"Connecting" 一个带有哈希的 Moo 对象

Question

在我的真实代码中，我想 "synchronize" 一个带有散列（实际上是绑定散列）的 Moo（如果 Moo 不起作用，则为 Moose）对象，以便读取属性 Moo 对象的属性将从散列中读取相应的值并写入 Moo 对象的属性将存储到散列中。

以下为简化代码：

#!/usr/bin/perl

use feature qw(say);

package X;
use Moo;
use Data::Dumper;

my $BusinessClass = 'X';

has 'base' => (is => 'rw', builder => 'base_builder');

sub base_builder {
  return {};
}

foreach my $Key (qw(a b c)) {
  {
    no strict 'refs';
    *{"${BusinessClass}::$Key"} = sub {
      if (@_ == 2) {
        return $_[0]->base->{$Key} = $_[1];
      } else {
        return $_[0]->base->{$Key};
      }
    };
    has $Key => ( is        => 'rw',
                  lazy      => 0,
                  required  => 0,
                  reader => "${BusinessClass}::_access1_$Key",
                  writer => "${BusinessClass}::_access2_$Key",
                );
  }
}

my $obj = X->new(a=>123, b=>456);
print Dumper $obj->base;
$obj->c(789);
print Dumper $obj->base;

问题是传递给 new 函数的属性没有存储在 has $obj->base 中（但它们应该是）。在上面的代码示例中，属性 c 被正确存储，但 a 和 b 没有存储到散列中。这是一个错误。

处理这种情况的好方法是什么？

Answer 1

这可以通过添加来解决：

sub BUILD {
  my ($self, $args) = @_;

  foreach my $Key (keys %$args) {
    $self->base->{$Key} = $args->{$Key};
    my $clearer = "_clear_local_$Key";
    $self->$clearer();
  }
}

完整代码：

#!/usr/bin/perl

use feature qw(say);

package X;
use Moo;
use Data::Dumper;

my $BusinessClass = 'X';

has 'base' => (is => 'rw', builder => 'base_builder');

sub base_builder {
  return {};
}

sub BUILD {
  my ($self, $args) = @_;

  foreach my $Key (keys %$args) {
    $self->base->{$Key} = $args->{$Key};
    my $clearer = "_clear_local_$Key";
    $self->$clearer();
  }
}

foreach my $Key (qw(a b c)) {
  {
    no strict 'refs';
    *{"${BusinessClass}::$Key"} = sub {
      if (@_ == 2) {
        return $_[0]->base->{$Key} = $_[1];
      } else {
        return $_[0]->base->{$Key};
      }
    };
    has $Key => ( is        => 'rw',
                  lazy      => 0,
                  required  => 0,
                  reader => "${BusinessClass}::_access1_$Key",
                  writer => "${BusinessClass}::_access2_$Key",
                  clearer => "_clear_local_$Key",
                );
  }
}

my $obj = X->new(a=>123, b=>456);
print Dumper $obj->base;
$obj->c(789);
print Dumper $obj->base;

print Dumper {%$obj};

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