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1 | package Moose::Exporter; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
ae18d5ec |
6 | our $VERSION = '0.61'; |
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; |
14 | |
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( |
e606ae5f |
43 | [ $exporting_package, @exports_from ], $export_recorder ); |
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 ); |
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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 $exporting_package = shift; |
78 | |
f5d03831 |
79 | die "Package in also ($exporting_package) does not seem to use Moose::Exporter" |
e606ae5f |
80 | unless exists $EXPORT_SPEC{$exporting_package}; |
81 | |
82 | my $also = $EXPORT_SPEC{$exporting_package}{also}; |
83 | |
84 | return unless defined $also; |
85 | |
86 | my @also = ref $also ? @{$also} : $also; |
87 | |
88 | for my $package (@also) |
89 | { |
f5d03831 |
90 | die "Circular reference in also parameter to Moose::Exporter between $exporting_package and $package" |
e606ae5f |
91 | if $seen->{$package}; |
92 | |
93 | $seen->{$package} = 1; |
94 | } |
95 | |
96 | return @also, map { _follow_also_real($_) } @also; |
97 | } |
98 | } |
99 | |
100 | sub _make_sub_exporter_params { |
101 | my $class = shift; |
102 | my $packages = shift; |
103 | my $export_recorder = shift; |
104 | |
105 | my %exports; |
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106 | my %is_removable; |
e606ae5f |
107 | |
108 | for my $package ( @{$packages} ) { |
109 | my $args = $EXPORT_SPEC{$package} |
110 | or die "The $package package does not use Moose::Exporter\n"; |
111 | |
112 | for my $name ( @{ $args->{with_caller} } ) { |
113 | my $sub = do { |
114 | no strict 'refs'; |
115 | \&{ $package . '::' . $name }; |
116 | }; |
117 | |
118 | my $fq_name = $package . '::' . $name; |
119 | |
120 | $exports{$name} = $class->_make_wrapped_sub( |
121 | $fq_name, |
122 | $sub, |
123 | $export_recorder, |
124 | ); |
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125 | |
126 | $is_removable{$name} = 1; |
e606ae5f |
127 | } |
128 | |
129 | for my $name ( @{ $args->{as_is} } ) { |
130 | my $sub; |
131 | |
132 | if ( ref $name ) { |
133 | $sub = $name; |
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134 | |
135 | # Even though Moose re-exports things from Carp & |
136 | # Scalar::Util, we don't want to remove those at |
137 | # unimport time, because the importing package may |
138 | # have imported them explicitly ala |
139 | # |
140 | # use Carp qw( confess ); |
141 | # |
142 | # This is a hack. Since we can't know whether they |
143 | # really want to keep these subs or not, we err on the |
144 | # safe side and leave them in. |
145 | my $coderef_pkg; |
146 | ( $coderef_pkg, $name ) = Class::MOP::get_code_info($name); |
147 | |
148 | $is_removable{$name} = $coderef_pkg eq $package ? 1 : 0; |
e606ae5f |
149 | } |
150 | else { |
151 | $sub = do { |
152 | no strict 'refs'; |
153 | \&{ $package . '::' . $name }; |
154 | }; |
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155 | |
156 | $is_removable{$name} = 1; |
e606ae5f |
157 | } |
158 | |
159 | $export_recorder->{$sub} = 1; |
160 | |
161 | $exports{$name} = sub {$sub}; |
162 | } |
163 | } |
164 | |
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165 | return ( \%exports, \%is_removable ); |
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166 | } |
167 | |
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168 | our $CALLER; |
169 | |
170 | sub _make_wrapped_sub { |
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171 | my $self = shift; |
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172 | my $fq_name = shift; |
173 | my $sub = shift; |
174 | my $export_recorder = shift; |
175 | |
176 | # We need to set the package at import time, so that when |
177 | # package Foo imports has(), we capture "Foo" as the |
