1 package Moose::Exporter;
7 $VERSION = eval $VERSION;
8 our $AUTHORITY = 'cpan:STEVAN';
11 use List::MoreUtils qw( uniq );
12 use Moose::Util::MetaRole;
13 use Sub::Exporter 0.980;
14 use Sub::Name qw(subname);
18 sub setup_import_methods {
19 my ( $class, %args ) = @_;
21 my $exporting_package = $args{exporting_package} ||= caller();
23 my ( $import, $unimport ) = $class->build_import_methods(%args);
26 *{ $exporting_package . '::import' } = $import;
27 *{ $exporting_package . '::unimport' } = $unimport;
30 sub build_import_methods {
31 my ( $class, %args ) = @_;
33 my $exporting_package = $args{exporting_package} ||= caller();
35 $EXPORT_SPEC{$exporting_package} = \%args;
37 my @exports_from = $class->_follow_also( $exporting_package );
39 my $export_recorder = {};
41 my ( $exports, $is_removable, $groups )
42 = $class->_make_sub_exporter_params(
43 [ @exports_from, $exporting_package ], $export_recorder );
45 my $exporter = Sub::Exporter::build_exporter(
48 groups => { default => [':all'], %$groups }
52 # $args{_export_to_main} exists for backwards compat, because
53 # Moose::Util::TypeConstraints did export to main (unlike Moose &
55 my $import = $class->_make_import_sub( $exporting_package, $exporter,
56 \@exports_from, $args{_export_to_main} );
58 my $unimport = $class->_make_unimport_sub( $exporting_package, $exports,
59 $is_removable, $export_recorder );
61 return ( $import, $unimport )
69 my $exporting_package = shift;
71 local %$seen = ( $exporting_package => 1 );
73 return uniq( _follow_also_real($exporting_package) );
76 sub _follow_also_real {
77 my $exporting_package = shift;
79 if (!exists $EXPORT_SPEC{$exporting_package}) {
80 my $loaded = Class::MOP::is_class_loaded($exporting_package);
82 die "Package in also ($exporting_package) does not seem to "
83 . "use Moose::Exporter"
84 . ($loaded ? "" : " (is it loaded?)");
87 my $also = $EXPORT_SPEC{$exporting_package}{also};
89 return unless defined $also;
91 my @also = ref $also ? @{$also} : $also;
93 for my $package (@also)
95 die "Circular reference in also parameter to Moose::Exporter between $exporting_package and $package"
98 $seen->{$package} = 1;
101 return @also, map { _follow_also_real($_) } @also;
105 sub _make_sub_exporter_params {
107 my $packages = shift;
108 my $export_recorder = shift;
114 for my $package ( @{$packages} ) {
115 my $args = $EXPORT_SPEC{$package}
116 or die "The $package package does not use Moose::Exporter\n";
118 # one group for each 'also' package
119 $groups{$package} = [
120 @{ $args->{with_caller} || [] },
121 @{ $args->{with_meta} || [] },
122 @{ $args->{as_is} || [] },
124 keys %{ $args->{groups} || {} }
127 for my $name ( @{ $args->{with_caller} } ) {
130 \&{ $package . '::' . $name };
133 my $fq_name = $package . '::' . $name;
135 $exports{$name} = $class->_make_wrapped_sub(
141 $is_removable{$name} = 1;
144 for my $name ( @{ $args->{with_meta} } ) {
147 \&{ $package . '::' . $name };
150 my $fq_name = $package . '::' . $name;
152 $exports{$name} = $class->_make_wrapped_sub_with_meta(
158 $is_removable{$name} = 1;
161 for my $name ( @{ $args->{as_is} } ) {
167 # Even though Moose re-exports things from Carp &
168 # Scalar::Util, we don't want to remove those at
169 # unimport time, because the importing package may
170 # have imported them explicitly ala
172 # use Carp qw( confess );
174 # This is a hack. Since we can't know whether they
175 # really want to keep these subs or not, we err on the
176 # safe side and leave them in.
