move core meta-attribute attributes to a mixin class for benefit of role attributes
[gitmo/Class-MOP.git] / lib / Class / MOP / Mixin / AttributeBase.pm
1 package Class::MOP::Mixin::AttributeBase;
2
3 use strict;
4 use warnings;
5
6 use Scalar::Util 'blessed';
7
8 our $VERSION = '0.97';
9 $VERSION = eval $VERSION;
10 our $AUTHORITY = 'cpan:STEVAN';
11
12 use base 'Class::MOP::Object';
13
14 sub has_accessor        { defined $_[0]->{'accessor'} }
15 sub has_reader          { defined $_[0]->{'reader'} }
16 sub has_writer          { defined $_[0]->{'writer'} }
17 sub has_predicate       { defined $_[0]->{'predicate'} }
18 sub has_clearer         { defined $_[0]->{'clearer'} }
19 sub has_builder         { defined $_[0]->{'builder'} }
20 sub has_init_arg        { defined $_[0]->{'init_arg'} }
21 sub has_default         { defined $_[0]->{'default'} }
22 sub has_initializer     { defined $_[0]->{'initializer'} }
23 sub has_insertion_order { defined $_[0]->{'insertion_order'} }
24
25 sub accessor             { $_[0]->{'accessor'} }
26 sub reader               { $_[0]->{'reader'} }
27 sub writer               { $_[0]->{'writer'} }
28 sub predicate            { $_[0]->{'predicate'} }
29 sub clearer              { $_[0]->{'clearer'} }
30 sub builder              { $_[0]->{'builder'} }
31 sub init_arg             { $_[0]->{'init_arg'} }
32 sub initializer          { $_[0]->{'initializer'} }
33 sub definition_context   { $_[0]->{'definition_context'} }
34 sub insertion_order      { $_[0]->{'insertion_order'} }
35 sub _set_insertion_order { $_[0]->{'insertion_order'} = $_[1] }
36
37 sub has_read_method  { $_[0]->has_reader || $_[0]->has_accessor }
38 sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
39
40 sub is_default_a_coderef {
41     # Uber hack because it is called from CMOP::Attribute constructor as
42     # $class->is_default_a_coderef(\%options)
43     my ($value) = ref $_[0] ? $_[0]->{'default'} : $_[1]->{'default'};
44
45     return unless ref($value);
46
47     return ref($value) eq 'CODE'
48         || ( blessed($value) && $value->isa('Class::MOP::Method') );
49 }
50
51 sub default {
52     my ( $self, $instance ) = @_;
53     if ( defined $instance && $self->is_default_a_coderef ) {
54         # if the default is a CODE ref, then we pass in the instance and
55         # default can return a value based on that instance. Somewhat crude,
56         # but works.
57         return $self->{'default'}->($instance);
58     }
59     $self->{'default'};
60 }
61
62 1;