Moose::Exporter(3pm) User Contributed Perl Documentation Moose::Exporter(3pm)NAMEMoose::Exporter - make an import() and unimport() just like Moose.pm
VERSION
version 2.2009
SYNOPSIS
package MyApp::Moose;
use Moose ();
use Moose::Exporter;
use Some::Random ();
Moose::Exporter->setup_import_methods(
with_meta => [ 'has_rw', 'sugar2' ],
as_is => [ 'sugar3', \&Some::Random::thing, 'Some::Random::other_thing' ],
also => 'Moose',
);
sub has_rw {
my ( $meta, $name, %options ) = @_;
$meta->add_attribute(
$name,
is => 'rw',
%options,
);
}
# then later ...
package MyApp::User;
use MyApp::Moose;
has 'name' => ( is => 'ro' );
has_rw 'size';
thing;
other_thing;
no MyApp::Moose;
DESCRIPTION
This module encapsulates the exporting of sugar functions in a
"Moose.pm"-like manner. It does this by building custom "import" and
"unimport" 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 "MooseX"
module, as long as they all use "Moose::Exporter". This feature exists
to let you bundle a set of MooseX modules into a policy module that
developers can use directly instead of using Moose itself.
To simplify writing exporter modules, "Moose::Exporter" also imports
"strict" and "warnings" into your exporter module, as well as into
modules that use it.
METHODS
This module provides two public methods:
Moose::Exporter->setup_import_methods(...)
When you call this method, "Moose::Exporter" builds custom "import" and
"unimport" methods for your module. The "import" method will export the
functions you specify, and can also re-export functions exported by
some other module (like "Moose.pm"). If you pass any parameters for
Moose::Util::MetaRole, the "import" method will also call
Moose::Util::MetaRole::apply_metaroles and
Moose::Util::MetaRole::apply_base_class_roles as needed, after making
sure the metaclass is initialized.
The "unimport" method cleans the caller's namespace of all the exported
functions. This includes any functions you re-export from other
packages. However, if the consumer of your package also imports those
functions from the original package, they will not be cleaned.
Note that if any of these methods already exist, they will not be
overridden, you will have to use "build_import_methods" to get the
coderef that would be installed.
This method accepts the following parameters:
· with_meta => [ ... ]
This list of function names only will be wrapped and then exported.
The wrapper will pass the metaclass object for the caller as its
first argument.
Many sugar functions will need to use this metaclass object to do
something to the calling package.
· as_is => [ ... ]
This list of function names or sub references will be exported as-
is. You can identify a subroutine by reference, which is handy to
re-export some other module's functions directly by reference
("\&Some::Package::function").
If you do export some other package's function, this function will
never be removed by the "unimport" method. The reason for this is
we cannot know if the caller also explicitly imported the sub
themselves, and therefore wants to keep it.
· trait_aliases => [ ... ]
This is a list of package names which should have shortened aliases
exported, similar to the functionality of aliased. Each element in
the list can be either a package name, in which case the export
will be named as the last namespace component of the package, or an
arrayref, whose first element is the package to alias to, and
second element is the alias to export.
· also => $name or \@names
This is a list of modules which contain functions that the caller
wants to export. These modules must also use "Moose::Exporter". The
most common use case will be to export the functions from
"Moose.pm". Functions specified by "with_meta" or "as_is" take
precedence over functions exported by modules specified by "also",
so that a module can selectively override functions exported by
another module.
"Moose::Exporter" also makes sure all these functions get removed
when "unimport" is called.
· meta_lookup => sub { ... }
This is a function which will be called to provide the metaclass to
be operated upon by the exporter. This is an advanced feature
intended for use by package generator modules in the vein of
MooseX::Role::Parameterized in order to simplify reusing sugar from
other modules that use "Moose::Exporter". This function is used,
for example, to select the metaclass to bind to functions that are
exported using the "with_meta" option.
This function will receive one parameter: the class name into which
the sugar is being exported. The default implementation is:
sub { Class::MOP::class_of(shift) }
Accordingly, this function is expected to return a metaclass.
You can also provide parameters for
Moose::Util::MetaRole::apply_metaroles and
Moose::Util::MetaRole::apply_base_class_roles. Specifically, valid
parameters are "class_metaroles", "role_metaroles", and
"base_class_roles".
Moose::Exporter->build_import_methods(...)
Returns three code refs, one for "import", one for "unimport" and one
for "init_meta".
Accepts the additional "install" option, which accepts an arrayref of
method names to install into your exporting package. The valid options
are "import" and "unimport". Calling "setup_import_methods" is
equivalent to calling "build_import_methods" with "install =>
[qw(import unimport)]" except that it doesn't also return the methods.
The "import" method is built using Sub::Exporter. This means that it
can take a hashref of the form "{ into => $package }" to specify the
package it operates on.
Used by "setup_import_methods".
IMPORTING AND init_meta
If you want to set an alternative base object class or metaclass class,
see above for details on how this module can call Moose::Util::MetaRole
for you.
If you want to do something that is not supported by this module,
simply define an "init_meta" method in your class. The "import" method
that "Moose::Exporter" generates for you will call this method (if it
exists). It will always pass the caller to this method via the
"for_class" parameter.
Most of the time, your "init_meta" method will probably just call
"Moose->init_meta" to do the real work:
sub init_meta {
shift; # our class name
return Moose->init_meta( @_, metaclass => 'My::Metaclass' );
}
METACLASS TRAITS
The "import" method generated by "Moose::Exporter" will allow the user
of your module to specify metaclass traits in a "-traits" parameter
passed as part of the import:
use Moose -traits => 'My::Meta::Trait';
use Moose -traits => [ 'My::Meta::Trait', 'My::Other::Trait' ];
These traits will be applied to the caller's metaclass instance.
Providing traits for an exporting class that does not create a
metaclass for the caller is an error.
BUGS
See "BUGS" in Moose for details on reporting bugs.
AUTHORS
· Stevan Little <stevan.little@iinteractive.com>
· Dave Rolsky <autarch@urth.org>
· Jesse Luehrs <doy@tozt.net>
· Shawn M Moore <code@sartak.org>
· יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
· Karen Etheridge <ether@cpan.org>
· Florian Ragwitz <rafl@debian.org>
· Hans Dieter Pearcey <hdp@weftsoar.net>
· Chris Prather <chris@prather.org>
· Matt S Trout <mst@shadowcat.co.uk>
COPYRIGHT AND LICENSE
This software is copyright (c) 2006 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 v5.26.1 2017-12-21 Moose::Exporter(3pm)