178 | # package. This lets other packages call Foo::has() and get |
179 | # the right package. This is done for backwards compatibility |
180 | # with existing production code, not because this is a good |
181 | # idea ;) |
182 | return sub { |
183 | my $caller = $CALLER; |
184 | |
b4f00a34 |
185 | my $wrapper = $self->_make_wrapper($caller, $sub, $fq_name); |
186 | |
187 | my $sub = Class::MOP::subname($fq_name => $wrapper); |
96bb13ea |
188 | |
189 | $export_recorder->{$sub} = 1; |
190 | |
191 | return $sub; |
192 | }; |
193 | } |
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194 | |
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195 | sub _make_wrapper { |
196 | shift; |
197 | my $caller = shift; |
198 | my $sub = shift; |
199 | my $fq_name = shift; |
200 | |
201 | return sub { $sub->($caller, @_) }; |
202 | } |
203 | |
96bb13ea |
204 | sub _make_import_sub { |
205 | shift; |
206 | my $exporting_package = shift; |
207 | my $exporter = shift; |
208 | my $exports_from = shift; |
209 | my $export_to_main = shift; |
210 | |
211 | return sub { |
212 | |
213 | # I think we could use Sub::Exporter's collector feature |
214 | # to do this, but that would be rather gross, since that |
215 | # feature isn't really designed to return a value to the |
216 | # caller of the exporter sub. |
217 | # |
218 | # Also, this makes sure we preserve backwards compat for |
219 | # _get_caller, so it always sees the arguments in the |
220 | # expected order. |
221 | my $traits; |
222 | ( $traits, @_ ) = _strip_traits(@_); |
223 | |
224 | # Normally we could look at $_[0], but in some weird cases |
225 | # (involving goto &Moose::import), $_[0] ends as something |
226 | # else (like Squirrel). |
227 | my $class = $exporting_package; |
228 | |
229 | $CALLER = _get_caller(@_); |
230 | |
231 | # this works because both pragmas set $^H (see perldoc |
232 | # perlvar) which affects the current compilation - |
233 | # i.e. the file who use'd us - which is why we don't need |
234 | # to do anything special to make it affect that file |
235 | # rather than this one (which is already compiled) |
236 | |
237 | strict->import; |
238 | warnings->import; |
239 | |
240 | # we should never export to main |
241 | if ( $CALLER eq 'main' && !$export_to_main ) { |
242 | warn |
243 | qq{$class does not export its sugar to the 'main' package.\n}; |
244 | return; |
245 | } |
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246 | |
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247 | my $did_init_meta; |
248 | for my $c ( grep { $_->can('init_meta') } $class, @{$exports_from} ) { |
249 | $c->init_meta( for_class => $CALLER ); |
250 | $did_init_meta = 1; |
251 | } |
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252 | |
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253 | if ( $did_init_meta && @{$traits} ) { |
254 | # The traits will use Moose::Role, which in turn uses |
255 | # Moose::Exporter, which in turn sets $CALLER, so we need |
256 | # to protect against that. |
257 | local $CALLER = $CALLER; |
258 | _apply_meta_traits( $CALLER, $traits ); |
259 | } |
260 | elsif ( @{$traits} ) { |
261 | Moose->throw_error( |
262 | "Cannot provide traits when $class does not have an init_meta() method" |
263 | ); |
264 | } |
e606ae5f |
265 | |
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266 | goto $exporter; |
267 | }; |
e606ae5f |
268 | } |
269 | |
96bb13ea |
270 | |
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271 | sub _strip_traits { |
272 | my $idx = first_index { $_ eq '-traits' } @_; |
273 | |
274 | return ( [], @_ ) unless $idx >= 0 && $#_ >= $idx + 1; |
275 | |
276 | my $traits = $_[ $idx + 1 ]; |
277 | |
278 | splice @_, $idx, 2; |
279 | |
280 | $traits = [ $traits ] unless ref $traits; |
281 | |
282 | return ( $traits, @_ ); |
283 | } |
284 | |
285 | sub _apply_meta_traits { |
286 | my ( $class, $traits ) = @_; |
287 | |
288 | return unless @{$traits}; |
289 | |
