projekt kivitendo

package parent;

use strict;

use vars qw($VERSION);

$VERSION = '0.221';

sub import {

    my $class = shift;

    my $inheritor = caller(0);

    if ( @_ and $_[0] eq '-norequire' ) {

        shift @_;

    } else {

        for ( my @filename = @_ ) {

            if ( $_ eq $inheritor ) {

                warn "Class '$inheritor' tried to inherit from itself\n";

            };

            s{::|'}{/}g;

            require "$_.pm"; # dies if the file is not found

        }

    }

    {

        no strict 'refs';

        # This is more efficient than push for the new MRO

        # at least until the new MRO is fixed

        @{"$inheritor\::ISA"} = (@{"$inheritor\::ISA"} , @_);

    };

};

"All your base are belong to us"

__END__

=head1 NAME

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

=head1 SYNOPSIS

    package Baz;

    use parent qw(Foo Bar);

=head1 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 C<parent> not to load any modules by using the C<-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';

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 C<require> would

not consider an eligible filename (that is, it does not end in

either C<.pm> or C<.pmc>), use the following code:

  package MySecondPlugin;

  require './plugins/custom.plugin'; # contains Plugin::Custom

  use parent -norequire, 'Plugin::Custom';

=head1 DIAGNOSTICS

=over 4

=item Class 'Foo' tried to inherit from itself

Attempting to inherit from yourself generates a warning.

    use Foo;

    use parent 'Foo';

=back

=head1 HISTORY

This module was forked from L<base> to remove the cruft

that had accumulated in it.

=head1 CAVEATS

=head1 SEE ALSO

L<base>

=head1 AUTHORS AND CONTRIBUTORS

Rafa?l Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern

=head1 MAINTAINER

Max Maischein C< corion@cpan.org >

Copyright (c) 2007 Max Maischein C<< <corion@cpan.org> >>

Based on the idea of C<base.pm>, which was introduced with Perl 5.004_04.

=head1 LICENSE

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

=cut