在 Perl 中扩展 Class::Accessor 以在父 class 中设置一些属性

Question

我有一个 Class 定义为 Class::Accessor 像这样：

package Worker;
use Class::Accessor 'antlers';

# PROPS
has first_name      => ( is => 'rw' );
has position        => ( is => 'rw' );

# METHODS
sub print {
    my $self = shift;

    print "------------\n";
    print "Ref: ", ref $self, "\n";
    print "First Name: ", $self->first_name, "\n";

    if ($self->position) {
        print "Position: ", $self->position, "\n";
    }
}

1;

现在我想创建工程师 class 以属性始终设置为这样的方式扩展 Worker：position => 'Engineer' 例如：

package Engineer;
use Class::Accessor 'antlers';
use Worker;

extends(qw/Worker/);

# METHOS

sub new {
    return bless(__PACKAGE__->SUPER::new({position => 'Engineer'}));
}

1;

但这不起作用，因为当我像这样实例化工程师 class 时：

use Data::Dumper;
use strict;

# Relative Path to Class libraries
use FindBin;
use lib "$FindBin::Bin/.";

use Worker;
use Engineer;

my $wor = Worker->new({first_name => 'Matt'});
my $eng = Engineer->new({first_name => 'Ray'});
$wor->print;
$eng->print;

我在扩展 class 中松开 first_name 工程师：

------------
Ref: Worker
First Name: Matt
------------
Ref: Engineer
First Name: 
Position: Engineer

另一方面，我不确定覆盖 Engineer->new() 方法返回祝福是否是个好主意...

那么，我应该如何使用 Class::Accessor 扩展工人 class 以获得工程师 class？

Answer 1

这个新的覆盖似乎运行良好：

package Engineer;
use Class::Accessor 'antlers';
use Worker;
use Data::Dumper;

extends(qw/Worker/);

# METHODS

sub new {
    my($class) = shift;
    my $obj = __PACKAGE__->SUPER::new(@_);
    $obj->position('engineer');
    return bless $obj, $class;
}

Setter 和 getter 仍然适用于所有字段，'position' 字段在实例化对象时初始化。

在 Perl 中扩展 Class::Accessor 以在父 class 中设置一些属性

Extending a Class::Accessor in Perl to set some properties in parent class

perl

accessor