use warnings;
use Class::MOP;
-use List::MoreUtils qw( uniq );
+use List::MoreUtils qw( first_index uniq );
+use Moose::Util::MetaRole;
use Sub::Exporter;
my %EXPORT_SPEC;
+sub setup_import_methods {
+ my ( $class, %args ) = @_;
+
+ my $exporting_package = $args{exporting_package} ||= caller();
+
+ my ( $import, $unimport ) = $class->build_import_methods(%args);
+
+ no strict 'refs';
+ *{ $exporting_package . '::import' } = $import;
+ *{ $exporting_package . '::unimport' } = $unimport;
+}
+
sub build_import_methods {
- my $class = shift;
- my %args = @_;
+ my ( $class, %args ) = @_;
- my $exporting_package = caller();
+ my $exporting_package = $args{exporting_package} ||= caller();
$EXPORT_SPEC{$exporting_package} = \%args;
my @exports_from = $class->_follow_also( $exporting_package );
- my $exports
- = $class->_process_exports( $exporting_package, @exports_from );
+ my $export_recorder = {};
+
+ my ( $exports, $is_removable )
+ = $class->_make_sub_exporter_params(
+ [ $exporting_package, @exports_from ], $export_recorder );
my $exporter = Sub::Exporter::build_exporter(
{
}
);
- my $import = $class->_make_import_sub( $exporter, \@exports_from );
+ # $args{_export_to_main} exists for backwards compat, because
+ # Moose::Util::TypeConstraints did export to main (unlike Moose &
+ # Moose::Role).
+ my $import = $class->_make_import_sub( $exporting_package, $exporter,
+ \@exports_from, $args{_export_to_main} );
- my $unimport = $class->_make_unimport_sub( \@exports_from, [ keys %{$exports} ] );
+ my $unimport = $class->_make_unimport_sub( $exporting_package, $exports,
+ $is_removable, $export_recorder );
- no strict 'refs';
- *{ $exporting_package . '::import' } = $import;
- *{ $exporting_package . '::unimport' } = $unimport;
+ return ( $import, $unimport )
}
{
- my %seen;
+ my $seen = {};
sub _follow_also {
my $class = shift;
my $exporting_package = shift;
- %seen = ( $exporting_package => 1 );
+ local %$seen = ( $exporting_package => 1 );
return uniq( _follow_also_real($exporting_package) );
}
sub _follow_also_real {
my $exporting_package = shift;
- die "Package in also ($exporting_package) does not seem to use MooseX::Exporter"
+ die "Package in also ($exporting_package) does not seem to use Moose::Exporter"
unless exists $EXPORT_SPEC{$exporting_package};
my $also = $EXPORT_SPEC{$exporting_package}{also};
for my $package (@also)
{
- die "Circular reference in also parameter to MooseX::Exporter between $exporting_package and $package"
- if $seen{$package};
+ die "Circular reference in also parameter to Moose::Exporter between $exporting_package and $package"
+ if $seen->{$package};
- $seen{$package} = 1;
+ $seen->{$package} = 1;
}
return @also, map { _follow_also_real($_) } @also;
}
}
-sub _process_exports {
- my $class = shift;
- my @packages = @_;
+sub _make_sub_exporter_params {
+ my $class = shift;
+ my $packages = shift;
+ my $export_recorder = shift;
my %exports;
+ my %is_removable;
- for my $package (@packages) {
+ for my $package ( @{$packages} ) {
my $args = $EXPORT_SPEC{$package}
or die "The $package package does not use Moose::Exporter\n";
\&{ $package . '::' . $name };
};
+ my $fq_name = $package . '::' . $name;
+
$exports{$name} = $class->_make_wrapped_sub(
- $package,
- $name,
- $sub
+ $fq_name,
+ $sub,
+ $export_recorder,
);
+
+ $is_removable{$name} = 1;
}
for my $name ( @{ $args->{as_is} } ) {
if ( ref $name ) {
$sub = $name;
- $name = ( Class::MOP::get_code_info($name) )[1];
+
+ # Even though Moose re-exports things from Carp &
+ # Scalar::Util, we don't want to remove those at
+ # unimport time, because the importing package may
+ # have imported them explicitly ala
+ #
+ # use Carp qw( confess );
+ #
+ # This is a hack. Since we can't know whether they
+ # really want to keep these subs or not, we err on the
+ # safe side and leave them in.
+ my $coderef_pkg;
+ ( $coderef_pkg, $name ) = Class::MOP::get_code_info($name);
+
+ $is_removable{$name} = $coderef_pkg eq $package ? 1 : 0;
}
else {
$sub = do {
no strict 'refs';
\&{ $package . '::' . $name };
};
+
+ $is_removable{$name} = 1;
}
+ $export_recorder->{$sub} = 1;
+
$exports{$name} = sub {$sub};
}
}
- return \%exports;
+ return ( \%exports, \%is_removable );
}
-{
- # This variable gets closed over in each export _generator_. Then
- # in the generator we grab the value and close over it _again_ in
- # the real export, so it gets captured each time the generator
- # runs.
