using this module is that I<it preserves any subclassing or roles
already applied to the user's metaclasses>. This means that your
extension is cooperative I<by default>, and consumers of your
-extension can easily use it with other role-based extensions.
+extension can easily use it with other role-based extensions. Most
+uses of L<Moose::Util::MetaRole> can be handled by L<Moose::Exporter>
+directly; see the L<Moose::Exporter> docs.
package MooseX::Embiggen;
use Moose ();
use Moose::Exporter;
- use Moose::Util::MetaRole;
use MooseX::Embiggen::Role::Meta::Class;
use MooseX::Embiggen::Role::Meta::Attribute;
use MooseX::Embiggen::Role::Meta::Method::Constructor;
use MooseX::Embiggen::Role::Object;
- Moose::Exporter->setup_import_methods( also => 'Moose' );
+ my ($import, $unimport, $init_meta) = Moose::Exporter->build_import_methods(
+ also => ['Moose']
+ metaclass_roles => ['MooseX::Embiggen::Role::Meta::Class'],
+ attribute_metaclass_roles => ['MooseX::Embiggen::Role::Meta::Attribute'],
+ constructor_class_roles =>
+ ['MooseX::Embiggen::Role::Meta::Method::Constructor'],
+ base_class_roles => ['MooseX::Embiggen::Role::Object'],
+ install => [qw(import unimport)],
+ );
sub init_meta {
- shift; # just your package name
+ my $package = shift;
my %options = @_;
-
Moose->init_meta(%options);
-
- my $meta = Moose::Util::MetaRole::apply_metaclass_roles(
- for_class => $options{for_class},
- metaclass_roles => ['MooseX::Embiggen::Role::Meta::Class'],
- attribute_metaclass_roles =>
- ['MooseX::Embiggen::Role::Meta::Attribute'],
- constructor_class_roles =>
- ['MooseX::Embiggen::Role::Meta::Method::Constructor'],
- );
-
- Moose::Util::MetaRole::apply_base_class_roles(
- for_class => $options{for_class},
- roles => ['MooseX::Embiggen::Role::Object'],
- );
-
- return $meta;
+ return $package->$init_meta(%options);
}
As you can see from this example, you can use L<Moose::Util::MetaRole>
also => 'Moose',
);
- sub init_meta { ... }
-
sub embiggen {
my $caller = shift;
$caller->meta()->embiggen(@_);
package MooseX::Debugging;
- use Moose ();
use Moose::Exporter;
- use Moose::Util::MetaRole;
- Moose::Exporter->setup_import_methods;
-
- sub init_meta {
- shift;
- my %options = @_;
-
- my $meta = Moose->init_meta(%options);
-
- Moose::Util::MetaRole::apply_base_class_roles(
- for_class => $options{for_class},
- roles => ['MooseX::Debugging::Role::Object'],
- );
-
- return $meta;
- }
+ Moose::Exporter->setup_import_methods(
+ base_class_roles => ['MooseX::Debugging::Role::Object'],
+ );
package MooseX::Debugging::Role::Object;
There are a few pieces of code worth looking at more closely.
- Moose::Exporter->setup_import_methods;
+ Moose::Exporter->setup_import_methods(
+ base_class_roles => ['MooseX::Debugging::Role::Object'],
+ );
This creates an C<import> method in the C<MooseX::Debugging>
package. Since we are not actually exporting anything, we do not pass
-C<setup_import_methods> any parameters. However, we need to have an
-C<import> method to ensure that our C<init_meta> method is called.
-
-Then in our C<init_meta> method we have this line:
-
- Moose->init_meta(%options);
-
-This is a bit of boilerplate that almost every extension will
-use. This ensures that the caller has a normal Moose metaclass
-I<before> we go and add traits to it.
-
-The C<< Moose->init_meta >> method does ensures that the caller has a
-sane metaclass, and we don't want to replicate that logic in our
-extension. If the C<< Moose->init_meta >> was already called (because
-the caller did C<S<use Moose>> before using our extension), then
-calling C<< Moose->init_meta >> again is effectively a no-op.
+C<setup_import_methods> any parameters related to exports, but we need
+to have an C<import> method to ensure that our C<init_meta> method is
+called. This call also automatically generates the appropriate
+C<init_meta>, which will pass the C<base_class_roles> option through
+to L<Moose::Util::MetaRole>.
