POE::Component::IRC::Plugin(3pm)			User Contributed Perl Documentation			  POE::Component::IRC::Plugin(3pm)

NAME

       POE::Component::IRC::Plugin - Provides plugin constants and documentation for POE::Component::IRC

SYNOPSIS

	# A simple ROT13 'encryption' plugin

	package Rot13;

	use strict;
	use warnings;
	use POE::Component::IRC::Plugin qw( :ALL );

	# Plugin object constructor
	sub new {
	    my $package = shift;
	    return bless {}, $package;
	}

	sub PCI_register {
	    my ($self, $irc) = splice @_, 0, 2;

	    $irc->plugin_register( $self, 'SERVER', qw(public) );
	    return 1;
	}

	# This is method is mandatory but we don't actually have anything to do.
	sub PCI_unregister {
	    return 1;
	}

	sub S_public {
	    my ($self, $irc) = splice @_, 0, 2;

	    # Parameters are passed as scalar-refs including arrayrefs.
	    my $nick	= ( split /!/, ${ $_[0] } )[0];
	    my $channel = ${ $_[1] }->[0];
	    my $msg	= ${ $_[2] };

	    if (my ($rot13) = $msg =~ /^rot13 (.+)/) {
		$rot13 =~ tr[a-zA-Z][n-za-mN-ZA-M];

		# Send a response back to the server.
		$irc->yield( privmsg => $channel => $rot13 );
		# We don't want other plugins to process this
		return PCI_EAT_PLUGIN;
	    }

	    # Default action is to allow other plugins to process it.
	    return PCI_EAT_NONE;
	}

DESCRIPTION

       POE::Component::IRC's plugin system has been released separately as Object::Pluggable. Gleaning at its documentation is advised. The rest
       of this document mostly describes aspects that are specific to POE::Component::IRC's use of Object::Pluggable.

HISTORY

       Certain individuals in #PoE on MAGNet said we didn't need to bloat the PoCo-IRC code...

       BinGOs, the current maintainer of the module, and I heartily agreed that this is a wise choice.

       One example:

       Look at the magnificent new feature in 3.4 -> irc_whois replies! Yes, that is a feature I bet most of us have been coveting for a while, as
       it definitely makes our life easier. It was implemented in 30 minutes or so after a request, the maintainer said. I replied by saying that
       it's a wonderful idea, but what would happen if somebody else asked for a new feature? Maybe thatfeature is something we all would love to
       have, so should it be put in the core? Plugins allow the core to stay lean and mean, while delegating additional functionality to outside
       modules. BinGOs' work with making PoCo-IRC inheritable is wonderful, but what if there were 2 modules which have features that you would
       love to have in your bot? Inherit from both? Imagine the mess...

       Here comes plugins to the rescue :)

       You could say Bot::Pluggable does the job, and so on, but if this feature were put into the core, it would allow PoCo-IRC to be extended
       beyond our wildest dreams, and allow the code to be shared amongst us all, giving us superior bug smashing abilities.

       Yes, there are changes that most of us will moan when we go update our bots to use the new $irc object system, but what if we also used
       this opportunity to improve PoCo-IRC even more and give it a lifespan until Perl8 or whatever comes along? :)

DESCRIPTION

       The plugin system works by letting coders hook into the two aspects of PoCo-IRC:

       o   Data received from the server

       o   User commands about to be sent to the server

       The goal of this system is to make PoCo-IRC so easy to extend, enabling it to Take Over The World! *Just Kidding*

       The general architecture of using the plugins should be:

	# Import the stuff...
	use POE;
	use POE::Component::IRC;
	use POE::Component::IRC::Plugin::ExamplePlugin;

	# Create our session here
	POE::Session->create( ... );

	# Create the IRC session here
	my $irc = POE::Component::IRC->spawn() or die "Oh noooo! $!";

	# Create the plugin
	# Of course it could be something like $plugin = MyPlugin->new();
	my $plugin = POE::Component::IRC::Plugin::ExamplePlugin->new( ... );

	# Hook it up!
	$irc->plugin_add( 'ExamplePlugin', $plugin );

	# OOPS, we lost the plugin object!
	my $pluginobj = $irc->plugin_get( 'ExamplePlugin' );

	# We want a list of plugins and objects
	my $hashref = $irc->plugin_list();

	# Oh! We want a list of plugin aliases.
	my @aliases = keys %{ $irc->plugin_list() };

	# Ah, we want to remove the plugin
	$plugin = $irc->plugin_del( 'ExamplePlugin' );

       The plugins themselves will conform to the standard API described here. What they can do is limited only by imagination and the IRC RFC's
       ;)

	# Import the constants
	use POE::Component::IRC::Plugin qw( :ALL );

	# Our constructor
	sub new {
	    ...
	}

	# Required entry point for PoCo-IRC
	sub PCI_register {
	    my ($self, $irc) = @_;
	    # Register events we are interested in
	    $irc->plugin_register( $self, 'SERVER', qw( 355 kick whatever) );

	    # Return success
	    return 1;
	}

	# Required exit point for PoCo-IRC
	sub PCI_unregister {
	    my ($self, $irc) = @_;

	    # PCI will automatically unregister events for the plugin

	    # Do some cleanup...

	    # Return success
	    return 1;
	}

	# Registered events will be sent to methods starting with IRC_
	# If the plugin registered for SERVER - irc_355
	sub S_355 {
	    my($self, $irc, $line) = @_;