178 ( $coderef_pkg, $name ) = Class::MOP::get_code_info($name);
180 $is_removable{$name} = $coderef_pkg eq $package ? 1 : 0;
185 \&{ $package . '::' . $name };
188 $is_removable{$name} = 1;
191 $export_recorder->{$sub} = 1;
193 $exports{$name} = sub {$sub};
196 for my $name ( keys %{ $args->{groups} } ) {
197 my $group = $args->{groups}{$name};
199 if (ref $group eq 'CODE') {
200 $groups{$name} = $class->_make_wrapped_group(
208 elsif (ref $group eq 'ARRAY') {
209 $groups{$name} = $group;
214 return ( \%exports, \%is_removable, \%groups );
219 sub _make_wrapped_sub {
223 my $export_recorder = shift;
225 # We need to set the package at import time, so that when
226 # package Foo imports has(), we capture "Foo" as the
227 # package. This lets other packages call Foo::has() and get
228 # the right package. This is done for backwards compatibility
229 # with existing production code, not because this is a good
232 my $caller = $CALLER;
234 my $wrapper = $self->_curry_wrapper($sub, $fq_name, $caller);
236 my $sub = subname($fq_name => $wrapper);
238 $export_recorder->{$sub} = 1;
244 sub _make_wrapped_sub_with_meta {
248 my $export_recorder = shift;
251 my $caller = $CALLER;
253 my $wrapper = $self->_late_curry_wrapper($sub, $fq_name,
254 sub { Class::MOP::class_of(shift) } => $caller);
256 my $sub = subname($fq_name => $wrapper);
258 $export_recorder->{$sub} = 1;
264 sub _make_wrapped_group {
266 my $package = shift; # package calling use Moose::Exporter
268 my $export_recorder = shift;
269 my $keywords = shift;
270 my $is_removable = shift;
273 my $caller = $CALLER; # package calling use PackageUsingMooseExporter -group => {args}
275 # there are plenty of ways to deal with telling the code which
276 # package it lives in. the last arg (collector hashref) is
277 # otherwise unused, so we'll stick the original package in
278 # there and act like 'with_caller' by putting the calling
279 # package name as the first arg
281 $_[3]{from} = $package;
283 my $named_code = $sub->(@_);
286 # send invalid return value error up to Sub::Exporter
287 unless (ref $named_code eq 'HASH') {
291 for my $name (keys %$named_code) {
292 my $code = $named_code->{$name};
294 my $fq_name = $package . '::' . $name;
295 my $wrapper = $class->_curry_wrapper(
301 my $sub = subname( $fq_name => $wrapper );
302 $named_code->{$name} = $sub;
304 # mark each coderef as ours
305 $keywords->{$name} = 1;
306 $is_removable->{$name} = 1;
307 $export_recorder->{$sub} = 1;
320 my $wrapper = sub { $sub->(@extra, @_) };
321 if (my $proto = prototype $sub) {
322 # XXX - Perl's prototype sucks. Use & to make set_prototype
323 # ignore the fact that we're passing "private variables"
324 &Scalar::Util::set_prototype($wrapper, $proto);
329 sub _late_curry_wrapper {
337 # resolve curried arguments at runtime via this closure
338 my @curry = ( $extra->( @ex_args ) );
339 return $sub->(@curry, @_);
342 if (my $proto = prototype $sub) {
343 # XXX - Perl's prototype sucks. Use & to make set_prototype
344 # ignore the fact that we're passing "private variables"
345 &Scalar::Util::set_prototype($wrapper, $proto);
351 my($args, %commands) = @_;
353 for (my $i = 0; $i < @{$args}; $i++) {
354 if ( my $slot_ref = $commands{$args->[$i]} ) {
355 my $arg = $args->[$i+1];
356 splice @{$args}, $i, 2;
358 if ( ref($slot_ref) eq 'ARRAY' ) {
359 @{$slot_ref} = ref($arg) eq 'ARRAY' ? @{$arg} : $arg;
369 sub _make_import_sub {
371 my $exporting_package = shift;
372 my $exporter = shift;
373 my $exports_from = shift;
374 my $export_to_main = shift;
378 # I think we could use Sub::Exporter's collector feature
379 # to do this, but that would be rather gross, since that
380 # feature isn't really designed to return a value to the
381 # caller of the exporter sub.
