X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit%2FImport-Into.git;a=blobdiff_plain;f=lib%2FImport%2FInto.pm;h=4ef0ab77d9f1f7fed109ee0cb44ce561e8747203;hp=a8a3ada25667ef32de9490f2a23c7ad4bdfe1301;hb=19471f0fe702c9d8fdfcab8717432419598be8ec;hpb=2afb5246467e98519cbc8df4025dd6e4a929a85d diff --git a/lib/Import/Into.pm b/lib/Import/Into.pm index a8a3ada..4ef0ab7 100644 --- a/lib/Import/Into.pm +++ b/lib/Import/Into.pm @@ -3,7 +3,7 @@ package Import::Into; use strict; use warnings FATAL => 'all'; -our $VERSION = '1.0'; +our $VERSION = '1.000001'; # 1.0.1 my %importers; @@ -27,6 +27,8 @@ Import::Into - import packages into other packages package My::MultiExporter; + use Import::Into; + use Thing1 (); use Thing2 (); @@ -36,10 +38,65 @@ Import::Into - import packages into other packages Thing2->import::into($target, qw(import arguments)); } +=head1 DESCRIPTION + +Writing exporters is a pain. Some use L, some use L, +some use L, some use L ... and some things +are pragmas. + +If you want to re-export other things, you have to know which is which. +L subclasses provide export_to_level, but if they overrode their +import method all bets are off. L provides an into parameter +but figuring out something used it isn't trivial. Pragmas need to have +their C method called directly since they affect the current unit of +compilation. + +It's ... annoying. + +However, there is an approach that actually works for all of these types. + + eval "package $target; use $thing;" + +will work for anything checking caller, which is everything except pragmas. +But it doesn't work for pragmas - pragmas need: + + $thing->import; + +So, the solution is: + + my $sub = eval "package $target; sub { shift->import(\@_) }"; + $sub->($thing, @import_args); + +which means that import is called from the right place for pragmas to take +effect, and from the right package for caller checking to work. + +Remembering all this, however, is excessively irritating. So I wrote a module +so I didn't have to anymore. Loading L will create a method +C which you can call on a package to import it into another +package. So now you can simply write: + + use Import::Into; + + $thing->import::into($target, @import_args); + +Just make sure you already loaded C<$thing> - if you're receiving this from +a parameter, I recommend using L: + + use Import::Into; + use Module::Runtime qw(use_module); + + use_module($thing)->import::into($target, @import_args); + +And that's it. + =head1 AUTHOR mst - Matt S. Trout (cpan:MSTROUT) +=head1 CONTRIBUTORS + +None yet - maybe this software is perfect! (ahahahahahahahahaha) + =head1 COPYRIGHT Copyright (c) 2010-2011 the Import::Into L and L