definition:
13
14 package Delivery;
15 use Moose;
16 with('MooseX::OneArgNew' => {
17 type => 'Existing::Message::Type',
18 init_arg => 'message',
19 });
20
21 has message => (isa => 'Existing::Message::Type', required => 1);
22
23 has to => (
24 is => 'ro',
25 isa => 'Str',
26 lazy => 1,
27 default => sub {
28 my ($self) = @_;
29 $self->message->get('To');
30 },
31 );
32
33 When making a message:
34
35 # The traditional way:
36
37 my $delivery = Delivery->new({ message => $message });
38 # or
39 my $delivery = Delivery->new({ message => $message, to => $to });
40
41 # With one-arg new:
42
43 my $delivery = Delivery->new($message);
44
46 MooseX::OneArgNew lets your constructor take a single argument, which
47 will be translated into the value for a one-entry hashref. It is a
48 parameterized role with three parameters:
49
50 type
51 The Moose type that the single argument must be for the one-arg
52 form to work. This should be an existing type, and may be either a
53 string type or a MooseX::Type.
54
55 init_arg
56 This is the string that will be used as the key for the hashref
57 constructed from the one-arg call to new.
58
59 coerce
60 If true, a single argument to new will be coerced into the expected
61 type if possible. Keep in mind that if there are no coercions for
62 the type, this will be an error, and that if a coercion from
63 HashRef exists, you might be getting yourself into a weird
64 situation.
65
66 WARNINGS
67 You can apply MooseX::OneArgNew more than once, but if more than one
68 application's type matches a single argument to "new", the behavior is
69 undefined and likely to cause bugs.
70
71 It would be a very bad idea to supply a type that could accept a normal
72 hashref of arguments to "new".
73
75 Ricardo Signes <rjbs@cpan.org>
76
78 · George Hartzell <hartzell@alerce.com>
79
80 · William Orr <will@worrbase.com>
81
83 This software is copyright (c) 2015 by Ricardo Signes.
84
85 This is free software; you can redistribute it and/or modify it under
86 the same terms as the Perl 5 programming language system itself.
87
88
89
90perl v5.32.0 2020-07-28 MooseX::OneArgNew(3)