290 | my $meta = $class->meta(); |
291 | |
292 | my $type = ( split /::/, ref $meta )[-1] |
c245d69b |
293 | or Moose->throw_error( |
e606ae5f |
294 | 'Cannot determine metaclass type for trait application . Meta isa ' |
4c0b3599 |
295 | . ref $meta ); |
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296 | |
297 | my @resolved_traits |
298 | = map { Moose::Util::resolve_metatrait_alias( $type => $_ ) } |
299 | @$traits; |
300 | |
301 | return unless @resolved_traits; |
302 | |
303 | Moose::Util::MetaRole::apply_metaclass_roles( |
304 | for_class => $class, |
305 | metaclass_roles => \@resolved_traits, |
306 | ); |
307 | } |
308 | |
309 | sub _get_caller { |
310 | # 1 extra level because it's called by import so there's a layer |
311 | # of indirection |
312 | my $offset = 1; |
313 | |
314 | return |
315 | ( ref $_[1] && defined $_[1]->{into} ) ? $_[1]->{into} |
316 | : ( ref $_[1] && defined $_[1]->{into_level} ) |
317 | ? caller( $offset + $_[1]->{into_level} ) |
318 | : caller($offset); |
319 | } |
320 | |
321 | sub _make_unimport_sub { |
322 | shift; |
323 | my $exporting_package = shift; |
324 | my $exports = shift; |
e05fb8ae |
325 | my $is_removable = shift; |
e606ae5f |
326 | my $export_recorder = shift; |
327 | |
328 | return sub { |
329 | my $caller = scalar caller(); |
330 | Moose::Exporter->_remove_keywords( |
331 | $caller, |
332 | [ keys %{$exports} ], |
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333 | $is_removable, |
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334 | $export_recorder, |
335 | ); |
336 | }; |
337 | } |
338 | |
339 | sub _remove_keywords { |
340 | shift; |
341 | my $package = shift; |
342 | my $keywords = shift; |
e05fb8ae |
343 | my $is_removable = shift; |
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344 | my $recorded_exports = shift; |
345 | |
346 | no strict 'refs'; |
347 | |
348 | foreach my $name ( @{ $keywords } ) { |
e05fb8ae |
349 | next unless $is_removable->{$name}; |
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350 | |
351 | if ( defined &{ $package . '::' . $name } ) { |
352 | my $sub = \&{ $package . '::' . $name }; |
353 | |
354 | # make sure it is from us |
355 | next unless $recorded_exports->{$sub}; |
356 | |
357 | # and if it is from us, then undef the slot |
358 | delete ${ $package . '::' }{$name}; |
359 | } |
360 | } |
361 | } |
362 | |
363 | 1; |
364 | |
365 | __END__ |
366 | |
367 | =head1 NAME |
368 | |
369 | Moose::Exporter - make an import() and unimport() just like Moose.pm |
370 | |
371 | =head1 SYNOPSIS |
372 | |
373 | package MyApp::Moose; |
374 | |
375 | use strict; |
376 | use warnings; |
377 | |
378 | use Moose (); |
379 | use Moose::Exporter; |
380 | |
381 | Moose::Exporter->setup_import_methods( |
82ad7804 |
382 | with_caller => [ 'has_rw', 'sugar2' ], |
e606ae5f |
383 | as_is => [ 'sugar3', \&Some::Random::thing ], |
384 | also => 'Moose', |
385 | ); |
386 | |
82ad7804 |
387 | sub has_rw { |
6daad0b9 |
388 | my ($caller, $name, %options) = @_; |
82ad7804 |
389 | Class::MOP::Class->initialize($caller)->add_attribute($name, |
390 | is => 'rw', |
391 | %options, |
392 | ); |
393 | } |
394 | |
e606ae5f |
395 | # then later ... |
396 | package MyApp::User; |
397 | |
398 | use MyApp::Moose; |
399 | |
400 | has 'name'; |
6daad0b9 |
401 | has_rw 'size'; |
e606ae5f |
402 | thing; |
403 | |
404 | no MyApp::Moose; |
405 | |
406 | =head1 DESCRIPTION |
407 | |
408 | This module encapsulates the logic to export sugar functions like |
409 | C<Moose.pm>. It does this by building custom C<import> and C<unimport> |
410 | methods for your module, based on a spec your provide. |
411 | |
412 | It also lets your "stack" Moose-alike modules so you can export |
413 | Moose's sugar as well as your own, along with sugar from any random |
414 | C<MooseX> module, as long as they all use C<Moose::Exporter>. |
415 | |
416 | =head1 METHODS |
417 | |
418 | This module provides two public methods: |
