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Moose::Cookbook::Extending::Debugging_BaseClassRole(3)	User Contributed Perl Documentation Moose::Cookbook::Extending::Debugging_BaseClassRole(3)

NAME
Moose::Cookbook::Extending::Debugging_BaseClassRole - Providing a role for the base object class VERSION
version 2.0604 SYNOPSIS
package MooseX::Debugging; use Moose::Exporter; Moose::Exporter->setup_import_methods( base_class_roles => ['MooseX::Debugging::Role::Object'], ); package MooseX::Debugging::Role::Object; use Moose::Role; sub BUILD {} after BUILD => sub { my $self = shift; warn "Made a new " . ( ref $self ) . " object "; }; DESCRIPTION
In this example, we provide a role for the base object class that adds some simple debugging output. Every time an object is created, it spits out a warning saying what type of object it was. Obviously, a real debugging role would do something more interesting, but this recipe is all about how we apply that role. In this case, with the combination of Moose::Exporter and Moose::Util::MetaRole, we ensure that when a module does "use MooseX::Debugging", it automatically gets the debugging role applied to its base object class. There are a few pieces of code worth looking at more closely. Moose::Exporter->setup_import_methods( base_class_roles => ['MooseX::Debugging::Role::Object'], ); This creates an "import" method in the "MooseX::Debugging" package. Since we are not actually exporting anything, we do not pass "setup_import_methods" any parameters related to exports, but we need to have an "import" method to ensure that our "init_meta" method is called. The "init_meta" is created by "setup_import_methods" for us, since we passed the "base_class_roles" parameter. The generated "init_meta" will in turn call Moose::Util::MetaRole::apply_base_class_roles. sub BUILD {} after BUILD => sub { ... }; Due to the way role composition currently works, if the class that a role is composed into contains a "BUILD" method, then that will override the "BUILD" method in any roles it composes, which is typically not what you want. Using a method modifier on "BUILD" avoids this issue, since method modifiers compose together rather than being overridden. Method modifiers require that a method exists in order to wrap, however, so we also provide a stub method to wrap if no "BUILD" method exists in the class. 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::Extending::Debugging_BaseClassRole(3)

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Moose::Cookbook::Extending::Mooseish_MooseSugar(3)	User Contributed Perl Documentation	Moose::Cookbook::Extending::Mooseish_MooseSugar(3)

NAME
Moose::Cookbook::Extending::Mooseish_MooseSugar - Acting like Moose.pm and providing sugar Moose-style VERSION
version 2.0604 SYNOPSIS
package MyApp::Mooseish; use Moose::Exporter; Moose::Exporter->setup_import_methods( with_meta => ['has_table'], class_metaroles => { class => ['MyApp::Meta::Class::Trait::HasTable'], }, ); sub has_table { my $meta = shift; $meta->table(shift); } package MyApp::Meta::Class::Trait::HasTable; use Moose::Role; has table => ( is => 'rw', isa => 'Str', ); DESCRIPTION
This recipe expands on the use of Moose::Exporter we saw in Moose::Cookbook::Extending::ExtensionOverview and the class metaclass trait we saw in Moose::Cookbook::Meta::Table_MetaclassTrait. In this example we provide our own metaclass trait, and we also export a "has_table" sugar function. The "with_meta" parameter specifies a list of functions that should be wrapped before exporting. The wrapper simply ensures that the importing package's appropriate metaclass object is the first argument to the function, so we can do "my $meta = shift;". See the Moose::Exporter docs for more details on its API. USING MyApp::Mooseish The purpose of all this code is to provide a Moose-like interface. Here's what it would look like in actual use: package MyApp::User; use namespace::autoclean; use Moose; use MyApp::Mooseish; has_table 'User'; has 'username' => ( is => 'ro' ); has 'password' => ( is => 'ro' ); sub login { ... } CONCLUSION
Providing sugar functions can make your extension look much more Moose-ish. See Fey::ORM for a more extensive example. 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::Extending::Mooseish_MooseSugar(3)
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