1 package Moose::Exporter;
7 our $XS_VERSION = $VERSION;
8 $VERSION = eval $VERSION;
9 our $AUTHORITY = 'cpan:STEVAN';
12 use List::MoreUtils qw( first_index uniq );
13 use Moose::Deprecated;
14 use Moose::Util::MetaRole;
15 use Sub::Exporter 0.980;
16 use Sub::Name qw(subname);
20 XSLoader::load( 'Moose', $XS_VERSION );
24 sub setup_import_methods {
25 my ( $class, %args ) = @_;
27 my $exporting_package = $args{exporting_package} ||= caller();
29 $class->build_import_methods(
31 install => [qw(import unimport init_meta)]
35 sub build_import_methods {
36 my ( $class, %args ) = @_;
38 my $exporting_package = $args{exporting_package} ||= caller();
40 $EXPORT_SPEC{$exporting_package} = \%args;
42 my @exports_from = $class->_follow_also($exporting_package);
44 my $export_recorder = {};
47 my $exports = $class->_make_sub_exporter_params(
48 [ @exports_from, $exporting_package ],
53 my $exporter = Sub::Exporter::build_exporter(
56 groups => { default => [':all'] }
61 $methods{import} = $class->_make_import_sub(
68 $methods{unimport} = $class->_make_unimport_sub(
75 $methods{init_meta} = $class->_make_init_meta(
80 my $package = Class::MOP::Package->initialize($exporting_package);
81 for my $to_install ( @{ $args{install} || [] } ) {
82 my $symbol = '&' . $to_install;
84 unless $methods{$to_install}
85 && !$package->has_package_symbol($symbol);
86 $package->add_package_symbol( $symbol, $methods{$to_install} );
89 return ( $methods{import}, $methods{unimport}, $methods{init_meta} );
97 my $exporting_package = shift;
99 local %$seen = ( $exporting_package => 1 );
101 return uniq( _follow_also_real($exporting_package) );
104 sub _follow_also_real {
105 my $exporting_package = shift;
107 if ( !exists $EXPORT_SPEC{$exporting_package} ) {
108 my $loaded = Class::MOP::is_class_loaded($exporting_package);
110 die "Package in also ($exporting_package) does not seem to "
111 . "use Moose::Exporter"
112 . ( $loaded ? "" : " (is it loaded?)" );
115 my $also = $EXPORT_SPEC{$exporting_package}{also};
117 return unless defined $also;
119 my @also = ref $also ? @{$also} : $also;
121 for my $package (@also) {
123 "Circular reference in 'also' parameter to Moose::Exporter between $exporting_package and $package"
124 if $seen->{$package};
126 $seen->{$package} = 1;
129 return @also, map { _follow_also_real($_) } @also;
133 sub _make_sub_exporter_params {
135 my $packages = shift;
136 my $export_recorder = shift;
137 my $is_reexport = shift;
141 for my $package ( @{$packages} ) {
142 my $args = $EXPORT_SPEC{$package}
143 or die "The $package package does not use Moose::Exporter\n";
145 for my $name ( @{ $args->{with_meta} } ) {
146 my $sub = $class->_sub_from_package( $package, $name )
149 my $fq_name = $package . '::' . $name;
151 $exports{$name} = $class->_make_wrapped_sub_with_meta(
158 for my $name ( @{ $args->{with_caller} } ) {
159 my $sub = $class->_sub_from_package( $package, $name )
162 my $fq_name = $package . '::' . $name;
164 $exports{$name} = $class->_make_wrapped_sub(
171 for my $name ( @{ $args->{as_is} } ) {
172 my ( $sub, $coderef_name );
178 ( $coderef_pkg, $coderef_name )
179 = Class::MOP::get_code_info($name);
181 if ( $coderef_pkg ne $package ) {
182 $is_reexport->{$coderef_name} = 1;
186 $sub = $class->_sub_from_package( $package, $name )
189 $coderef_name = $name;
192 $export_recorder->{$sub} = 1;