	    # Remember, we receive pointers to scalars, so we can modify them
	    $$line = 'frobnicate!';

	    # Return an exit code
	    return PCI_EAT_NONE;
	}

	# Default handler for events that do not have a corresponding plugin
	# method defined.
	sub _default {
	    my ($self, $irc, $event) = splice @_, 0, 3;

	    print "Default called for $event
";

	    # Return an exit code
	    return PCI_EAT_NONE;
	}

       Plugins can even embed their own POE sessions if they need to do fancy stuff.  Below is a template for a plugin which does just that.

	package POE::Plugin::Template;

	use POE;
	use POE::Component::IRC::Plugin qw( :ALL );

	sub new {
	    my $package = shift;
	    my $self = bless {@_}, $package;
	    return $self;
	}

	sub PCI_register {
	    my ($self, $irc) = splice @_, 0, 2;

	    # We store a ref to the $irc object so we can use it in our
	    # session handlers.
	    $self->{irc} = $irc;

	    $irc->plugin_register( $self, 'SERVER', qw(blah blah blah) );

	    POE::Session->create(
		object_states => [
		    $self => [qw(_start _shutdown)],
		],
	    );

	    return 1;
	}

	sub PCI_unregister {
	    my ($self, $irc) = splice @_, 0, 2;
	    # Plugin is dying make sure our POE session does as well.
	    $poe_kernel->call( $self->{SESSION_ID} => '_shutdown' );
	    delete $self->{irc};
	    return 1;
	}

	sub _start {
	    my ($kernel, $self) = @_[KERNEL, OBJECT];
	    $self->{SESSION_ID} = $_[SESSION]->ID();
	    # Make sure our POE session stays around. Could use aliases but that is so messy :)
	    $kernel->refcount_increment( $self->{SESSION_ID}, __PACKAGE__ );
	    return;
	}

	sub _shutdown {
	    my ($kernel, $self) = @_[KERNEL, OBJECT];
	    $kernel->alarm_remove_all();
	    $kernel->refcount_decrement( $self->{SESSION_ID}, __PACKAGE__ );
	    return;
	}

EVENT TYPES

   SERVER hooks
       Hooks that are targeted toward data received from the server will get the exact same arguments as if it was a normal event, look at the
       PoCo-IRC docs for more information.

       NOTE: Server methods are identified in the plugin namespace by the subroutine prefix of S_*. I.e. an irc_kick event handler would be:

	sub S_kick {}

       The only difference is instead of getting scalars, the hook will get a reference to the scalar, to allow it to mangle the data. This allows
       the plugin to modify data *before* they are sent out to registered sessions.

       They are required to return one of the exit codes so PoCo-IRC will know what to do.

       Names of potential hooks

	001
	socketerr
	connected
	plugin_del
	...

       Keep in mind that they are always lowercased. Check out the OUTPUT EVENTS section of POE::Component::IRC's documentation for the complete
       list of events.

   USER hooks
       These type of hooks have two different argument formats. They are split between data sent to the server, and data sent through DCC
       connections.

       NOTE: User methods are identified in the plugin namespace by the subroutine prefix of U_*. I.e. an irc_kick event handler would be:

	sub U_kick {}

       Hooks that are targeted to user data have it a little harder. They will receive a reference to the raw line about to be sent out. That
       means they will have to parse it in order to extract data out of it.

       The reasoning behind this is that it is not possible to insert hooks in every method in the $irc object, as it will become unwieldy and not
       allow inheritance to work.

       The DCC hooks have it easier, as they do not interact with the server, and will receive references to the arguments specified in the DCC
       plugin documentation regarding dcc commands.

       Names of potential hooks

	kick
	dcc_chat
	ison
	privmsg
	...

       Keep in mind that they are always lowercased, and are extracted from the raw line about to be sent to the irc server. To be able to parse
       the raw line, some RFC reading is in order. These are the DCC events that are not given a raw line, they are:

	dcc	   - $nick, $type, $file, $blocksize, $timeout
	dcc_accept - $cookie, $myfile
	dcc_resume - $cookie
	dcc_chat   - $cookie, @lines
	dcc_close  - $cookie

   _default
       If a plugin has registered for an event but doesn't have a hook method defined for ir, component will attempt to call a plugin's "_default"
       method.	The first parameter after the plugin and irc objects will be the handler name.

	sub _default {
	    my ($self, $irc, $event) = splice @_, 0, 3;

	    # $event will be something like S_public or U_dcc, etc.
	    return PCI_EAT_NONE;
	}

       The "_default" handler is expected to return one of the exit codes so PoCo-IRC will know what to do.

EXIT CODES

   PCI_EAT_NONE
       This means the event will continue to be processed by remaining plugins and finally, sent to interested sessions that registered for it.

   PCI_EAT_CLIENT
       This means the event will continue to be processed by remaining plugins but it will not be sent to any sessions that registered for it.
       This means nothing will be sent out on the wire if it was an USER event, beware!

   PCI_EAT_PLUGIN
       This means the event will not be processed by remaining plugins, it will go straight to interested sessions.

   PCI_EAT_ALL
       This means the event will be completely discarded, no plugin or session will see it. This means nothing will be sent out on the wire if it
       was an USER event, beware!

EXPORTS

       Exports the return constants for plugins to use in @EXPORT_OK Also, the ':ALL' tag can be used to get all of them.

SEE ALSO

       POE::Component::IRC

       Object::Pluggable

       Object::Pluggable::Pipeline

       POE::Session

AUTHOR

       Apocalypse <apocal@cpan.org>

perl v5.14.2							    2011-12-07					  POE::Component::IRC::Plugin(3pm)