apeiron

NAME

Module::Pluggable::Ordered - Call module plugins in a specified order

SYNOPSIS

    package Foo;
    use Module::Pluggable::Ordered;

    Foo->call_plugins("some_event", @stuff);

        for my $plugin (Foo->plugins()){
                $plugin->method();
        }

Meanwhile, in a nearby module...

    package Foo::Plugin::One;
    sub some_event_order { 99 } # I get called last of all
    sub some_event { my ($self, @stuff) = @_; warn "Hello!" }

        sub _order { 99 } # I get listed by plugins_ordered() last

And in another:

    package Foo::Plugin::Two;
    sub some_event_order { 13 } # I get called relatively early
    sub some_event { ... }

        sub _order { 10 } # I get listed by plugins_ordered() early

DESCRIPTION

This module behaves exactly the same as Module::Pluggable, supporting all of its options, but also mixes in the call_plugins and plugins_ordered methods to your class. call_plugins acts a little like Class::Trigger; it takes the name of a method, and some parameters. Let's say we call it like so:

    __PACKAGE__->call_plugins("my_method", @something);

call_plugins looks at the plugin modules found using Module::Pluggable for ones which provide my_method_order. It sorts the modules numerically based on the result of this method, and then calls $_->my_method(@something) on them in order. This produces an effect a little like the System V init process, where files can specify where in the init sequence they want to be called.

plugins_ordered extends the plugins method created by Module::Pluggable to list the plugins in defined order. It looks for a _order method in the modules found using Module::Pluggable, and returns the modules sorted numerically in that order. For example:

        my @plugins = __PACKAGE__->plugins();

The resulting array of plugins will be sorted. If no _order subroutine is defined for a module, an arbitrary default value of 50 is used.

OPTIONS

The package option can be used to put the pluggability into another package, to be used for modules building on the functionality of this one.

It also provides the only and except options.

     # will only return the Foo::Plugin::Quux plugin
     use Module::Pluggable::Ordered only => [ "Foo::Plugin::Quux" ];

     # will not return the Foo::Plugin::Quux plugin
     use Module::Pluggable::Ordered except => [ "Foo::Plugin::Quux" ];

SEE ALSO

Module::Pluggable, Class::Trigger

AUTHOR

Simon Cozens, <simon@cpan.org> (author emeritus)

Christopher Nehren, <apeiron@cpan.org> (current maintainer)

Please report bugs via the CPAN RT tracker at http://rt.cpan.org.

COPYRIGHT AND LICENSE

Copyright 2004 by Simon Cozens

Copyright 2004 by Christopher Nehren (current copyright holder)

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

ACKNOWLEDGEMENTS

Thank you to Simon Cozens for originally writing this module.

Thanks to Lars Thegler for indirectly alerting me to the fact that my POD was horribly broken, for providing patches to make this module work with Perl versions < 5.6, for maintaining the port up to version 1.3, and for allowing me to take maintainership for versions 1.3 onwards.




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