perl - 如何将函数传递给构造函数

Question

如何将函数传递给构造函数，以便类可以在内部使用它？

测试.pl

use Class;
use Loger;

my $loger = Loger->new();
$loger->log('I have logger now, I can log messages!');

my $class = Class->new(\&{ $loger->log }); # here we pass the function (the method of other class) to contructor of a new  Class

$class->do_something();  # class uses loger->log internally to report errors

Class.pm 包类；

sub new {

    my $self = {};
    $self->{log} = shift; # we got logger->log function, save it for future use

    return bless $self;
}

sub do_something {
     my $self = shift;

     open_file or $self->{log}->('Cant open file'); # we can use gotten logger in class 
}


1;

Answer 1

您正在尝试传递方法，而不是函数(或子函数)。单独调用它是行不通的。如果你想要一个对象的方法，传递对象并调用对象上的方法。

my $loger = Loger->new();
$loger->log('I have logger now, I can log messages!');

my $class = Class->new(logger => $loger); # pass the Loger object

在 Class.pm 中:

package Class;

sub new
{
  my ($class, %args) = @_;
  my $self = {};
  $self->{log} = $args{'logger'}; # store it inside your Class object
  return bless $self;
}

sub do_something
{
   my $self = shift;
   open_file or $self->{log}->log->('Cant open file'); # call its log-method
}