arrays - Moose 阵列属性 : how do I use a set method?

Question

我想定义一个数组作为类的属性，并在类实例化时用一些数据填充它。

我认为可以使用 $self->attribute->set($id, $value)方法以便在给定索引上设置元素。至少这是我从驼鹿身上了解到的documentation .

但是当我尝试

use Data::Dumper qw( Dumper );
use Moose;

has cells => (
    is => 'rw',
    traits  => ['Array'],
    isa     => 'ArrayRef',
    default => sub { [] },
);

my $app = __PACKAGE__->new();
$app->cells->set($_, $_) for 0..3;
print(Dumper($app->cells));

我得到

Can't call method "set" on unblessed reference

我该怎么做 set工作？

Answer 1

use Data::Dumper qw( Dumper );
use Moose;

has cells => (
    is => 'rw',
    traits  => ['Array'],
    isa     => 'ArrayRef',
    default => sub { [] },
    handles => {                   # <---
       set_cell => 'set',          # <---
    },                             # <---
);

my $app = __PACKAGE__->new();
$app->set_cell($_, $_) for 0..3;   # <---
print(Dumper($app->cells));

尽管评论中有相反的说法，但它在 BUILD 中运行良好也。

use Data::Dumper qw( Dumper );
use Moose;

has cells => (
    is => 'rw',
    traits  => ['Array'],
    isa     => 'ArrayRef',
    default => sub { [] },
    handles => {
       set_cell => 'set',
    },
);

sub BUILD {
    my ($self) = @_;
    $self->set_cell($_, $_) for 0..3;
}

my $app = __PACKAGE__->new();
print(Dumper($app->cells));