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1 | package Moose::Exporter; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
e6ab9ca5 |
6 | our $VERSION = '0.83'; |
ae18d5ec |
7 | $VERSION = eval $VERSION; |
8 | our $AUTHORITY = 'cpan:STEVAN'; |
9 | |
e606ae5f |
10 | use Class::MOP; |
11 | use List::MoreUtils qw( first_index uniq ); |
12 | use Moose::Util::MetaRole; |
13 | use Sub::Exporter; |
9f2230e9 |
14 | use Sub::Name qw(subname); |
e606ae5f |
15 | |
16 | my %EXPORT_SPEC; |
17 | |
18 | sub setup_import_methods { |
19 | my ( $class, %args ) = @_; |
20 | |
21 | my $exporting_package = $args{exporting_package} ||= caller(); |
22 | |
23 | my ( $import, $unimport ) = $class->build_import_methods(%args); |
24 | |
25 | no strict 'refs'; |
26 | *{ $exporting_package . '::import' } = $import; |
27 | *{ $exporting_package . '::unimport' } = $unimport; |
28 | } |
29 | |
30 | sub build_import_methods { |
31 | my ( $class, %args ) = @_; |
32 | |
33 | my $exporting_package = $args{exporting_package} ||= caller(); |
34 | |
35 | $EXPORT_SPEC{$exporting_package} = \%args; |
36 | |
37 | my @exports_from = $class->_follow_also( $exporting_package ); |
38 | |
39 | my $export_recorder = {}; |
40 | |
e05fb8ae |
41 | my ( $exports, $is_removable ) |
42 | = $class->_make_sub_exporter_params( |
f44ec924 |
43 | [ @exports_from, $exporting_package ], $export_recorder ); |
e606ae5f |
44 | |
45 | my $exporter = Sub::Exporter::build_exporter( |
46 | { |
47 | exports => $exports, |
48 | groups => { default => [':all'] } |
49 | } |
50 | ); |
51 | |
52 | # $args{_export_to_main} exists for backwards compat, because |
53 | # Moose::Util::TypeConstraints did export to main (unlike Moose & |
54 | # Moose::Role). |
55 | my $import = $class->_make_import_sub( $exporting_package, $exporter, |
56 | \@exports_from, $args{_export_to_main} ); |
57 | |
58 | my $unimport = $class->_make_unimport_sub( $exporting_package, $exports, |
e05fb8ae |
59 | $is_removable, $export_recorder ); |
e606ae5f |
60 | |
61 | return ( $import, $unimport ) |
62 | } |
63 | |
64 | { |
65 | my $seen = {}; |
66 | |
67 | sub _follow_also { |
68 | my $class = shift; |
69 | my $exporting_package = shift; |
70 | |
71 | local %$seen = ( $exporting_package => 1 ); |
72 | |
73 | return uniq( _follow_also_real($exporting_package) ); |
74 | } |
75 | |
76 | sub _follow_also_real { |
77 | my $exporting_package = shift; |
78 | |
ba1a3c2f |
79 | if (!exists $EXPORT_SPEC{$exporting_package}) { |
80 | my $loaded = Class::MOP::is_class_loaded($exporting_package); |
81 | |
82 | die "Package in also ($exporting_package) does not seem to " |
83 | . "use Moose::Exporter" |
84 | . ($loaded ? "" : " (is it loaded?)"); |
85 | } |
e606ae5f |
86 | |
87 | my $also = $EXPORT_SPEC{$exporting_package}{also}; |
88 | |
89 | return unless defined $also; |
90 | |
91 | my @also = ref $also ? @{$also} : $also; |
92 | |
93 | for my $package (@also) |
94 | { |
f5d03831 |
95 | die "Circular reference in also parameter to Moose::Exporter between $exporting_package and $package" |
e606ae5f |
96 | if $seen->{$package}; |
97 | |
98 | $seen->{$package} = 1; |
99 | } |
100 | |
101 | return @also, map { _follow_also_real($_) } @also; |
102 | } |
103 | } |
104 | |
105 | sub _make_sub_exporter_params { |
106 | my $class = shift; |
107 | my $packages = shift; |
108 | my $export_recorder = shift; |
109 | |
110 | my %exports; |
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111 | my %is_removable; |
e606ae5f |
112 | |
113 | for my $package ( @{$packages} ) { |
114 | my $args = $EXPORT_SPEC{$package} |
115 | or die "The $package package does not use Moose::Exporter\n"; |
116 | |
117 | for my $name ( @{ $args->{with_caller} } ) { |
118 | my $sub = do { |
119 | no strict 'refs'; |
120 | \&{ $package . '::' . $name }; |
121 | }; |
122 | |
123 | my $fq_name = $package . '::' . $name; |
124 | |
