Moose::Cookbook::Legacy::Debugging_BaseClassReplacement(User Contributed Perl DocumentatMoose::Cookbook::Legacy::Debugging_BaseClassReplacement(3)

NAME

       Moose::Cookbook::Legacy::Debugging_BaseClassReplacement - Providing an alternate base object class

VERSION

       version 2.0604

SYNOPSIS

	 package MyApp::Base;
	 use Moose;

	 extends 'Moose::Object';

	 before 'new' => sub { warn "Making a new " . $_[0] };

	 no Moose;

	 package MyApp::UseMyBase;
	 use Moose ();
	 use Moose::Exporter;

	 Moose::Exporter->setup_import_methods( also => 'Moose' );

	 sub init_meta {
	     shift;
	     return Moose->init_meta( @_, base_class => 'MyApp::Base' );
	 }

DESCRIPTION

       WARNING: Replacing the base class entirely, as opposed to applying roles to the base class, is strongly discouraged. This recipe is
       provided solely for reference when encountering older code that does this.

       A common extension is to provide an alternate base class. One way to do that is to make a "MyApp::Base" and add "extends 'MyApp::Base'" to
       every class in your application. That's pretty tedious. Instead, you can create a Moose-alike module that sets the base object class to
       "MyApp::Base" for you.

       Then, instead of writing "use Moose" you can write "use MyApp::UseMyBase".

       In this particular example, our base class issues some debugging output every time a new object is created, but you can think of some more
       interesting things to do with your own base class.

       This uses the magic of Moose::Exporter. When we call "Moose::Exporter->setup_import_methods( also => 'Moose' )" it builds "import" and
       "unimport" methods for you. The "also => 'Moose'" bit says that we want to export everything that Moose does.

       The "import" method that gets created will call our "init_meta" method, passing it "for_caller => $caller" as its arguments. The $caller is
       set to the class that actually imported us in the first place.

       See the Moose::Exporter docs for more details on its API.

NAME

       Moose::Cookbook::Extending::Recipe3 - Providing an alternate base object class

VERSION

       version 2.0402

USING MyApp::UseMyBase
       To actually use our new base class, we simply use "MyApp::UseMyBase" instead of "Moose". We get all the Moose sugar plus our new base
       class.

	 package Foo;

	 use MyApp::UseMyBase;

	 has 'size' => ( is => 'rw' );

	 no MyApp::UseMyBase;

CONCLUSION

       This is an awful lot of magic for a simple base class. You will often want to combine a metaclass trait with a base class extension, and
       that's when this technique is useful.

AUTHOR

       Moose is maintained by the Moose Cabal, along with the help of many contributors. See "CABAL" in Moose and "CONTRIBUTORS" in Moose for
       details.

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 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.

AUTHOR

       Moose is maintained by the Moose Cabal, along with the help of many contributors. See "CABAL" in Moose and "CONTRIBUTORS" in Moose for
       details.

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 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.

perl v5.16.2							    2012-09-19		Moose::Cookbook::Legacy::Debugging_BaseClassReplacement(3)