383 # Also, this makes sure we preserve backwards compat for
384 # _get_caller, so it always sees the arguments in the
392 -metaclass => \$metaclass,
394 -extends => \@superclasses,
397 $metaclass = Moose::Util::resolve_metaclass_alias(
398 'Class' => $metaclass
399 ) if defined $metaclass && length $metaclass;
401 # Normally we could look at $_[0], but in some weird cases
402 # (involving goto &Moose::import), $_[0] ends as something
403 # else (like Squirrel).
404 my $class = $exporting_package;
407 $CALLER = _get_caller(@_);
409 # this works because both pragmas set $^H (see perldoc
410 # perlvar) which affects the current compilation -
411 # i.e. the file who use'd us - which is why we don't need
412 # to do anything special to make it affect that file
413 # rather than this one (which is already compiled)
418 # we should never export to main
419 if ( $CALLER eq 'main' && !$export_to_main ) {
421 qq{$class does not export its sugar to the 'main' package.\n};
426 for my $c ( grep { $_->can('init_meta') } $class, @{$exports_from} ) {
427 # init_meta() can load classes using Moose or Moose::Role,
428 # which uses Moose::Exporter, which in turn sets $CALLER, so we need
429 # to protect against that.
430 local $CALLER = $CALLER;
431 $c->init_meta( for_class => $CALLER, metaclass => $metaclass );
435 if ( @superclasses ) {
436 if ( $did_init_meta ) {
437 # superclasses() can load classes using Moose or Moose::Role,
438 # which uses Moose::Exporter, which in turn sets $CALLER, so we need
439 # to protect against that.
440 local $CALLER = $CALLER;
441 $CALLER->meta->superclasses(@superclasses);
446 "Cannot provide -extends when $class does not have an init_meta() method"
452 if ( $did_init_meta ) {
453 # _apply_meta_traits() can load classes using Moose or Moose::Role,
454 # which uses Moose::Exporter, which in turn sets $CALLER, so we need
455 # to protect against that.
456 local $CALLER = $CALLER;
457 _apply_meta_traits( $CALLER, \@traits );
462 "Cannot provide traits when $class does not have an init_meta() method"
471 sub _apply_meta_traits {
472 my ( $class, $traits ) = @_;
474 return unless @{$traits};
476 my $meta = Class::MOP::class_of($class);
478 my $type = ( split /::/, ref $meta )[-1]
479 or Moose->throw_error(
480 'Cannot determine metaclass type for trait application . Meta isa '
485 ref $_ ? $_ : Moose::Util::resolve_metatrait_alias( $type => $_ )
489 return unless @resolved_traits;
491 Moose::Util::MetaRole::apply_metaclass_roles(
493 metaclass_roles => \@resolved_traits,
498 # 1 extra level because it's called by import so there's a layer
503 ( ref $_[1] && defined $_[1]->{into} ) ? $_[1]->{into}
504 : ( ref $_[1] && defined $_[1]->{into_level} )
505 ? caller( $offset + $_[1]->{into_level} )
509 sub _make_unimport_sub {
511 my $exporting_package = shift;
513 my $is_removable = shift;
514 my $export_recorder = shift;
517 my $caller = scalar caller();
518 Moose::Exporter->_remove_keywords(
520 [ keys %{$exports} ],
527 sub _remove_keywords {
530 my $keywords = shift;
531 my $is_removable = shift;
532 my $recorded_exports = shift;
536 foreach my $name ( @{ $keywords } ) {
537 next unless $is_removable->{$name};
539 if ( defined &{ $package . '::' . $name } ) {
540 my $sub = \&{ $package . '::' . $name };
542 # make sure it is from us
543 next unless $recorded_exports->{$sub};
545 # and if it is from us, then undef the slot
546 delete ${ $package . '::' }{$name};
562 Moose::Exporter - make an import() and unimport() just like Moose.pm
566 package MyApp::Moose;
571 Moose::Exporter->setup_import_methods(
572 with_caller => [ 'has_rw', 'sugar2' ],
573 as_is => [ 'sugar3', \&Some::Random::thing ],
578 my ($caller, $name, %options) = @_;
