NAME Exporter::Simple - Easier set-up of module exports SYNOPSIS package MyExport; use Exporter::Simple; my @bar : Exportable(vars) = (2, 3, 5, 7); my $foo : Exported(vars) = 42; my %baz : Exported = (a => 65, b => 66); sub hello : Exported(greet,uk) { "hello there" } sub askme : Exportable { "what you will" } sub hi : Exportable(greet,us) { "hi there" } # meanwhile, in a module far, far away use MyExport qw(:greet); print hello(); $baz{c} = 67; DESCRIPTION This module, when used by a package, allows that package to define exports in a more concise way than using `Exporter'. Instead of having to worry what goes in `@EXPORT', `@EXPORT_OK' and `%EXPORT_TAGS', you can use two attributes to define exporter behavior. This has two advantages: It frees you from the implementation details of `Exporter', and it keeps the export definitions where they belong, with the subroutines and variables. The attributes provided by this module are: `Exported' Indicates that the associated subroutine or lexical variable should be automatically exported. It will also go into the `:all' tag (per the rules of `%EXPORT_TAGS'), as well as any tags you specify as options of this attribute. For example, the following declaration sub hello : Exported(greet,uk) { ... } will cause `hello()' to be exported, but also be available in the tags `:all', `:greet' and `:uk'. `Exportable' Is like `Exported', except that the associated subroutine or lexical variable won't be automatically exported. It will still go to the `:all' tag in any case and all other tags specified as attribute options. Exporting Lexical Variables `Exporter::Simple' allows you to export lexical variables; something `Exporter' can't do. What happens is that the lexical is aliased to a global of the same name, which is then exported. So when you manipulate that global, you're really manipulating the lexical. The syntax for exporting lexical variables is the same as for subroutines as lexicals can take attributes just as subroutines do. `Exporter::Simple' expects some cooperation from you when exporting lexicals. For reasons best explained by reading the (commented) source, you need to make sure to have 1; as the last line of code in your module. This is the true value you have to return from the module anyway. Exporting Global Variables Global variables can't take attributes as of Perl 5.6.0, so it's necessary to export globals manually. This needs to happen during `BEGIN()' though, so you need to write code like this: BEGIN { export([ qw/EXPORTED_CONST @array $friend/ ], 'globals'); exportable('EXPORTABLE_CONST', 'globals'); } Urgh. However, globals will be able to take attributes in Perl 5.8.0, and this module will then be updated to reflect those capabilities. The two subroutines used to export globals are: `export($symbols, $tags)' As shown in the example above, both arguments can be either strings (to indicate one symbol or tag) or array references to indicate multiple symbols or tags. The semantics are the same as for the `Export' attribute above. `exportable($symbols, $tags)' As `export()', but does not automatically export the symbols. The semantics are the same as for the `Exportable' attribute above. These two subroutines are automatically exported by `Exporter::Simple'. The reason for this brute-force export is that these subroutines need to be used during BEGIN, but `Exporter::Simple' doesn't have a chance to use `Exporter' to export those two subroutines yet. Sigh. TODO reflection Retrieve information about exports test using two exporting modules To see whether `Exporter::Simple' is ok with more than one module using it. (I don't know why it shouldn't be, but that's what testing is for). BUGS If you find any bugs or oddities, please do inform the author. AUTHOR Marcel Grunauer, CONTRIBUTORS Damian Conway COPYRIGHT Copyright 2001 Marcel Grunauer. All rights reserved. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. SEE ALSO perl(1), Attribute::Handlers(3pm), Exporter(3pm).