125 | $exports{$name} = $class->_make_wrapped_sub( |
126 | $fq_name, |
127 | $sub, |
128 | $export_recorder, |
129 | ); |
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130 | |
131 | $is_removable{$name} = 1; |
e606ae5f |
132 | } |
133 | |
134 | for my $name ( @{ $args->{as_is} } ) { |
135 | my $sub; |
136 | |
137 | if ( ref $name ) { |
138 | $sub = $name; |
e05fb8ae |
139 | |
140 | # Even though Moose re-exports things from Carp & |
141 | # Scalar::Util, we don't want to remove those at |
142 | # unimport time, because the importing package may |
143 | # have imported them explicitly ala |
144 | # |
145 | # use Carp qw( confess ); |
146 | # |
147 | # This is a hack. Since we can't know whether they |
148 | # really want to keep these subs or not, we err on the |
149 | # safe side and leave them in. |
150 | my $coderef_pkg; |
151 | ( $coderef_pkg, $name ) = Class::MOP::get_code_info($name); |
152 | |
153 | $is_removable{$name} = $coderef_pkg eq $package ? 1 : 0; |
e606ae5f |
154 | } |
155 | else { |
156 | $sub = do { |
157 | no strict 'refs'; |
158 | \&{ $package . '::' . $name }; |
159 | }; |
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160 | |
161 | $is_removable{$name} = 1; |
e606ae5f |
162 | } |
163 | |
164 | $export_recorder->{$sub} = 1; |
165 | |
166 | $exports{$name} = sub {$sub}; |
167 | } |
168 | } |
169 | |
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170 | return ( \%exports, \%is_removable ); |
e606ae5f |
171 | } |
172 | |
96bb13ea |
173 | our $CALLER; |
174 | |
175 | sub _make_wrapped_sub { |
b4f00a34 |
176 | my $self = shift; |
96bb13ea |
177 | my $fq_name = shift; |
178 | my $sub = shift; |
179 | my $export_recorder = shift; |
180 | |
181 | # We need to set the package at import time, so that when |
182 | # package Foo imports has(), we capture "Foo" as the |
183 | # package. This lets other packages call Foo::has() and get |
184 | # the right package. This is done for backwards compatibility |
185 | # with existing production code, not because this is a good |
186 | # idea ;) |
187 | return sub { |
188 | my $caller = $CALLER; |
189 | |
6de00734 |
190 | my $wrapper = $self->_curry_wrapper($sub, $fq_name, $caller); |
b4f00a34 |
191 | |
9f2230e9 |
192 | my $sub = subname($fq_name => $wrapper); |
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193 | |
194 | $export_recorder->{$sub} = 1; |
195 | |
196 | return $sub; |
197 | }; |
198 | } |
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199 | |
6de00734 |
200 | sub _curry_wrapper { |
badbc528 |
201 | my $class = shift; |
b4f00a34 |
202 | my $sub = shift; |
203 | my $fq_name = shift; |
6de00734 |
204 | my @extra = @_; |
b4f00a34 |
205 | |
6de00734 |
206 | my $wrapper = sub { $sub->(@extra, @_) }; |
badbc528 |
207 | if (my $proto = prototype $sub) { |
2d7e979b |
208 | # XXX - Perl's prototype sucks. Use & to make set_prototype |
6de00734 |
209 | # ignore the fact that we're passing "private variables" |
2d7e979b |
210 | &Scalar::Util::set_prototype($wrapper, $proto); |
badbc528 |
211 | } |
212 | return $wrapper; |
b4f00a34 |
213 | } |
214 | |
96bb13ea |
215 | sub _make_import_sub { |
216 | shift; |
217 | my $exporting_package = shift; |
218 | my $exporter = shift; |
219 | my $exports_from = shift; |
220 | my $export_to_main = shift; |
221 | |
222 | return sub { |
223 | |
224 | # I think we could use Sub::Exporter's collector feature |
225 | # to do this, but that would be rather gross, since that |
226 | # feature isn't really designed to return a value to the |
227 | # caller of the exporter sub. |
228 | # |
229 | # Also, this makes sure we preserve backwards compat for |
230 | # _get_caller, so it always sees the arguments in the |
231 | # expected order. |
232 | my $traits; |
233 | ( $traits, @_ ) = _strip_traits(@_); |
234 | |
8f30b86e |
235 | my $metaclass; |
236 | ( $metaclass, @_ ) = _strip_metaclass(@_); |
237 | |