194 $exports{$coderef_name} = sub {$sub};
201 sub _sub_from_package {
208 \&{ $package . '::' . $name };
211 return $sub if defined &$sub;
213 Carp::cluck "Trying to export undefined sub ${package}::${name}";
220 sub _make_wrapped_sub {
224 my $export_recorder = shift;
226 # We need to set the package at import time, so that when
227 # package Foo imports has(), we capture "Foo" as the
228 # package. This lets other packages call Foo::has() and get
229 # the right package. This is done for backwards compatibility
230 # with existing production code, not because this is a good
233 my $caller = $CALLER;
235 my $wrapper = $self->_curry_wrapper( $sub, $fq_name, $caller );
237 my $sub = subname( $fq_name => $wrapper );
239 $export_recorder->{$sub} = 1;
245 sub _make_wrapped_sub_with_meta {
249 my $export_recorder = shift;
252 my $caller = $CALLER;
254 my $wrapper = $self->_late_curry_wrapper(
256 sub { Class::MOP::class_of(shift) } => $caller
259 my $sub = subname( $fq_name => $wrapper );
261 $export_recorder->{$sub} = 1;
273 my $wrapper = sub { $sub->( @extra, @_ ) };
274 if ( my $proto = prototype $sub ) {
276 # XXX - Perl's prototype sucks. Use & to make set_prototype
277 # ignore the fact that we're passing "private variables"
278 &Scalar::Util::set_prototype( $wrapper, $proto );
283 sub _late_curry_wrapper {
292 # resolve curried arguments at runtime via this closure
293 my @curry = ( $extra->(@ex_args) );
294 return $sub->( @curry, @_ );
297 if ( my $proto = prototype $sub ) {
299 # XXX - Perl's prototype sucks. Use & to make set_prototype
300 # ignore the fact that we're passing "private variables"
301 &Scalar::Util::set_prototype( $wrapper, $proto );
306 sub _make_import_sub {
308 my $exporting_package = shift;
309 my $exporter = shift;
310 my $exports_from = shift;
311 my $is_reexport = shift;
315 # I think we could use Sub::Exporter's collector feature
316 # to do this, but that would be rather gross, since that
317 # feature isn't really designed to return a value to the
318 # caller of the exporter sub.
320 # Also, this makes sure we preserve backwards compat for
321 # _get_caller, so it always sees the arguments in the
324 ( $traits, @_ ) = _strip_traits(@_);
327 ( $metaclass, @_ ) = _strip_metaclass(@_);
329 = Moose::Util::resolve_metaclass_alias( 'Class' => $metaclass )
330 if defined $metaclass && length $metaclass;
332 # Normally we could look at $_[0], but in some weird cases
333 # (involving goto &Moose::import), $_[0] ends as something
334 # else (like Squirrel).
335 my $class = $exporting_package;
337 $CALLER = _get_caller(@_);
339 # this works because both pragmas set $^H (see perldoc
340 # perlvar) which affects the current compilation -
341 # i.e. the file who use'd us - which is why we don't need
342 # to do anything special to make it affect that file
343 # rather than this one (which is already compiled)
349 for my $c ( grep { $_->can('init_meta') } $class, @{$exports_from} ) {
351 # init_meta can apply a role, which when loaded uses
352 # Moose::Exporter, which in turn sets $CALLER, so we need
353 # to protect against that.
354 local $CALLER = $CALLER;
355 $c->init_meta( for_class => $CALLER, metaclass => $metaclass );
359 if ( $did_init_meta && @{$traits} ) {
361 # The traits will use Moose::Role, which in turn uses
362 # Moose::Exporter, which in turn sets $CALLER, so we need
363 # to protect against that.
