- NAME
- SYNOPSIS
- DESCRIPTION
- HOWTO
  - Registering Plugin Modules
  - Registering Plugin Commands
  - Registering Plugin Help
  - Arguments to Plugin Commands
- BUG REPORTS
- AUTHOR
- COPYRIGHT
- SEE ALSO

# NAME

CPANPLUS::Shell::Default::Plugins::HOWTO -- documentation on how to write your own plugins

# SYNOPSIS

        package CPANPLUS::Shell::Default::Plugins::MyPlugin;

        ### return command => method mapping
        sub plugins { ( myplugin1 => 'mp1', myplugin2 => 'mp2' ) }

        ### method called when the command '/myplugin1' is issued
        sub mp1 { .... }

        ### method called when the command '/? myplugin1' is issued
        sub mp1_help { return "Help Text" }

# DESCRIPTION

This pod text explains how to write your own plugins for `CPANPLUS::Shell::Default`.

# HOWTO

## Registering Plugin Modules

Plugins are detected by using `Module::Pluggable`. Every module in the `CPANPLUS::Shell::Default::Plugins::*` namespace is considered a plugin, and is attempted to be loaded.

Therefor, any plugin must be declared in that namespace, in a corresponding `.pm` file.

## Registering Plugin Commands

To register any plugin commands, a list of key value pairs must be returned by a `plugins` method in your package. The keys are the commands you wish to register, the values are the methods in the plugin package you wish to have called when the command is issued.

For example, a simple 'Hello, World!' plugin:

        package CPANPLUS::Shell::Default::Plugins::HW;

        sub plugins { return ( helloworld => 'hw' ) };

        sub hw { print "Hello, world!\n" }

When the user in the default shell now issues the `/helloworld` command, this command will be dispatched to the plugin, and its `hw` method will be called

## Registering Plugin Help

To provide usage information for your plugin, the user of the default shell can type `/? PLUGIN_COMMAND`. In that case, the function `PLUGIN_COMMAND_help` will be called in your plugin package.

For example, extending the above example, when a user calls `/? helloworld`, the function `hw_help` will be called, which might look like this:

        sub hw_help { "    /helloworld      # prints "Hello, world!\n" }

If you dont provide a corresponding _help function to your commands, the default shell will handle it gracefully, but the user will be stuck without usage information on your commands, so it's considered undesirable to omit the help functions.

## Arguments to Plugin Commands

Any plugin function will receive the following arguments when called, which are all positional:

Classname -- The name of your plugin class
Shell -- The CPANPLUS::Shell::Default object
Backend -- The CPANPLUS::Backend object
Command -- The command issued by the user
Input -- The input string from the user
Options -- A hashref of options provided by the user

For example, the following command:

        /helloworld bob --nofoo --bar=2 joe

Would yield the following arguments:

        sub hw {
            my $class   = shift;    # CPANPLUS::Shell::Default::Plugins::HW
            my $shell   = shift;    # CPANPLUS::Shell::Default object
            my $cb      = shift;    # CPANPLUS::Backend object
            my $cmd     = shift;    # 'helloworld'
            my $input   = shift;    # 'bob joe'
            my $opts    = shift;    # { foo => 0, bar => 2 }

            ....
        }

# BUG REPORTS

Please report bugs or other issues to <bug-cpanplus@rt.cpan.org<gt>.

# AUTHOR

This module by Jos Boumans <kane@cpan.org>.

# COPYRIGHT

The CPAN++ interface (of which this module is a part of) is copyright (c) 2001 - 2007, Jos Boumans <kane@cpan.org>. All rights reserved.

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

# SEE ALSO

CPANPLUS::Shell::Default, CPANPLUS::Shell, cpanp