- #
- # In the meantime, we arrange for the import method we generate to
- # set this variable to the caller each time it is called.
- #
- # This is all a bit confusing, but it works.
- my $CALLER;
-
- sub _make_wrapped_sub {
- my $class = shift;
- my $exporting_package = shift;
- my $name = shift;
- my $sub = shift;
-
- # We need to set the package at import time, so that when
- # package Foo imports has(), we capture "Foo" as the
- # package. This lets other packages call Foo::has() and get
- # the right package. This is done for backwards compatibility
- # with existing production code, not because this is a good
- # idea ;)
- return sub {
- my $caller = $CALLER;
- Class::MOP::subname( $exporting_package . '::'
- . $name => sub { $sub->( $caller, @_ ) } );
- };
- }
+our $CALLER;
- sub _make_import_sub {
- shift;
- my $exporter = shift;
- my $exports_from = shift;
+sub _make_wrapped_sub {
+ shift;
+ my $fq_name = shift;
+ my $sub = shift;
+ my $export_recorder = shift;
+
+ # We need to set the package at import time, so that when
+ # package Foo imports has(), we capture "Foo" as the
+ # package. This lets other packages call Foo::has() and get
+ # the right package. This is done for backwards compatibility
+ # with existing production code, not because this is a good
+ # idea ;)
+ return sub {
+ my $caller = $CALLER;
- return sub {
+ my $sub
+ = Class::MOP::subname( $fq_name => sub { $sub->( $caller, @_ ) } );
- # It's important to leave @_ as-is for the benefit of
- # Sub::Exporter.
- my $class = $_[0];
+ $export_recorder->{$sub} = 1;
- $CALLER = Moose::Exporter::_get_caller(@_);
+ return $sub;
+ };
+}
- # this works because both pragmas set $^H (see perldoc
- # perlvar) which affects the current compilation -
- # i.e. the file who use'd us - which is why we don't need
- # to do anything special to make it affect that file
- # rather than this one (which is already compiled)
+sub _make_import_sub {
+ shift;
+ my $exporting_package = shift;
+ my $exporter = shift;
+ my $exports_from = shift;
+ my $export_to_main = shift;
- strict->import;
- warnings->import;
+ return sub {
- # we should never export to main
- if ( $CALLER eq 'main' ) {
- warn
- qq{$class does not export its sugar to the 'main' package.\n};
- return;
- }
+ # I think we could use Sub::Exporter's collector feature
+ # to do this, but that would be rather gross, since that
+ # feature isn't really designed to return a value to the
+ # caller of the exporter sub.
+ #
+ # Also, this makes sure we preserve backwards compat for
+ # _get_caller, so it always sees the arguments in the
+ # expected order.
+ my $traits;
+ ( $traits, @_ ) = _strip_traits(@_);
+
+ # Normally we could look at $_[0], but in some weird cases
+ # (involving goto &Moose::import), $_[0] ends as something
+ # else (like Squirrel).
+ my $class = $exporting_package;
+
+ $CALLER = _get_caller(@_);
+
+ # this works because both pragmas set $^H (see perldoc
+ # perlvar) which affects the current compilation -
+ # i.e. the file who use'd us - which is why we don't need
+ # to do anything special to make it affect that file
+ # rather than this one (which is already compiled)
+
+ strict->import;
+ warnings->import;
+
+ # we should never export to main
+ if ( $CALLER eq 'main' && !$export_to_main ) {
+ warn
+ qq{$class does not export its sugar to the 'main' package.\n};
+ return;
+ }
- for my $c (grep { $_->can('init_meta') } $class, @{$exports_from} ) {
+ my $did_init_meta;
+ for my $c ( grep { $_->can('init_meta') } $class, @{$exports_from} ) {
+ $c->init_meta( for_class => $CALLER );
+ $did_init_meta = 1;
+ }
- $c->init_meta( for_class => $CALLER );
- }
+ if ( $did_init_meta && @{$traits} ) {
+ # The traits will use Moose::Role, which in turn uses
+ # Moose::Exporter, which in turn sets $CALLER, so we need
+ # to protect against that.