364 local $CALLER = $CALLER;
365 _apply_meta_traits( $CALLER, $traits );
367 elsif ( @{$traits} ) {
370 "Cannot provide traits when $class does not have an init_meta() method"
374 my ( undef, @args ) = @_;
375 my $extra = shift @args if ref $args[0] eq 'HASH';
378 if ( !$extra->{into} ) {
379 $extra->{into_level} ||= 0;
380 $extra->{into_level}++;
383 $class->$exporter( $extra, @args );
385 for my $name ( keys %{$is_reexport} ) {
388 _flag_as_reexport( \*{ join q{::}, $CALLER, $name } );
394 my $idx = first_index { $_ eq '-traits' } @_;
396 return ( [], @_ ) unless $idx >= 0 && $#_ >= $idx + 1;
398 my $traits = $_[ $idx + 1 ];
402 $traits = [$traits] unless ref $traits;
404 return ( $traits, @_ );
407 sub _strip_metaclass {
408 my $idx = first_index { $_ eq '-metaclass' } @_;
410 return ( undef, @_ ) unless $idx >= 0 && $#_ >= $idx + 1;
412 my $metaclass = $_[ $idx + 1 ];
416 return ( $metaclass, @_ );
419 sub _apply_meta_traits {
420 my ( $class, $traits ) = @_;
422 return unless @{$traits};
424 my $meta = Class::MOP::class_of($class);
426 my $type = ( split /::/, ref $meta )[-1]
427 or Moose->throw_error(
428 'Cannot determine metaclass type for trait application . Meta isa '
431 my @resolved_traits = map {
434 : Moose::Util::resolve_metatrait_alias( $type => $_ )
437 return unless @resolved_traits;
439 my %args = ( for => $class );
441 if ( $meta->isa('Moose::Meta::Role') ) {
442 $args{role_metaroles} = { role => \@resolved_traits };
445 $args{class_metaroles} = { class => \@resolved_traits };
448 Moose::Util::MetaRole::apply_metaroles(%args);
453 # 1 extra level because it's called by import so there's a layer
458 ( ref $_[1] && defined $_[1]->{into} ) ? $_[1]->{into}
459 : ( ref $_[1] && defined $_[1]->{into_level} )
460 ? caller( $offset + $_[1]->{into_level} )
464 sub _make_unimport_sub {
466 my $exporting_package = shift;
468 my $export_recorder = shift;
469 my $is_reexport = shift;
472 my $caller = scalar caller();
473 Moose::Exporter->_remove_keywords(
475 [ keys %{$exports} ],
482 sub _remove_keywords {
485 my $keywords = shift;
486 my $recorded_exports = shift;
487 my $is_reexport = shift;
491 foreach my $name ( @{$keywords} ) {
492 if ( defined &{ $package . '::' . $name } ) {
493 my $sub = \&{ $package . '::' . $name };
495 # make sure it is from us
496 next unless $recorded_exports->{$sub};
498 if ( $is_reexport->{$name} ) {
501 unless _export_is_flagged(
502 \*{ join q{::} => $package, $name } );
505 # and if it is from us, then undef the slot
506 delete ${ $package . '::' }{$name};
511 sub _make_init_meta {
523 wrapped_method_metaclass
530 $old_style_roles{$role} = $args->{$role}
531 if exists $args->{$role};
534 my %base_class_roles;
535 %base_class_roles = ( roles => $args->{base_class_roles} )
536 if exists $args->{base_class_roles};
538 my %new_style_roles = map { $_ => $args->{$_} }
539 grep { exists $args->{$_} } qw( class_metaroles role_metaroles );
541 return unless %new_style_roles || %old_style_roles || %base_class_roles;
547 return unless Class::MOP::class_of( $options{for_class} );
549 if ( %new_style_roles || %old_style_roles ) {
550 Moose::Util::MetaRole::apply_metaroles(
551 for => $options{for_class},
557 Moose::Util::MetaRole::apply_base_class_roles(
558 for_class => $options{for_class},
561 if Class::MOP::class_of( $options{for_class} )
562 ->isa('Moose::Meta::Class');
564 return Class::MOP::class_of( $options{for_class} );
579 Moose::Exporter - make an import() and unimport() just like Moose.pm
583 package MyApp::Moose;
588 Moose::Exporter->setup_import_methods(
589 with_meta => [ 'has_rw', 'sugar2' ],
590 as_is => [ 'sugar3', \&Some::Random::thing ],
595 my ( $meta, $name, %options ) = @_;
596 $meta->add_attribute(
616 This module encapsulates the exporting of sugar functions in a
617 C<Moose.pm>-like manner. It does this by building custom C<import>,
618 C<unimport>, and C<init_meta> methods for your module, based on a spec you
621 It also lets you "stack" Moose-alike modules so you can export Moose's sugar
622 as well as your own, along with sugar from any random C<MooseX> module, as
623 long as they all use C<Moose::Exporter>. This feature exists to let you bundle
624 a set of MooseX modules into a policy module that developers can use directly
625 instead of using Moose itself.
627 To simplify writing exporter modules, C<Moose::Exporter> also imports
628 C<strict> and C<warnings> into your exporter module, as well as into
633 This module provides two public methods:
637 =item B<< Moose::Exporter->setup_import_methods(...) >>
639 When you call this method, C<Moose::Exporter> builds custom C<import>,
640 C<unimport>, and C<init_meta> methods for your module. The C<import> method
641 will export the functions you specify, and can also re-export functions
642 exported by some other module (like C<Moose.pm>).
644 The C<unimport> method cleans the caller's namespace of all the exported
645 functions. This includes any functions you re-export from other
646 packages. However, if the consumer of your package also imports those
647 functions from the original package, they will I<not> be cleaned.
