MixinFactory(3pm)					User Contributed Perl Documentation					 MixinFactory(3pm)

NAME

       Class::MixinFactory - Class Factory with Selection of Mixins

SYNOPSIS

	 package MyClass;
	 use Class::MixinFactory -hasafactory;
	 sub new { ... }
	 sub foo { return "Foo Bar" }

	 package MyClass::Logging;
	 sub foo { warn "Calling foo"; (shift)->NEXT('foo', @_) }

	 package MyClass::UpperCase;
	 sub foo { uc( (shift)->NEXT('foo', @_) ) }

	 package main;

	 my $class = MyClass->class( 'Logging', 'UpperCase' );
	 print $class->new()->foo();
	 # Calls MyClass::Logging::foo, MyClass::UpperCase::foo, MyClass::foo

DESCRIPTION

       This distribution facilitates the run-time generation of classes which inherit from a base class and some optional selection of mixin
       classes.

       A factory is provided to generate the mixed classes with multiple inheritance.  A NEXT method allows method redispatch up the inheritance
       chain.

USAGE

       The Class::MixinFactory package is just a facade that loads the necessary classes and provides a few import options for compile-time
       convenience.

   Factory Interface
       To generate an object with some combination of mixins, you first pass the names of the mixin classes to a class factory which will generate
       a mixed class. (Or return the name of the already generated class, if there has been a previous request with the same combination of
       mixins.)

       You can add a factory method to your base class, create a separate factory object, or inherit to produce a factory class.

       Factory Method
	   To add a factory method to a base class, inherit from the Class::MixinFactory::HasAFactory class, or use the "-hasafactory" import
	   option:

	     package MyClass;
	     use Class::MixinFactory -hasafactory;

	     package main;
	     my $class = MyClass->class( 'Logging', 'UpperCase' );
	     print $class->new()->foo();

       Factory Class
	   To create a new class which will act as a factory for another base class, inherit from the Class::MixinFactory::Factory class, or use
	   the "-isafactory" import option:

	     package MyClass::Factory;
	     use Class::MixinFactory -isafactory;
	     MyClass::Factory->base_class( "MyClass" );

	     package main;
	     my $class = MyClass::Factory->class( 'Logging', 'UpperCase' );
	     print $class->new()->foo();

       Factory Object
	   To create an object which will act as a factory, create a Class::MixinFactory::Factory instance by calling the new() method:

	     use Class::MixinFactory;
	     my $factory = Class::MixinFactory->new();
	     $factory->base_class( "MyClass" );

	     my $class = $factory->class( 'Logging', 'UpperCase' );
	     print $class->new()->foo();

   Inheriting from a Mixed Class
       Inheriting with a Factory Method or Factory Object
	   A subclass can inherit from a mixed class:

	     package MyClass::CustomWidget;
	     @ISA = MyClass->class( 'Logging', 'UpperCase' );
	     sub foo { local $_ = (shift)->NEXT('foo', @_); tr[a-z][z-a]; $_ }

	     package main;
	     print MyClass::CustomWidget->new()->foo();

       Inheriting with a Factory Class
	   A subclass can use a factory class to define its own inheritance:

	     package MyClass::CustomWidget;
	     use Class::MixinFactory -isasubclass,
		   MyClass::Factory => 'Logging', 'UpperCase';
	     sub foo { local $_ = (shift)->NEXT('foo', @_); tr[a-z][z-a]; $_ }

	     package main;
	     print MyClass::CustomWidget->new()->foo();

   Configuring a Factory
       Factories support methods that control which classes they will use.

       The base class will be inherited from by all mixed classes.

	 $factory->base_class( "HelloWorld" );

       The mixin prefix is prepended to the mixin names passed to the class() method. Mixin names that contain a "::" are assumed to be fully
       qualified and are not changed. If empty, the base_class is used.

	 $factory->mixin_prefix( 'HelloFeature' );

       The mixed prefix is at the start of all generated class names. If empty, the base_class is used, or the factory's class name.

	 $factory->mixed_prefix( 'HelloClass' );

   Writing a Mixin Class
       Writing a mixin class is almost the same as writing a subclass, except where methods need to redispatch to the base-class implementation.
       (The SUPER::method syntax will only search for classes that the mixin itself inherits from; to search back up the inheritance tree and
       explore other branches, another redispatch mechanism is needed.)

       A method named NEXT is provided to continue the search through to the next class which provides a given method. The order in which mixins
       are stacked is significant, so the caller should understand how their behaviors interact. (See Class::MixinFactory::NEXT.)

SEE ALSO

       For distribution, installation, support, copyright and license information, see Class::MixinFactory::ReadMe.

perl v5.10.1							    2009-12-10							 MixinFactory(3pm)