=head1 AUTHOR
my $exporting_package = $args{exporting_package} ||= caller();
- my ( $import, $unimport ) = $class->build_import_methods(%args);
-
- no strict 'refs';
- *{ $exporting_package . '::import' } = $import;
- *{ $exporting_package . '::unimport' } = $unimport;
+ $class->build_import_methods(
+ %args,
+ install => [qw(import unimport init_meta)]
+ );
}
sub build_import_methods {
}
);
+ my %methods;
# $args{_export_to_main} exists for backwards compat, because
# Moose::Util::TypeConstraints did export to main (unlike Moose &
# Moose::Role).
- my $import = $class->_make_import_sub( $exporting_package, $exporter,
- \@exports_from, $args{_export_to_main} );
+ $methods{import} = $class->_make_import_sub( $exporting_package,
+ $exporter, \@exports_from, $args{_export_to_main} );
- my $unimport = $class->_make_unimport_sub( $exporting_package, $exports,
- $is_removable, $export_recorder );
+ $methods{unimport} = $class->_make_unimport_sub( $exporting_package,
+ $exports, $is_removable, $export_recorder );
+
+ $methods{init_meta} = $class->_make_init_meta( $exporting_package,
+ \%args );
+
+ my $package = Class::MOP::Package->initialize($exporting_package);
+ for my $to_install (@{ $args{install} || [] }) {
+ my $symbol = '&' . $to_install;
+ next unless $methods{$to_install}
+ && !$package->has_package_symbol($symbol);
+ $package->add_package_symbol($symbol, $methods{$to_install});
+ }
- return ( $import, $unimport )
+ return ( $methods{import}, $methods{unimport}, $methods{init_meta} )
}
{
}
}
+sub _make_init_meta {
+ shift;
+ my $class = shift;
+ my $args = shift;
+
+ my %metaclass_roles;
+ for my $role (map { "${_}_roles" }
+ qw(metaclass
+ attribute_metaclass
+ method_metaclass
+ wrapped_method_metaclass
+ instance_metaclass
+ constructor_class
+ destructor_class
+ error_class
+ application_to_class_class
+ application_to_role_class
+ application_to_instance_class)) {
+ $metaclass_roles{$role} = $args->{$role} if exists $args->{$role};
+ }
+
+ my %base_class_roles;
+ %base_class_roles = (roles => $args->{base_class_roles})
+ if exists $args->{base_class_roles};
+
+ return unless %metaclass_roles || %base_class_roles;
+
+ return sub {
+ shift;
+ my %options = @_;
+ return unless Class::MOP::class_of($options{for_class});
+ Moose::Util::MetaRole::apply_metaclass_roles(
+ for_class => $options{for_class},
+ %metaclass_roles,
+ );
+ Moose::Util::MetaRole::apply_base_class_roles(
+ for_class => $options{for_class},
+ %base_class_roles,
+ ) if Class::MOP::class_of($options{for_class})->isa('Moose::Meta::Class');
+ return Class::MOP::class_of($options{for_class});
+ };
+}
+
sub import {
strict->import;
warnings->import;
=head1 DESCRIPTION
This module encapsulates the exporting of sugar functions in a
-C<Moose.pm>-like manner. It does this by building custom C<import> and
-C<unimport> methods for your module, based on a spec you provide.
+C<Moose.pm>-like manner. It does this by building custom C<import>,
+C<unimport>, and optionally C<init_meta> methods for your module,
+based on a spec you provide.
It also lets you "stack" Moose-alike modules so you can export
Moose's sugar as well as your own, along with sugar from any random
=item B<< Moose::Exporter->setup_import_methods(...) >>
-When you call this method, C<Moose::Exporter> build custom C<import>
-and C<unimport> methods for your module. The import method will export
-the functions you specify, and you can also tell it to export
-functions exported by some other module (like C<Moose.pm>).
+When you call this method, C<Moose::Exporter> builds custom C<import>,
+C<unimport>, and C<init_meta> methods for your module. The C<import>
+method will export the functions you specify, and you can also tell it
+to export functions exported by some other module (like C<Moose.pm>).
The C<unimport> method cleans the callers namespace of all the
exported functions.
+The C<init_meta> method will be generated if any parameters for
+L<Moose::Util::MetaRole> are passed to C<setup_import_methods> (see
+below). It will handle passing along the required traits to
+C<apply_metaclass_roles> and C<apply_base_class_roles> as needed.
+
+Note that if any of these methods already exist, they will not be
+overridden, you will have to use C<build_import_methods> to get the
+coderef that would be installed.
+
This method accepts the following parameters:
=over 8
=back
+Any of the C<*_roles> options for
+C<Moose::Util::MetaRole::apply_metaclass_roles> are also valid here,
+and C<base_class_roles> will be passed along to the C<roles> parameter
+of C<Moose::Util::MetaRole::apply_base_class_roles>.
+
=item B<< Moose::Exporter->build_import_methods(...) >>
-Returns two code refs, one for import and one for unimport.
+Returns two or three code refs, one for C<import>, one for
+C<unimport>, and optionally one for C<init_meta>, if the appropriate
+options are passed in.
+
+Accepts the additional C<install> option, which accepts an arrayref of
+method names to install into your exporter (C<import>, C<unimport>,
+and C<init_meta>). Calling C<setup_import_methods> is equivalent to
+calling C<build_import_methods> with
+C<< install => [qw(import unimport init_meta)] >> (except that it
+doesn't also return the methods).
Used by C<setup_import_methods>.
