30 ˆÁÀ 0¿¾0ˆl–Ðz¾”êe¶¥´ ƒq¦® Å1hßÁ „_iŸ_‹uÐb &=LV[(ÁÀ.§package Module::Pluggable; use strict; use vars qw($VERSION $FORCE_SEARCH_ALL_PATHS); use Module::Pluggable::Object; use if $] > 5.017, 'deprecate'; # ObQuote: # Bob Porter: Looks like you've been missing a lot of work lately. # Peter Gibbons: I wouldn't say I've been missing it, Bob! $VERSION = '4.8'; $FORCE_SEARCH_ALL_PATHS = 0; sub import { my $class = shift; my %opts = @_; my ($pkg, $file) = caller; # the default name for the method is 'plugins' my $sub = $opts{'sub_name'} || 'plugins'; # get our package my ($package) = $opts{'package'} || $pkg; $opts{filename} = $file; $opts{package} = $package; $opts{force_search_all_paths} = $FORCE_SEARCH_ALL_PATHS unless exists $opts{force_search_all_paths}; my $finder = Module::Pluggable::Object->new(%opts); my $subroutine = sub { my $self = shift; return $finder->plugins(@_) }; my $searchsub = sub { my $self = shift; my ($action,@paths) = @_; $finder->{'search_path'} = ["${package}::Plugin"] if ($action eq 'add' and not $finder->{'search_path'} ); push @{$finder->{'search_path'}}, @paths if ($action eq 'add'); $finder->{'search_path'} = \@paths if ($action eq 'new'); return $finder->{'search_path'}; }; my $onlysub = sub { my ($self, $only) = @_; if (defined $only) { $finder->{'only'} = $only; }; return $finder->{'only'}; }; my $exceptsub = sub { my ($self, $except) = @_; if (defined $except) { $finder->{'except'} = $except; }; return $finder->{'except'}; }; no strict 'refs'; no warnings qw(redefine prototype); *{"$package\::$sub"} = $subroutine; *{"$package\::search_path"} = $searchsub; *{"$package\::only"} = $onlysub; *{"$package\::except"} = $exceptsub; } 1; =pod =head1 NAME Module::Pluggable - automatically give your module the ability to have plugins =head1 SYNOPSIS Simple use Module::Pluggable - package MyClass; use Module::Pluggable; and then later ... use MyClass; my $mc = MyClass->new(); # returns the names of all plugins installed under MyClass::Plugin::* my @plugins = $mc->plugins(); =head1 EXAMPLE Why would you want to do this? Say you have something that wants to pass an object to a number of different plugins in turn. For example you may want to extract meta-data from every email you get sent and do something with it. Plugins make sense here because then you can keep adding new meta data parsers and all the logic and docs for each one will be self contained and new handlers are easy to add without changing the core code. For that, you might do something like ... package Email::Examiner; use strict; use Email::Simple; use Module::Pluggable require => 1; sub handle_email { my $self = shift; my $email = shift; foreach my $plugin ($self->plugins) { $plugin->examine($email); } return 1; } .. and all the plugins will get a chance in turn to look at it. This can be trivially extended so that plugins could save the email somewhere and then no other plugin should try and do that. Simply have it so that the C method returns C<1> if it has saved the email somewhere. You might also want to be paranoid and check to see if the plugin has an C method. foreach my $plugin ($self->plugins) { next unless $plugin->can('examine'); last if $plugin->examine($email); } And so on. The sky's the limit. =head1 DESCRIPTION Provides a simple but, hopefully, extensible way of having 'plugins' for your module. Obviously this isn't going to be the be all and end all of solutions but it works for me. Essentially all it does is e