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#========================================================================
#
# Badger::Mixin
#
# DESCRIPTION
#   Base class for mixins that allow you to "mix in" functionality using
#   composition rather than inheritance.  Similar in concept to roles,
#   although operating at a slightly lower level.
#
# AUTHOR
#   Andy Wardley   <abw@wardley.org>
#
#========================================================================

package Badger::Mixin;

use Badger::Class
    version   => 3.00,
    debug     => 0,
    base      => 'Badger::Exporter',
    import    => 'class',
    constants => 'PKG REFS ONCE ARRAY DELIMITER',
    words     => 'EXPORT_TAGS MIXINS';


sub mixin {
    my $self   = shift;
    my $target = shift || (caller())[0];
    my $class  = $self->class;
    my $mixins = $class->list_vars(MIXINS); 
    $self->debug("mixinto($target): ", $self->dump_data($mixins), "\n") if $DEBUG;
    $self->export($target, $mixins);
}

sub mixins {
    my $self   = shift;
    my $syms   = @_ == 1 ? shift : [ @_ ];
    my $class  = $self->class;
    my $mixins = $class->var_default(MIXINS, [ ]);
    
    $syms = [ split(DELIMITER, $syms) ] 
        unless ref $syms eq ARRAY;

    push(@$mixins, @$syms);
    $self->export_any($syms);
    
    return $mixins;
}


1;

=head1 NAME

Badger::Mixin - base class mixin object

=head1 SYNOPSIS

The C<Badger::Mixin> module is a base class for mixin modules.  
You can use the L<Badger::Class> module to declare mixins:

    package Your::Mixin::Module;
    
    use Badger::Class
        mixins => '$FOO @BAR %BAZ bam';
        
    # some sample data/methods to mixin
    our $FOO = 'Some random text';
    our @BAR = qw( foo bar baz );
    our %BAZ = ( hello => 'world' );
    sub bam { 'just testing' };

Behind the scenes this adds C<Badger::Mixin> as a base class of 
C<Your::Mixin::Module> and calls the L<mixins> method to declare
what symbols can be mixed into another module.  You can write this
code manually if you prefer:

    package Your::Mixin::Module;
    
    use base 'Badger::Mixin';
    
    __PACKAGE__->mixins('$FOO @BAR %BAZ bam');
    
    # sample data/methods as before

=head1 DESCRIPTION

The L<Badger::Mixin> module is a base class for mixin modules. Mixins are