=head1 IMPORTING AND init_meta
If you want to set an alternative base object class or metaclass
-class, simply define an C<init_meta> method in your class. The
-C<import> method that C<Moose::Exporter> generates for you will call
-this method (if it exists). It will always pass the caller to this
-method via the C<for_class> parameter.
+class, see above for how to pass options to L<Moose::Util::MetaRole>
+through the options to C<setup_import_methods>. If you want to do
+something not supported by this, simply define an C<init_meta> method
+in your class. The C<import> method that C<Moose::Exporter> generates
+for you will call this method (if it exists). It will always pass the
+caller to this method via the C<for_class> parameter.
Most of the time, your C<init_meta> method will probably just call C<<
Moose->init_meta >> to do the real work:
return Moose->init_meta( @_, metaclass => 'My::Metaclass' );
}
+Keep in mind that C<build_import_methods> will return an C<init_meta>
+method for you, which you can also call from within your custom
+C<init_meta>.
+
=head1 METACLASS TRAITS
The C<import> method generated by C<Moose::Exporter> will allow the
attributes defined yet.
The easiest way to ensure that this happens is to use
-L<Moose::Exporter> and provide an C<init_meta> method that will be
-called when imported.
+L<Moose::Exporter>, which can generate the appropriate C<init_meta>
+method for you, and make sure it is called when imported.
=head1 FUNCTIONS
--- /dev/null
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 13;
+use Test::Moose qw(does_ok);
+
+{
+ package Foo::Trait::Class;
+ use Moose::Role;
+}
+
+{
+ package Foo::Trait::Attribute;
+ use Moose::Role;
+}
+
+{
+ package Foo::Role::Base;
+ use Moose::Role;
+}
+
+{
+ package Foo::Exporter;
+ use Moose::Exporter;
+
+ Moose::Exporter->setup_import_methods(
+ metaclass_roles => ['Foo::Trait::Class'],
+ attribute_metaclass_roles => ['Foo::Trait::Attribute'],
+ base_class_roles => ['Foo::Role::Base'],
+ );
+}
+
+{
+ package Foo;
+ use Moose;
+ Foo::Exporter->import;
+
+ has foo => (is => 'ro');
+
+ ::does_ok(Foo->meta, 'Foo::Trait::Class');
+ ::does_ok(Foo->meta->get_attribute('foo'), 'Foo::Trait::Attribute');
+ ::does_ok('Foo', 'Foo::Role::Base');
+}
+
+{
+ package Foo::Exporter::WithMoose;
+ use Moose ();
+ use Moose::Exporter;
+
+ my ($import, $unimport, $init_meta) =
+ Moose::Exporter->build_import_methods(
+ also => 'Moose',
+ metaclass_roles => ['Foo::Trait::Class'],
+ attribute_metaclass_roles => ['Foo::Trait::Attribute'],
+ base_class_roles => ['Foo::Role::Base'],
+ install => [qw(import unimport)],
+ );
+
+ sub init_meta {
+ my $package = shift;
+ my %options = @_;
+ ::pass('custom init_meta was called');
+ Moose->init_meta(%options);
+ return $package->$init_meta(%options);
+ }
+}
+
+{
+ package Foo2;
+ Foo::Exporter::WithMoose->import;
+
+ has(foo => (is => 'ro'));
+
+ ::isa_ok('Foo2', 'Moose::Object');
+ ::isa_ok(Foo2->meta, 'Moose::Meta::Class');
+ ::does_ok(Foo2->meta, 'Foo::Trait::Class');
+ ::does_ok(Foo2->meta->get_attribute('foo'), 'Foo::Trait::Attribute');
+ ::does_ok('Foo2', 'Foo::Role::Base');
+}
+
+{
+ package Foo::Role;
+ use Moose::Role;
+ Foo::Exporter->import;
+
+ ::does_ok(Foo::Role->meta, 'Foo::Trait::Class');
+}
+
+{
+ package Foo::Exporter::WithMooseRole;
+ use Moose::Role ();
+ use Moose::Exporter;
+
+ my ($import, $unimport, $init_meta) =
+ Moose::Exporter->build_import_methods(
+ also => 'Moose::Role',
+ metaclass_roles => ['Foo::Trait::Class'],
+ attribute_metaclass_roles => ['Foo::Trait::Attribute'],
+ base_class_roles => ['Foo::Role::Base'],
+ install => [qw(import unimport)],
+ );
+
+ sub init_meta {
+ my $package = shift;
+ my %options = @_;
+ ::pass('custom init_meta was called');
+ Moose::Role->init_meta(%options);
+ return $package->$init_meta(%options);
+ }
+}
+
+{
+ package Foo2::Role;
+ Foo::Exporter::WithMooseRole->import;
+
+ ::isa_ok(Foo2::Role->meta, 'Moose::Meta::Role');
+ ::does_ok(Foo2::Role->meta, 'Foo::Trait::Class');
+}
projects / gitmo/Moose.git / commitdiff