File Coverage

blib/lib/MoobX/Trait/Observer.pm
Criterion Covered Total %
statement 9 9 100.0
branch n/a
condition n/a
subroutine 3 3 100.0
pod n/a
total 12 12 100.0


line stmt bran cond sub pod time code
1             our $AUTHORITY = 'cpan:YANICK';
2             # ABSTRACT: turn a Moose attribute into a MoobX observer
3             $MoobX::Trait::Observer::VERSION = '0.1.2';
4              
5             use Moose::Role;
6 8     8   7272 use MoobX::Observer;
  8         37201  
  8         39  
7 8     8   41563  
  8         19  
  8         282  
8             use experimental 'signatures';
9 8     8   46  
  8         12  
  8         65  
10             Moose::Util::meta_attribute_alias('Observer');
11              
12             before _process_options => sub {
13             my( $self, $name, $args) = @_;
14              
15             my $gen = $args->{default};
16              
17             $args->{lazy} //= 1;
18              
19             $args->{default} = sub {
20             my @args = @_;
21             MoobX::Observer->new(
22             generator => sub { $gen->(@args) },
23             autorun => !$args->{lazy},
24             )
25             };
26            
27             };
28              
29             1;
30              
31              
32             =pod
33              
34             =encoding UTF-8
35              
36             =head1 NAME
37              
38             MoobX::Trait::Observer - turn a Moose attribute into a MoobX observer
39              
40             =head1 VERSION
41              
42             version 0.1.2
43              
44             =head1 SYNOPSIS
45              
46             package Person;
47              
48             use MoobX;
49              
50             our $OPENING :Observable = 'Dear';
51              
52             has name => (
53             traits => [ 'Observable' ],
54             is => 'rw',
55             );
56              
57             has address => (
58             is => 'ro',
59             traits => [ 'Observer' ],
60             default => sub {
61             my $self = shift;
62             join ' ', $Person::OPENING, $self->name
63             },
64             );
65              
66             my $person = Person->new( name => 'Wilfred' );
67              
68             print $person->address; # Dear Wilfred
69              
70             $Person::OPENING = 'My very dear';
71              
72             print $person->address; # My very dear Wilfred
73              
74             =head1 DESCRIPTION
75              
76             Turns an object attribute into an observer. The C<default> argument
77             is used as the value-generating function.
78              
79             By default the attribute will be considered to be lazy.
80             If the C<lazy> attribute is explicitly
81             set to C<false>, then the observer will be of the C<autorun>
82             variety. Be careful, though, as it'll probably not do what you want if you
83             observe other attributes.
84              
85             package MyThing;
86              
87             use MoobX;
88              
89             has foo => (
90             is => [ 'Observable' ],
91             );
92              
93             has bar => (
94             is => [ 'Observer' ],
95             lazy => 0,
96             default => sub {
97             my $self = shift;
98              
99             # OOPS! If 'bar' is processed before 'foo'
100             # at the object init stage, `$self->foo`
101             # will not be an observable yet, so `bar`
102             # will be set to be `1` and never react to anything
103             $self->foo + 1;
104             },
105             );
106              
107             =head1 AUTHOR
108              
109             Yanick Champoux <yanick@cpan.org>
110              
111             =head1 COPYRIGHT AND LICENSE
112              
113             This software is copyright (c) 2022, 2017 by Yanick Champoux.
114              
115             This is free software; you can redistribute it and/or modify it under
116             the same terms as the Perl 5 programming language system itself.
117              
118             =cut