Moose::Cookbook - How to cook a Moose
The Moose cookbook is a series of recipes taken from the Moose test suite. Each recipe presents some code, which demonstrates some of the features of Moose, and then proceeds to explain the details of the code.
We also provide a Moose::Cookbook::FAQ and a Moose::Cookbook::WTF for common questions and problems people have with Moose.
These recipes will give you a good idea of what Moose is capable, starting with simple attribute declaration, and moving on to more powerful features like laziness, types, type coercion, method modifiers, and more.
A simple Moose-based class. Demonstrated Moose attributes and subclassing.
A slightly more complex Moose class. Demonstrates using a method modifier in a subclass.
Demonstrates several attribute features, including types, weak references, predicates ("does this object have a foo?"), defaults, and lazy attribute uction.
Introduces the creation and use of custom types, a BUILD method, and the use of override in a subclass.
BUILD
override
More type examples, including the use of type coercions.
Demonstrates the use of augment method modifiers, a way of turning the usual method overriding style "inside-out".
augment
Making a class immutable greatly increases the speed of accessors and object construction.
abstract goes here
Work off of this http://code2.0beta.co.uk/moose/svn/Moose/trunk/t/200_examples/007_Child_Parent_attr_inherit.t
The builder feature provides an inheritable and role-composable way to provide a default attribute value.
Demonstrates using operator overloading, coercion, and subtypes to model how eye color is determined during reproduction.
We need a good recipe demonstrating how these work.
These recipes will show you how to use Moose roles.
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.
Sometimes you just want to include part of a role in your class. Sometimes you want the whole role but one if its methods conflicts with one in your class. With method exclusion and aliasing, you can work around these problems.
These recipes show you how to write your own meta classes, which lets you extend the object system provide by Moose.
If you're wondering what all this "meta" stuff is, and why you should care about it, read this "recipe".
One way to extend Moose is to provide your own attribute metaclasses. Attribute metaclasses let you extend attribute declarations (with has) and behavior to provide additional attribute functionality.
has
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.
If you want to store more information about your classes, you'll have to extend Moose::Meta::Class. Doing so is simple, but you'll probably also want to provide some sugar, so see Moose::Cookbook::Extending::Recipe2 as well.
Moose::Meta::Class
This example takes the class metaclass we saw in the previous recipe and reimplements it as a metaclass trait.
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.
__PACKAGE__->meta()->make_immutable()
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.
These recipes cover some more ways to extend Moose, and will be useful if you plan to write your own MooseX module.
MooseX
There are quite a number of ways to extend Moose. This recipe explains provides an overview of each method, and provides recommendations for when each is appropriate.
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.
MooseX::Debugging
You may find that you want to provide an alternate base object class along with a meta extension, or maybe you just want to add some functionality to all your classes without typing extends 'MyApp::Base' over and over.
extends 'MyApp::Base'
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.
Moose.pm
Stevan Little <stevan@iinteractive.com>
Copyright 2006-2008 by Infinity Interactive, Inc.
http://www.iinteractive.com
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Moose, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Moose
CPAN shell
perl -MCPAN -e shell install Moose
For more information on module installation, please visit the detailed CPAN module installation guide.