kivitendo/modules/fallback/parent.pm @ b256bef1
| e1d4b571 | Moritz Bunkus | package parent;
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use strict;
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use vars qw($VERSION);
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$VERSION = '0.221';
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sub import {
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my $class = shift;
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my $inheritor = caller(0);
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if ( @_ and $_[0] eq '-norequire' ) {
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shift @_;
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} else {
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for ( my @filename = @_ ) {
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if ( $_ eq $inheritor ) {
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warn "Class '$inheritor' tried to inherit from itself\n";
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};
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s{::|'}{/}g;
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require "$_.pm"; # dies if the file is not found
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}
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}
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{
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no strict 'refs';
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# This is more efficient than push for the new MRO
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# at least until the new MRO is fixed
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@{"$inheritor\::ISA"} = (@{"$inheritor\::ISA"} , @_);
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};
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};
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"All your base are belong to us"
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__END__
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=head1 NAME
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parent - Establish an ISA relationship with base classes at compile time
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=head1 SYNOPSIS
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package Baz;
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use parent qw(Foo Bar);
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=head1 DESCRIPTION
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Allows you to both load one or more modules, while setting up inheritance from
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those modules at the same time. Mostly similar in effect to
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package Baz;
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BEGIN {
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require Foo;
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require Bar;
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push @ISA, qw(Foo Bar);
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}
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By default, every base class needs to live in a file of its own.
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If you want to have a subclass and its parent class in the same file, you
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can tell C<parent> not to load any modules by using the C<-norequire> switch:
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package Foo;
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sub exclaim { "I CAN HAS PERL" }
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package DoesNotLoadFooBar;
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use parent -norequire, 'Foo', 'Bar';
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# will not go looking for Foo.pm or Bar.pm
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This is equivalent to the following code:
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package Foo;
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sub exclaim { "I CAN HAS PERL" }
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package DoesNotLoadFooBar;
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push @DoesNotLoadFooBar::ISA, 'Foo';
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This is also helpful for the case where a package lives within
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a differently named file:
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package MyHash;
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use Tie::Hash;
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use parent -norequire, 'Tie::StdHash';
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This is equivalent to the following code:
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package MyHash;
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require Tie::Hash;
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push @ISA, 'Tie::StdHash';
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If you want to load a subclass from a file that C<require> would
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not consider an eligible filename (that is, it does not end in
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either C<.pm> or C<.pmc>), use the following code:
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package MySecondPlugin;
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require './plugins/custom.plugin'; # contains Plugin::Custom
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use parent -norequire, 'Plugin::Custom';
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=head1 DIAGNOSTICS
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=over 4
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=item Class 'Foo' tried to inherit from itself
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Attempting to inherit from yourself generates a warning.
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use Foo;
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use parent 'Foo';
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=back
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=head1 HISTORY
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This module was forked from L<base> to remove the cruft
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that had accumulated in it.
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=head1 CAVEATS
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=head1 SEE ALSO
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L<base>
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=head1 AUTHORS AND CONTRIBUTORS
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Rafa?l Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern
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=head1 MAINTAINER
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Max Maischein C< corion@cpan.org >
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Copyright (c) 2007 Max Maischein C<< <corion@cpan.org> >>
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Based on the idea of C<base.pm>, which was introduced with Perl 5.004_04.
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=head1 LICENSE
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This module is released under the same terms as Perl itself.
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=cut
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