Moose::Exporter(3) User Contributed Perl Documentation Moose::Exporter(3)NAMEMoose::Exporter - make an import() and unimport() just like Moose.pm
VERSION
version 2.1005
SYNOPSIS
package MyApp::Moose;
use Moose ();
use Moose::Exporter;
Moose::Exporter->setup_import_methods(
with_meta => [ 'has_rw', 'sugar2' ],
as_is => [ 'sugar3', \&Some::Random::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';
has_rw 'size';
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::base_class_roles". Specifically, valid
parameters are "class_metaroles", "role_metaroles", and
"base_class_roles".
Moose::Exporter->build_import_methods(...)
Returns two code refs, one for "import" and one for "unimport".
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.
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) 2013 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 v5.18.1 2013-08-07 Moose::Exporter(3)