579 Class::MOP::class_of($caller)->add_attribute($name,
598 This module encapsulates the exporting of sugar functions in a
599 C<Moose.pm>-like manner. It does this by building custom C<import> and
600 C<unimport> methods for your module, based on a spec you provide.
602 It also lets you "stack" Moose-alike modules so you can export
603 Moose's sugar as well as your own, along with sugar from any random
604 C<MooseX> module, as long as they all use C<Moose::Exporter>.
606 To simplify writing exporter modules, C<Moose::Exporter> also imports
607 C<strict> and C<warnings> into your exporter module, as well as into
612 This module provides two public methods:
616 =item B<< Moose::Exporter->setup_import_methods(...) >>
618 When you call this method, C<Moose::Exporter> build custom C<import>
619 and C<unimport> methods for your module. The import method will export
620 the functions you specify, and you can also tell it to export
621 functions exported by some other module (like C<Moose.pm>).
623 The C<unimport> method cleans the callers namespace of all the
626 This method accepts the following parameters:
630 =item * with_caller => [ ... ]
632 This a list of function I<names only> to be exported wrapped and then
633 exported. The wrapper will pass the name of the calling package as the
634 first argument to the function. Many sugar functions need to know
635 their caller so they can get the calling package's metaclass object.
637 =item * as_is => [ ... ]
639 This a list of function names or sub references to be exported
640 as-is. You can identify a subroutine by reference, which is handy to
641 re-export some other module's functions directly by reference
642 (C<\&Some::Package::function>).
644 If you do export some other packages function, this function will
645 never be removed by the C<unimport> method. The reason for this is we
646 cannot know if the caller I<also> explicitly imported the sub
647 themselves, and therefore wants to keep it.
649 =item * also => $name or \@names
651 This is a list of modules which contain functions that the caller
652 wants to export. These modules must also use C<Moose::Exporter>. The
653 most common use case will be to export the functions from C<Moose.pm>.
654 Functions specified by C<with_caller> or C<as_is> take precedence over
655 functions exported by modules specified by C<also>, so that a module
656 can selectively override functions exported by another module.
658 C<Moose::Exporter> also makes sure all these functions get removed
659 when C<unimport> is called.
663 =item B<< Moose::Exporter->build_import_methods(...) >>
665 Returns two code refs, one for import and one for unimport.
667 Used by C<setup_import_methods>.
671 =head1 IMPORTING AND init_meta
673 If you want to set an alternative base object class or metaclass
674 class, simply define an C<init_meta> method in your class. The
675 C<import> method that C<Moose::Exporter> generates for you will call
676 this method (if it exists). It will always pass the caller to this
677 method via the C<for_class> parameter.
679 Most of the time, your C<init_meta> method will probably just call C<<
680 Moose->init_meta >> to do the real work:
683 shift; # our class name
684 return Moose->init_meta( @_, metaclass => 'My::Metaclass' );
687 =head1 METACLASS TRAITS
689 The C<import> method generated by C<Moose::Exporter> will allow the
690 user of your module to specify metaclass traits in a C<-traits>
691 parameter passed as part of the import:
693 use Moose -traits => 'My::Meta::Trait';
695 use Moose -traits => [ 'My::Meta::Trait', 'My::Other::Trait' ];
697 These traits will be applied to the caller's metaclass
698 instance. Providing traits for an exporting class that does not create
699 a metaclass for the caller is an error.
703 Dave Rolsky E<lt>autarch@urth.orgE<gt>
705 This is largely a reworking of code in Moose.pm originally written by
706 Stevan Little and others.
708 =head1 COPYRIGHT AND LICENSE
710 Copyright 2009 by Infinity Interactive, Inc.
712 L<http://www.iinteractive.com>
714 This library is free software; you can redistribute it and/or modify
715 it under the same terms as Perl itself.