parent(3p) | Perl Programmers Reference Guide | parent(3p)

# NAME

parent - Establish an ISA relationship with base classes at compile time

# SYNOPSIS

        package Baz;
        use parent qw(Foo Bar);

# DESCRIPTION

Allows you to both load one or more modules, while setting up inheritance from those modules at the same time. Mostly similar in effect to

        package Baz;
        BEGIN {
            require Foo;
            require Bar;
            push @ISA, qw(Foo Bar);
        }

By default, every base class needs to live in a file of its own. If you want to have a subclass and its parent class in the same file, you can tell "parent" not to load any modules by using the "-norequire" switch:

      package Foo;
      sub exclaim { "I CAN HAS PERL" }
      package DoesNotLoadFooBar;
      use parent -norequire, 'Foo', 'Bar';
      # will not go looking for Foo.pm or Bar.pm

This is equivalent to the following code:

      package Foo;
      sub exclaim { "I CAN HAS PERL" }
      package DoesNotLoadFooBar;
      push @DoesNotLoadFooBar::ISA, 'Foo', 'Bar';

This is also helpful for the case where a package lives within a differently named file:

      package MyHash;
      use Tie::Hash;
      use parent -norequire, 'Tie::StdHash';

This is equivalent to the following code:

      package MyHash;
      require Tie::Hash;
      push @ISA, 'Tie::StdHash';

If you want to load a subclass from a file that "require" would not consider an eligible filename (that is, it does not end in either ".pm" or ".pmc"), use the following code:

      package MySecondPlugin;
      require './plugins/custom.plugin'; # contains Plugin::Custom
      use parent -norequire, 'Plugin::Custom';

# HISTORY

This module was forked from base to remove the cruft that had accumulated in it.

# CAVEATS

# SEE ALSO

base
parent::versioned
  A fork of parent that provides version checking in parent class modules.

# AUTHORS AND CONTRIBUTORS

Rafaël Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern

# MAINTAINER

Max Maischein " corion@cpan.org "

Copyright (c) 2007-2017 Max Maischein "<corion@cpan.org>" Based on the idea of "base.pm", which was introduced with Perl 5.004_04.

# LICENSE

This module is released under the same terms as Perl itself.

2024-05-14 | perl v5.40.1