man Module::Pluggable::Ordered (3): 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" ];

AUTHOR

Simon Cozens, <[email protected]> (author emeritus)

Christopher Nehren, <[email protected]> (current maintainer)

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

COPYRIGHT AND LICENSE

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.