96bb13ea |
238 | # Normally we could look at $_[0], but in some weird cases |
239 | # (involving goto &Moose::import), $_[0] ends as something |
240 | # else (like Squirrel). |
241 | my $class = $exporting_package; |
242 | |
243 | $CALLER = _get_caller(@_); |
244 | |
245 | # this works because both pragmas set $^H (see perldoc |
246 | # perlvar) which affects the current compilation - |
247 | # i.e. the file who use'd us - which is why we don't need |
248 | # to do anything special to make it affect that file |
249 | # rather than this one (which is already compiled) |
250 | |
251 | strict->import; |
252 | warnings->import; |
253 | |
254 | # we should never export to main |
255 | if ( $CALLER eq 'main' && !$export_to_main ) { |
256 | warn |
257 | qq{$class does not export its sugar to the 'main' package.\n}; |
258 | return; |
259 | } |
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260 | |
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261 | my $did_init_meta; |
262 | for my $c ( grep { $_->can('init_meta') } $class, @{$exports_from} ) { |
816208bc |
263 | # init_meta can apply a role, which when loaded uses |
264 | # Moose::Exporter, which in turn sets $CALLER, so we need |
265 | # to protect against that. |
fdeb8354 |
266 | local $CALLER = $CALLER; |
89bcd625 |
267 | $c->init_meta( for_class => $CALLER, metaclass => $metaclass ); |
96bb13ea |
268 | $did_init_meta = 1; |
269 | } |
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270 | |
96bb13ea |
271 | if ( $did_init_meta && @{$traits} ) { |
272 | # The traits will use Moose::Role, which in turn uses |
273 | # Moose::Exporter, which in turn sets $CALLER, so we need |
274 | # to protect against that. |
275 | local $CALLER = $CALLER; |
276 | _apply_meta_traits( $CALLER, $traits ); |
277 | } |
278 | elsif ( @{$traits} ) { |
70ea9161 |
279 | require Moose; |
96bb13ea |
280 | Moose->throw_error( |
281 | "Cannot provide traits when $class does not have an init_meta() method" |
282 | ); |
283 | } |
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284 | |
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285 | goto $exporter; |
286 | }; |
e606ae5f |
287 | } |
288 | |
96bb13ea |
289 | |
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290 | sub _strip_traits { |
291 | my $idx = first_index { $_ eq '-traits' } @_; |
292 | |
293 | return ( [], @_ ) unless $idx >= 0 && $#_ >= $idx + 1; |
294 | |
295 | my $traits = $_[ $idx + 1 ]; |
296 | |
297 | splice @_, $idx, 2; |
298 | |
299 | $traits = [ $traits ] unless ref $traits; |
300 | |
301 | return ( $traits, @_ ); |
302 | } |
303 | |
8f30b86e |
304 | sub _strip_metaclass { |
305 | my $idx = first_index { $_ eq '-metaclass' } @_; |
306 | |
307 | return ( undef, @_ ) unless $idx >= 0 && $#_ >= $idx + 1; |
308 | |
309 | my $metaclass = $_[ $idx + 1 ]; |
310 | |
311 | splice @_, $idx, 2; |
312 | |
313 | return ( $metaclass, @_ ); |
314 | } |
315 | |
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316 | sub _apply_meta_traits { |
317 | my ( $class, $traits ) = @_; |
318 | |
319 | return unless @{$traits}; |
320 | |
2571a16d |
321 | my $meta = Class::MOP::class_of($class); |
e606ae5f |
322 | |
323 | my $type = ( split /::/, ref $meta )[-1] |
c245d69b |
324 | or Moose->throw_error( |
e606ae5f |
325 | 'Cannot determine metaclass type for trait application . Meta isa ' |
4c0b3599 |
326 | . ref $meta ); |
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327 | |
328 | my @resolved_traits |
329 | = map { Moose::Util::resolve_metatrait_alias( $type => $_ ) } |
330 | @$traits; |
331 | |
332 | return unless @resolved_traits; |
333 | |
334 | Moose::Util::MetaRole::apply_metaclass_roles( |
335 | for_class => $class, |
336 | metaclass_roles => \@resolved_traits, |
337 | ); |
338 | } |
339 | |
340 | sub _get_caller { |
341 | # 1 extra level because it's called by import so there's a layer |
