NAME

MooseX::Types::Implements - Require objects to implement a role/interface

VERSION

version 1.103350

SYNOPSIS

    package My::Class;

    use Moose;
    use MooseX::Types::Implements qw( Implements );

    has 'vehicle' => (
        is => 'rw',
        isa => Implements[qw( My::Interfaces::Driveable )],
    );

    has 'pet_animal' => (
        is => 'rw',
        isa => Implements[qw( My::Interfaces::Pet My::Interfaces::Animal )],
    );

Interfaces definitions:

    package My::Interfaces::Driveable;
    use Moose::Role;

    requires qw( drive stop );


    package My::Interfaces::Pet;
    use Moose::Role;

    requires qw( play obey );


    package My::Interfaces::Animal;
    use Moose::Role;

    requires qw( eat sleep roam );

Classes:

    package My::Car;
    use Moose;
    with qw( My::Interfaces::Driveable );

    sub drive { ... };
    sub stop { ... };


    package My::Bicycle;
    use Moose;
    with qw( My::Interfaces::Driveable );

    sub drive { ... };
    sub stop { ... };


    package My::TimeMachine;
    use Moose;

    sub teleport { ... };


    package My::Dog;
    use Moose;
    with qw( My::Interfaces::Pet My::Interfaces::Animal );

    sub play { ... };
    sub obey { ... };

    sub eat { ... };
    sub sleep { ... };
    sub roam { ... };


    package My::Skunk;
    use Moose;
    with qw( My::Interfaces::Animal );

    sub eat { ... };
    sub sleep { ... };
    sub roam { ... };

And finally:

    package main;

    my $class = My::Class->new();

    # My::Car and My::Bicycle implement My::Interfaces::Driveable
    $class->vehicle( My::Car->new() );
    $class->vehicle( My::Bicycle->new() );

    # throws error - you cannot drive TimeMachine
    $class->vehicle( My::TimeMachine->new() );


    # dog is a Pet and an Animal
    $class->pet_animal( My::Dog->new() );

    # throws error - Skunk is an Animal, but not really a Pet
    $class->pet_animal( My::Skunk->new() );

DESCRIPTION

This class provides parameterizable polymorphic type constraint.

TYPES

Implements

    # single role
    has 'vehicle' => (
        is => 'rw',
        isa => Implements[qw( My::Interfaces::Driveable )],
    );

    # all roles need to be implemented
    has 'pet_animal' => (
        is => 'rw',
        isa => Implements[qw( My::Interfaces::Pet My::Interfaces::Animal )],
    );

Implements is a parameterizable type constraint that requires Objects to implement specified roles (automatically loaded).

Subtyping is also supported:

    package My::Types;
    use MooseX::Types::Implements qw( Implements );
    use MooseX::Types -declare => [qw(
        Driveable
    )];

    subtype Driveable,
        as Implements[qw( My::Interfaces::Driveable )],
        message {
            "Object '$_' needs to implement My::Interfaces::Driveable"
        };

    package My::Class;
    use Moose;
    use My::Types qw( Driveable );

    has 'vehicle' => (
        is => 'rw',
        isa => Driveable,
    );

SEE ALSO

• MooseX::Types::Parameterizable

• MooseX::Types

AUTHOR

Alex J. G. Burzyński <ajgb@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2010 by Alex J. G. Burzyński <ajgb@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.