419 | |
420 | =head2 Moose::Exporter->setup_import_methods(...) |
421 | |
422 | When you call this method, C<Moose::Exporter> build custom C<import> |
423 | and C<unimport> methods for your module. The import method will export |
424 | the functions you specify, and you can also tell it to export |
425 | functions exported by some other module (like C<Moose.pm>). |
426 | |
427 | The C<unimport> method cleans the callers namespace of all the |
428 | exported functions. |
429 | |
430 | This method accepts the following parameters: |
431 | |
432 | =over 4 |
433 | |
434 | =item * with_caller => [ ... ] |
435 | |
436 | This a list of function I<names only> to be exported wrapped and then |
437 | exported. The wrapper will pass the name of the calling package as the |
438 | first argument to the function. Many sugar functions need to know |
439 | their caller so they can get the calling package's metaclass object. |
440 | |
441 | =item * as_is => [ ... ] |
442 | |
443 | This a list of function names or sub references to be exported |
444 | as-is. You can identify a subroutine by reference, which is handy to |
445 | re-export some other module's functions directly by reference |
446 | (C<\&Some::Package::function>). |
447 | |
e05fb8ae |
448 | If you do export some other packages function, this function will |
449 | never be removed by the C<unimport> method. The reason for this is we |
450 | cannot know if the caller I<also> explicitly imported the sub |
451 | themselves, and therefore wants to keep it. |
452 | |
e606ae5f |
453 | =item * also => $name or \@names |
454 | |
455 | This is a list of modules which contain functions that the caller |
456 | wants to export. These modules must also use C<Moose::Exporter>. The |
457 | most common use case will be to export the functions from C<Moose.pm>. |
458 | |
459 | C<Moose::Exporter> also makes sure all these functions get removed |
460 | when C<unimport> is called. |
461 | |
462 | =back |
463 | |
464 | =head2 Moose::Exporter->build_import_methods(...) |
465 | |
466 | Returns two code refs, one for import and one for unimport. |
467 | |
468 | Used by C<setup_import_methods>. |
469 | |
470 | =head1 IMPORTING AND init_meta |
471 | |
472 | If you want to set an alternative base object class or metaclass |
473 | class, simply define an C<init_meta> method in your class. The |
474 | C<import> method that C<Moose::Exporter> generates for you will call |
475 | this method (if it exists). It will always pass the caller to this |
476 | method via the C<for_class> parameter. |
477 | |
478 | Most of the time, your C<init_meta> method will probably just call C<< |
479 | Moose->init_meta >> to do the real work: |
480 | |
481 | sub init_meta { |
482 | shift; # our class name |
483 | return Moose->init_meta( @_, metaclass => 'My::Metaclass' ); |
484 | } |
485 | |
486 | =head1 METACLASS TRAITS |
487 | |
488 | The C<import> method generated by C<Moose::Exporter> will allow the |
489 | user of your module to specify metaclass traits in a C<-traits> |
490 | parameter passed as part of the import: |
491 | |
492 | use Moose -traits => 'My::Meta::Trait'; |
493 | |
494 | use Moose -traits => [ 'My::Meta::Trait', 'My::Other::Trait' ]; |
495 | |
496 | These traits will be applied to the caller's metaclass |
497 | instance. Providing traits for an exporting class that does not create |
498 | a metaclass for the caller is an error. |
499 | |
500 | =head1 AUTHOR |
501 | |
502 | Dave Rolsky E<lt>autarch@urth.orgE<gt> |
503 | |
504 | This is largely a reworking of code in Moose.pm originally written by |
505 | Stevan Little and others. |
506 | |
507 | =head1 COPYRIGHT AND LICENSE |
508 | |
509 | Copyright 2008 by Infinity Interactive, Inc. |
510 | |
511 | L<http://www.iinteractive.com> |
512 | |
513 | This library is free software; you can redistribute it and/or modify |
514 | it under the same terms as Perl itself. |
515 | |
516 | =cut |