342 | # of indirection |
343 | my $offset = 1; |
344 | |
345 | return |
346 | ( ref $_[1] && defined $_[1]->{into} ) ? $_[1]->{into} |
347 | : ( ref $_[1] && defined $_[1]->{into_level} ) |
348 | ? caller( $offset + $_[1]->{into_level} ) |
349 | : caller($offset); |
350 | } |
351 | |
352 | sub _make_unimport_sub { |
353 | shift; |
354 | my $exporting_package = shift; |
355 | my $exports = shift; |
e05fb8ae |
356 | my $is_removable = shift; |
e606ae5f |
357 | my $export_recorder = shift; |
358 | |
359 | return sub { |
360 | my $caller = scalar caller(); |
361 | Moose::Exporter->_remove_keywords( |
362 | $caller, |
363 | [ keys %{$exports} ], |
e05fb8ae |
364 | $is_removable, |
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365 | $export_recorder, |
366 | ); |
367 | }; |
368 | } |
369 | |
370 | sub _remove_keywords { |
371 | shift; |
372 | my $package = shift; |
373 | my $keywords = shift; |
e05fb8ae |
374 | my $is_removable = shift; |
e606ae5f |
375 | my $recorded_exports = shift; |
376 | |
377 | no strict 'refs'; |
378 | |
379 | foreach my $name ( @{ $keywords } ) { |
e05fb8ae |
380 | next unless $is_removable->{$name}; |
e606ae5f |
381 | |
382 | if ( defined &{ $package . '::' . $name } ) { |
383 | my $sub = \&{ $package . '::' . $name }; |
384 | |
385 | # make sure it is from us |
386 | next unless $recorded_exports->{$sub}; |
387 | |
388 | # and if it is from us, then undef the slot |
389 | delete ${ $package . '::' }{$name}; |
390 | } |
391 | } |
392 | } |
393 | |
e2fa092d |
394 | sub import { |
395 | strict->import; |
396 | warnings->import; |
397 | } |
398 | |
e606ae5f |
399 | 1; |
400 | |
401 | __END__ |
402 | |
403 | =head1 NAME |
404 | |
405 | Moose::Exporter - make an import() and unimport() just like Moose.pm |
406 | |
407 | =head1 SYNOPSIS |
408 | |
409 | package MyApp::Moose; |
410 | |
e606ae5f |
411 | use Moose (); |
412 | use Moose::Exporter; |
413 | |
414 | Moose::Exporter->setup_import_methods( |
82ad7804 |
415 | with_caller => [ 'has_rw', 'sugar2' ], |
e606ae5f |
416 | as_is => [ 'sugar3', \&Some::Random::thing ], |
417 | also => 'Moose', |
418 | ); |
419 | |
82ad7804 |
420 | sub has_rw { |
6daad0b9 |
421 | my ($caller, $name, %options) = @_; |
4a8a45bc |
422 | Class::MOP::class_of($caller)->add_attribute($name, |
82ad7804 |
423 | is => 'rw', |
424 | %options, |
425 | ); |
426 | } |
427 | |
e606ae5f |
428 | # then later ... |
429 | package MyApp::User; |
430 | |
431 | use MyApp::Moose; |
432 | |
433 | has 'name'; |
6daad0b9 |
434 | has_rw 'size'; |
e606ae5f |
435 | thing; |
436 | |
437 | no MyApp::Moose; |
438 | |
439 | =head1 DESCRIPTION |
440 | |
fd7ab111 |
441 | This module encapsulates the exporting of sugar functions in a |
442 | C<Moose.pm>-like manner. It does this by building custom C<import> and |
443 | C<unimport> methods for your module, based on a spec you provide. |
e606ae5f |
444 | |
24aef5e1 |
445 | It also lets you "stack" Moose-alike modules so you can export |
e606ae5f |
446 | Moose's sugar as well as your own, along with sugar from any random |
447 | C<MooseX> module, as long as they all use C<Moose::Exporter>. |
448 | |
10e0127a |
449 | To simplify writing exporter modules, C<Moose::Exporter> also imports |
450 | C<strict> and C<warnings> into your exporter module, as well as into |
451 | modules that use it. |
452 | |
e606ae5f |
453 | =head1 METHODS |
454 | |
455 | This module provides two public methods: |
456 | |
4b68e0de |
457 | =over 4 |
458 | |
459 | =item B<< Moose::Exporter->setup_import_methods(...) >> |
e606ae5f |
460 | |
461 | When you call this method, C<Moose::Exporter> build custom C<import> |
462 | and C<unimport> methods for your module. The import method will export |
463 | the functions you specify, and you can also tell it to export |
464 | functions exported by some other module (like C<Moose.pm>). |
465 | |
466 | The C<unimport> method cleans the callers namespace of all the |