649 If you pass any parameters for L<Moose::Util::MetaRole>, this method will
650 generate an C<init_meta> for you as well (see below for details). This
651 C<init_meta> will call C<Moose::Util::MetaRole::apply_metaroles> and
652 C<Moose::Util::MetaRole::apply_base_class_roles> as needed.
654 Note that if any of these methods already exist, they will not be
655 overridden, you will have to use C<build_import_methods> to get the
656 coderef that would be installed.
658 This method accepts the following parameters:
662 =item * with_meta => [ ... ]
664 This list of function I<names only> will be wrapped and then exported. The
665 wrapper will pass the metaclass object for the caller as its first argument.
667 Many sugar functions will need to use this metaclass object to do something to
670 =item * as_is => [ ... ]
672 This list of function names or sub references will be exported as-is. You can
673 identify a subroutine by reference, which is handy to re-export some other
674 module's functions directly by reference (C<\&Some::Package::function>).
676 If you do export some other package's function, this function will never be
677 removed by the C<unimport> method. The reason for this is we cannot know if
678 the caller I<also> explicitly imported the sub themselves, and therefore wants
681 =item * also => $name or \@names
683 This is a list of modules which contain functions that the caller
684 wants to export. These modules must also use C<Moose::Exporter>. The
685 most common use case will be to export the functions from C<Moose.pm>.
686 Functions specified by C<with_meta> or C<as_is> take precedence over
687 functions exported by modules specified by C<also>, so that a module
688 can selectively override functions exported by another module.
690 C<Moose::Exporter> also makes sure all these functions get removed
691 when C<unimport> is called.
695 You can also provide parameters for C<Moose::Util::MetaRole::apply_metaroles>
696 and C<Moose::Util::MetaRole::base_class_roles>. Specifically, valid parameters
697 are "class_metaroles", "role_metaroles", and "base_class_roles".
699 =item B<< Moose::Exporter->build_import_methods(...) >>
701 Returns two or three code refs, one for C<import>, one for
702 C<unimport>, and optionally one for C<init_meta>, if the appropriate
703 options are passed in.
705 Accepts the additional C<install> option, which accepts an arrayref of method
706 names to install into your exporting package. The valid options are C<import>,
707 C<unimport>, and C<init_meta>. Calling C<setup_import_methods> is equivalent
708 to calling C<build_import_methods> with C<< install => [qw(import unimport
709 init_meta)] >> except that it doesn't also return the methods.
711 Used by C<setup_import_methods>.
715 =head1 IMPORTING AND init_meta
717 If you want to set an alternative base object class or metaclass class, see
718 above for details on how this module can call L<Moose::Util::MetaRole> for
721 If you want to do something that is not supported by this module, simply
722 define an C<init_meta> method in your class. The C<import> method that
723 C<Moose::Exporter> generates for you will call this method (if it exists). It
724 will always pass the caller to this method via the C<for_class> parameter.
726 Most of the time, your C<init_meta> method will probably just call C<<
727 Moose->init_meta >> to do the real work:
730 shift; # our class name
731 return Moose->init_meta( @_, metaclass => 'My::Metaclass' );
734 Keep in mind that C<build_import_methods> will return an C<init_meta>
735 method for you, which you can also call from within your custom
738 my ( $import, $unimport, $init_meta ) =
739 Moose::Exporter->build_import_methods( ... );
746 $class->$import(...);
751 sub unimport { goto &$unimport }
758 $class->$init_meta(...);
763 =head1 METACLASS TRAITS
765 The C<import> method generated by C<Moose::Exporter> will allow the
766 user of your module to specify metaclass traits in a C<-traits>
767 parameter passed as part of the import:
769 use Moose -traits => 'My::Meta::Trait';
771 use Moose -traits => [ 'My::Meta::Trait', 'My::Other::Trait' ];
773 These traits will be applied to the caller's metaclass
774 instance. Providing traits for an exporting class that does not create
775 a metaclass for the caller is an error.
779 See L<Moose/BUGS> for details on reporting bugs.
783 Dave Rolsky E<lt>autarch@urth.orgE<gt>
785 This is largely a reworking of code in Moose.pm originally written by
786 Stevan Little and others.
788 =head1 COPYRIGHT AND LICENSE
790 Copyright 2009 by Infinity Interactive, Inc.
792 L<http://www.iinteractive.com>
794 This library is free software; you can redistribute it and/or modify
795 it under the same terms as Perl itself.