# MooseX::Role::Parameterized - phpMan

## NAME
    [MooseX::Role::Parameterized] - Moose roles with composition parameters

## VERSION
    version 1.11

## SYNOPSIS
        package Counter;
        use [MooseX::Role::Parameterized];

        parameter name => (
            isa      => 'Str',
            required => 1,
        );

        role {
            my $p = shift;

            my $name = $p->name;

            has $name => (
                is      => 'rw',
                isa     => 'Int',
                default => 0,
            );

            method "increment_$name" => sub {
                my $self = shift;
                $self->$name($self->$name + 1);
            };

            method "reset_$name" => sub {
                my $self = shift;
                $self->$[name(0)];
            };
        };

        package [MyGame::Weapon];
        use Moose;

        with Counter => { name => 'enchantment' };

        package [MyGame::Wand];
        use Moose;

        with Counter => { name => 'zapped' };

## DESCRIPTION
    Your parameterized role consists of two new things: parameter
    declarations and a "role" block.

    Parameters are declared using the "parameter" keyword which very much
    resembles "has" in Moose. You can use any option that "has" in Moose
    accepts. The default value for the "is" option is "ro" as that's a very
    common case. Use "is => 'bare'" if you want no accessor. These
    parameters will get their values when the consuming class (or role) uses
    "with" in Moose. A parameter object will be constructed with these
    values, and passed to the "role" block.

    The "role" block then uses the usual [Moose::Role] keywords to build up a
    role. You can shift off the parameter object to inspect what the
    consuming class provided as parameters. You use the parameters to
    customize your role however you wish.

    There are many possible implementations for parameterized roles
    (hopefully with a consistent enough API); I believe this to be the
    easiest and most flexible design. Coincidentally, Pugs originally had an
    eerily similar design.

    See [MooseX::Role::Parameterized::Extending] for some tips on how to
    extend this module.

  Why a parameters object?
    I've been asked several times "Why use a parameter *object* and not just
    a parameter *hashref*? That would eliminate the need to explicitly
    declare your parameters."

    The benefits of using an object are similar to the benefits of using
    Moose. You get an easy way to specify lazy defaults, type constraint,
    delegation, and so on. You get to use MooseX modules.

[MooseX::Role::Parameterized::Tutorial]
    Stop! If you're new here, please read
    [MooseX::Role::Parameterized::Tutorial] for a much gentler introduction.

    You also get the usual introspective and intercessory abilities that
    come standard with the metaobject protocol. Ambitious users should be
    able to add traits to the parameters metaclass to further customize
    behavior. Please let me know if you're doing anything viciously
    complicated with this extension. :)

## CAVEATS
    You must use this syntax to declare methods in the role block: "method
    NAME => sub { ... };". This is due to a limitation in Perl. In return
    though you can use parameters *in your methods*!

## SEE ALSO
    <<http://sartak.org/2009/01/parametric-roles-in-perl-5.html>>

    <<http://sartak.org/2009/05/the-design-of-parameterized-roles.html>>

    <<http://stevan-little.blogspot.com/2009/07/thoughts-on-parameterized-rol>
    es.html>

    <<http://perldition.org/articles/Parameterized%20Roles%20with%[20MooseX::D]>
    eclare.pod>

    <<http://www.modernperlbooks.com/mt/2011/01/the-parametric-role-of-my-mvc>
    -plugin-system.html>

    <<http://jjnapiorkowski.typepad.com/modern-perl/2010/08/parameterized-rol>
    es-and-method-traits-redo.html>

    <<http://sartak.org/talks/yapc-asia-2009/>(parameterized)-roles/>

    <<https://github.com/SamuraiJack/JooseX-Role-Parameterized>> - this
    extension ported to JavaScript's Joose

## SUPPORT
    Bugs may be submitted through the RT bug tracker
    <<https://rt.cpan.org/Public/Dist/Display.html?Name=MooseX-Role-Parameter>
    ized> (or <bug-MooseX-Role-Parameterized@rt.cpan.org>
    <mailto:<bug-MooseX-Role-Parameterized@rt.cpan.org>>).

    There is also a mailing list available for users of this distribution,
    at <<http://lists.perl.org/list/moose.html>>.

    There is also an irc channel available for users of this distribution,
    at "#moose" on "irc.perl.org" <irc://irc.perl.org/#moose>.

## AUTHOR
    Shawn M Moore <<code@sartak.org>>

## CONTRIBUTORS
    *   Karen Etheridge <<ether@cpan.org>>

    *   Dave Rolsky <<autarch@urth.org>>

    *   Jesse Luehrs <<doy@tozt.net>>

    *   Oliver Charles <<oliver.g.charles@googlemail.com>>

    *   Yuval Kogman <<nothingmuch@woobling.org>>

    *   Robert 'phaylon' Sedlacek <<rs@474.at>>

    *   Florian Ragwitz <<rafl@debian.org>>

    *   Mark Fowler <<mark@twoshortplanks.com>>

    *   Chris Weyl <<cweyl@alumni.drew.edu>>

    *   Csson <<erik.carlsson@live.com>>

    *   Andy Jack <<github@veracity.ca>>

    *   Ricardo Signes <<rjbs@cpan.org>>

    *   Todd Hepler <<thepler@employees.org>>

## COPYRIGHT AND LICENSE
    This software is copyright (c) 2008 by Shawn M Moore.

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