467 | exported functions. |
468 | |
469 | This method accepts the following parameters: |
470 | |
4b68e0de |
471 | =over 8 |
e606ae5f |
472 | |
473 | =item * with_caller => [ ... ] |
474 | |
475 | This a list of function I<names only> to be exported wrapped and then |
476 | exported. The wrapper will pass the name of the calling package as the |
477 | first argument to the function. Many sugar functions need to know |
478 | their caller so they can get the calling package's metaclass object. |
479 | |
480 | =item * as_is => [ ... ] |
481 | |
482 | This a list of function names or sub references to be exported |
483 | as-is. You can identify a subroutine by reference, which is handy to |
484 | re-export some other module's functions directly by reference |
485 | (C<\&Some::Package::function>). |
486 | |
e05fb8ae |
487 | If you do export some other packages function, this function will |
488 | never be removed by the C<unimport> method. The reason for this is we |
489 | cannot know if the caller I<also> explicitly imported the sub |
490 | themselves, and therefore wants to keep it. |
491 | |
e606ae5f |
492 | =item * also => $name or \@names |
493 | |
494 | This is a list of modules which contain functions that the caller |
495 | wants to export. These modules must also use C<Moose::Exporter>. The |
496 | most common use case will be to export the functions from C<Moose.pm>. |
ae8817b6 |
497 | Functions specified by C<with_caller> or C<as_is> take precedence over |
498 | functions exported by modules specified by C<also>, so that a module |
499 | can selectively override functions exported by another module. |
e606ae5f |
500 | |
501 | C<Moose::Exporter> also makes sure all these functions get removed |
502 | when C<unimport> is called. |
503 | |
504 | =back |
505 | |
4b68e0de |
506 | =item B<< Moose::Exporter->build_import_methods(...) >> |
e606ae5f |
507 | |
508 | Returns two code refs, one for import and one for unimport. |
509 | |
510 | Used by C<setup_import_methods>. |
511 | |
4b68e0de |
512 | =back |
513 | |
e606ae5f |
514 | =head1 IMPORTING AND init_meta |
515 | |
516 | If you want to set an alternative base object class or metaclass |
517 | class, simply define an C<init_meta> method in your class. The |
518 | C<import> method that C<Moose::Exporter> generates for you will call |
519 | this method (if it exists). It will always pass the caller to this |
520 | method via the C<for_class> parameter. |
521 | |
522 | Most of the time, your C<init_meta> method will probably just call C<< |
523 | Moose->init_meta >> to do the real work: |
524 | |
525 | sub init_meta { |
526 | shift; # our class name |
527 | return Moose->init_meta( @_, metaclass => 'My::Metaclass' ); |
528 | } |
529 | |
530 | =head1 METACLASS TRAITS |
531 | |
532 | The C<import> method generated by C<Moose::Exporter> will allow the |
533 | user of your module to specify metaclass traits in a C<-traits> |
534 | parameter passed as part of the import: |
535 | |
536 | use Moose -traits => 'My::Meta::Trait'; |
537 | |
538 | use Moose -traits => [ 'My::Meta::Trait', 'My::Other::Trait' ]; |
539 | |
540 | These traits will be applied to the caller's metaclass |
541 | instance. Providing traits for an exporting class that does not create |
542 | a metaclass for the caller is an error. |
543 | |
544 | =head1 AUTHOR |
545 | |
546 | Dave Rolsky E<lt>autarch@urth.orgE<gt> |
547 | |
548 | This is largely a reworking of code in Moose.pm originally written by |
549 | Stevan Little and others. |
550 | |
551 | =head1 COPYRIGHT AND LICENSE |
552 | |
2840a3b2 |
553 | Copyright 2009 by Infinity Interactive, Inc. |
e606ae5f |
554 | |
555 | L<http://www.iinteractive.com> |
556 | |
557 | This library is free software; you can redistribute it and/or modify |
558 | it under the same terms as Perl itself. |
559 | |
560 | =cut |