NAME

Moose::Cookbook - How to cook a Moose

VERSION

version 2.2012

DESCRIPTION

The Moose cookbook is a series of recipes showing various Moose features. Most recipes present some code demonstrating some feature, and then explain the details of the code.

You should probably read the Moose::Manual first. The manual explains Moose concepts without being too code-heavy.

RECIPES

Basic Moose

These recipes will give you a good overview of Moose's capabilities, starting with simple attribute declaration, and moving on to more powerful features like laziness, types, type coercion, method modifiers, and more.

Moose::Cookbook::Basics::Point_AttributesAndSubclassing

A simple Moose-based class. Demonstrates basic Moose attributes and subclassing.

Moose::Cookbook::Basics::BankAccount_MethodModifiersAndSubclassing

A slightly more complex Moose class. Demonstrates using a method modifier in a subclass.

Moose::Cookbook::Basics::BinaryTree_AttributeFeatures

Demonstrates several attribute features, including types, weak references, predicates ("does this object have a foo?"), defaults, laziness, and triggers.

Moose::Cookbook::Basics::Company_Subtypes

Introduces the creation and use of custom types, a BUILD method, and the use of override in a subclass. This recipe also shows how to model a set of classes that could be used to model companies, people, employees, etc.

Moose::Cookbook::Basics::HTTP_SubtypesAndCoercion

This recipe covers more subtype creation, including the use of type coercions.

Moose::Cookbook::Basics::Immutable

Making a class immutable greatly increases the speed of accessors and object construction.

Moose::Cookbook::Basics::BinaryTree_BuilderAndLazyBuild - Builder methods and lazy_build

The builder feature provides an inheritable and role-composable way to provide a default attribute value.

Moose::Cookbook::Basics::Genome_OverloadingSubtypesAndCoercion

Demonstrates using operator overloading, coercion, and subtypes to model how eye color is determined during reproduction.

Moose::Cookbook::Basics::Person_BUILDARGSAndBUILD

This recipe demonstrates the use of BUILDARGS and BUILD to hook into object construction.

Moose::Cookbook::Basics::DateTime_ExtendingNonMooseParent

In this recipe, we make a Moose-based subclass of DateTime, a module which does not use Moose itself.

Moose::Cookbook::Basics::Document_AugmentAndInner

Demonstrates the use of augment method modifiers, a way of turning the usual method overriding style "inside-out".

Moose Roles

These recipes will show you how to use Moose roles.

Moose::Cookbook::Roles::Comparable_CodeReuse

Demonstrates roles, which are also sometimes known as traits or mix-ins. Roles provide a method of code re-use which is orthogonal to subclassing.

Moose::Cookbook::Roles::Restartable_AdvancedComposition

Sometimes you just want to include part of a role in your class. Sometimes you want the whole role but one of its methods conflicts with one in your class. With method exclusion and aliasing, you can work around these problems.

Moose::Cookbook::Roles::ApplicationToInstance

In this recipe, we apply a role to an existing object instance.

Meta Moose

These recipes show you how to write your own meta classes, which lets you extend the object system provided by Moose.

Moose::Cookbook::Meta::WhyMeta

If you're wondering what all this "meta" stuff is, and why you should care about it, read this "recipe".

Moose::Cookbook::Meta::Labeled_AttributeTrait

Extending Moose's attribute metaclass is a great way to add functionality. However, attributes can only have one metaclass. Applying roles to the attribute metaclass lets you provide composable attribute functionality.

Moose::Cookbook::Meta::Table_MetaclassTrait

This recipe takes the class metaclass we saw in the previous recipe and reimplements it as a metaclass trait.

Moose::Cookbook::Meta::PrivateOrPublic_MethodMetaclass

This recipe shows a custom method metaclass that implements making a method private.

Moose::Cookbook::Meta::GlobRef_InstanceMetaclass

This recipe shows an example of how you create your own meta-instance class. The meta-instance determines the internal structure of object instances and provide access to attribute slots.

In this particular instance, we use a blessed glob reference as the instance instead of a blessed hash reference.

Hooking into immutabilization (TODO)

Moose has a feature known as "immutabilization". By calling __PACKAGE__->meta()->make_immutable() after defining your class (attributes, roles, etc), you tell Moose to optimize things like object creation, attribute access, and so on.

If you are creating your own metaclasses, you may need to hook into the immutabilization system. This cuts across a number of spots, including the metaclass class, meta method classes, and possibly the meta-instance class as well.

This recipe shows you how to write extensions which immutabilize properly.

Extending Moose

These recipes cover some more ways to extend Moose, and will be useful if you plan to write your own MooseX module.

Moose::Cookbook::Extending::ExtensionOverview

There are quite a few ways to extend Moose. This recipe provides an overview of each method, and provides recommendations for when each is appropriate.

Moose::Cookbook::Extending::Debugging_BaseClassRole

Many base object class extensions can be implemented as roles. This example shows how to provide a base object class debugging role that is applied to any class that uses a notional MooseX::Debugging module.

Moose::Cookbook::Extending::Mooseish_MooseSugar

This recipe shows how to provide a replacement for Moose.pm. You may want to do this as part of the API for a MooseX module, especially if you want to default to a new metaclass class or base object class.

SNACKS

Moose::Cookbook::Snack::Keywords
Moose::Cookbook::Snack::Types

Legacy Recipes

These cover topics that are no longer considered best practice. We've kept them in case in you encounter these usages in the wild.

Moose::Cookbook::Legacy::Labeled_AttributeMetaclass
Moose::Cookbook::Legacy::Table_ClassMetaclass
Moose::Cookbook::Legacy::Debugging_BaseClassReplacement

SEE ALSO

http://www.gsph.com/index.php?Lang=En&ID=291

AUTHORS

  • Stevan Little <stevan.little@iinteractive.com>

  • Dave Rolsky <autarch@urth.org>

  • Jesse Luehrs <doy@tozt.net>

  • Shawn M Moore <code@sartak.org>

  • יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>

  • Karen Etheridge <ether@cpan.org>

  • Florian Ragwitz <rafl@debian.org>

  • Hans Dieter Pearcey <hdp@weftsoar.net>

  • Chris Prather <chris@prather.org>

  • Matt S Trout <mst@shadowcat.co.uk>

COPYRIGHT AND LICENSE

This software is copyright (c) 2006 by Infinity Interactive, Inc.

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