+ local $CALLER = $CALLER;
+ _apply_meta_traits( $CALLER, $traits );
+ }
+ elsif ( @{$traits} ) {
+ Moose->throw_error(
+ "Cannot provide traits when $class does not have an init_meta() method"
+ );
+ }
- goto $exporter;
- };
- }
+ goto $exporter;
+ };
+}
+
+
+sub _strip_traits {
+ my $idx = first_index { $_ eq '-traits' } @_;
+
+ return ( [], @_ ) unless $idx >= 0 && $#_ >= $idx + 1;
+
+ my $traits = $_[ $idx + 1 ];
+
+ splice @_, $idx, 2;
+
+ $traits = [ $traits ] unless ref $traits;
+
+ return ( $traits, @_ );
+}
+
+sub _apply_meta_traits {
+ my ( $class, $traits ) = @_;
+
+ return unless @{$traits};
+
+ my $meta = $class->meta();
+
+ my $type = ( split /::/, ref $meta )[-1]
+ or Moose->throw_error(
+ 'Cannot determine metaclass type for trait application . Meta isa '
+ . ref $meta );
+
+ my @resolved_traits
+ = map { Moose::Util::resolve_metatrait_alias( $type => $_ ) }
+ @$traits;
+
+ return unless @resolved_traits;
+
+ Moose::Util::MetaRole::apply_metaclass_roles(
+ for_class => $class,
+ metaclass_roles => \@resolved_traits,
+ );
}
sub _get_caller {
sub _make_unimport_sub {
shift;
- my $sources = shift;
- my $keywords = shift;
+ my $exporting_package = shift;
+ my $exports = shift;
+ my $is_removable = shift;
+ my $export_recorder = shift;
return sub {
- my $class = shift;
my $caller = scalar caller();
Moose::Exporter->_remove_keywords(
$caller,
- [ $class, @{$sources} ],
- $keywords
+ [ keys %{$exports} ],
+ $is_removable,
+ $export_recorder,
);
};
}
sub _remove_keywords {
shift;
- my $package = shift;
- my $sources = shift;
- my $keywords = shift;
-
- my %sources = map { $_ => 1 } @{$sources};
+ my $package = shift;
+ my $keywords = shift;
+ my $is_removable = shift;
+ my $recorded_exports = shift;
no strict 'refs';
- # loop through the keywords ...
- foreach my $name ( @{$keywords} ) {
+ foreach my $name ( @{ $keywords } ) {
+ next unless $is_removable->{$name};
- # if we find one ...
if ( defined &{ $package . '::' . $name } ) {
- my $keyword = \&{ $package . '::' . $name };
+ my $sub = \&{ $package . '::' . $name };
# make sure it is from us
- my ($pkg_name) = Class::MOP::get_code_info($keyword);
- next unless $sources{$pkg_name};
+ next unless $recorded_exports->{$sub};
# and if it is from us, then undef the slot
delete ${ $package . '::' }{$name};
use Moose ();
use Moose::Exporter;
- Moose::Exporter->build_export_methods(
- export => [ 'sugar1', 'sugar2', \&Some::Random::thing ],
- init_meta_args => { metaclass_class => 'MyApp::Meta::Class' ],
+ Moose::Exporter->setup_import_methods(
+ with_caller => [ 'has_rw', 'sugar2' ],
+ as_is => [ 'sugar3', \&Some::Random::thing ],
+ also => 'Moose',
);
+ sub has_rw {
+ my ($caller, $name, %options) = @_;
+ Class::MOP::Class->initialize($caller)->add_attribute($name,
+ is => 'rw',
+ %options,
+ );
+ }
+
# then later ...
package MyApp::User;
use MyApp::Moose;
has 'name';
- sugar1 'do your thing';
+ has_rw 'size';
thing;
no MyApp::Moose;
=head1 METHODS
-This module provides exactly one public method:
+This module provides two public methods:
-=head2 Moose::Exporter->build_import_methods(...)
+=head2 Moose::Exporter->setup_import_methods(...)
When you call this method, C<Moose::Exporter> build custom C<import>
and C<unimport> methods for your module. The import method will export
re-export some other module's functions directly by reference
(C<\&Some::Package::function>).
-=item * init_meta_args
+If you do export some other packages function, this function will
+never be removed by the C<unimport> method. The reason for this is we
+cannot know if the caller I<also> explicitly imported the sub
+themselves, and therefore wants to keep it.
+
+=item * also => $name or \@names
-...
+This is a list of modules which contain functions that the caller
+wants to export. These modules must also use C<Moose::Exporter>. The
+most common use case will be to export the functions from C<Moose.pm>.
+
+C<Moose::Exporter> also makes sure all these functions get removed
+when C<unimport> is called.
=back
+=head2 Moose::Exporter->build_import_methods(...)
+
+Returns two code refs, one for import and one for unimport.
+
+Used by C<setup_import_methods>.
+
+=head1 IMPORTING AND init_meta
+
+If you want to set an alternative base object class or metaclass
+class, simply define an C<init_meta> method in your class. The
+C<import> method that C<Moose::Exporter> generates for you will call
+this method (if it exists). It will always pass the caller to this
+method via the C<for_class> parameter.
+
+Most of the time, your C<init_meta> method will probably just call C<<
+Moose->init_meta >> to do the real work:
+
+ sub init_meta {
+ shift; # our class name
+ return Moose->init_meta( @_, metaclass => 'My::Metaclass' );
+ }
+
+=head1 METACLASS TRAITS
+
+The C<import> method generated by C<Moose::Exporter> will allow the
+user of your module to specify metaclass traits in a C<-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.
+
=head1 AUTHOR
Dave Rolsky E<lt>autarch@urth.orgE<gt>