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Simple(3)	      User Contributed Perl Documentation	     Simple(3)

NAME
       RPC::Simple - Perl classes to handle simple asynchronous	RPC calls with
       call-back

SYNOPSIS
       Client Side :

	   package MyLocal ;

	   use vars qw($VERSION	@ISA @RPC_SUB $tempObj)	;
	   @ISA	= qw(RPC::Simple::AnyLocal);
	   @RPC_SUB = qw(remoteAsk);

	   sub new
	   {
	       my $type	= shift	;

	       my $self	= {} ;
	       my $remote =  shift ;
	       bless $self,$type ;

	       $self->createRemote($remote,'MyRemote.pm') ;
	       return $self ;
	   }
	   sub answer
	   {
	       my $self	= shift	;
	       my $result = shift ;

	       print "answer is	$result\n" ;
	   }

	   package main	;

	   use RPC::Simple::Factory ;

	   use IO::Socket ;
	   use IO::Select ;

	   my $verbose = 0 ; # you may change this value to see	RPC traffic

	   my $factory = new RPC::Simple::Factory(verbose_ref => \$verbose) ;
	   my $local = new MyLocal($factory) ;
	   $local->remoteAsk(callback => 'answer');

	   my $selector	= IO::Select->new();
	   $selector->add($factory->getSocket());

	   my ($toRead,	undef, undef) =	IO::Select->select($selector, undef, $selector,	10);
	   foreach my $fh (@$toRead)
	   {
	       if($fh == $factory->getSocket())
	       {
		   $factory->readSock();
	       }
	   }

       Server Side :

	   package MyRemote ;

	   use vars qw($VERSION	@ISA @RPC_SUB) ;
	   @ISA	= qw(RPC::Simple::AnyRemote);
	   @RPC_SUB = qw(answer) ;

	   sub remoteAsk
	   {
	       my $self=shift ;
	       my %args	= @_;
	       my $callback = $args{callback} || undef;

	       if (defined $callback)
	       {
		   $self->$callback("Hello local object");
	       }
	   }

	   package main	;

	   use RPC::Simple::Server ;
	   use RPC::Simple::Factory ;

	   my $arg = shift ;

	   my $verbose = 0 ; # you may change this value to see	RPC traffic

	   my $pid = &spawn(undef,$verbose) ; #	spawn server

       See t/connection.t and t/RealMyLocal.pm for more	information.

DESCRIPTION
       This module implements remote procedure call. I've tried	to keep	things
       simple.

       So this module should be	:
	- quite	simple to use (thanks to autoload mechanisms)
	- lightweight

       It sure is not :
	- DCE
	- CORBA
	- bulletproof
	- securityproof
	- foolproof

       But it works. (Although I'm opened to suggestion	regarding the "un-
       proof" areas)

       The module is made of the following sub-classes :

	RPC::Simple::Agent - Perl extension for	an agent object
	RPC::Simple::AnyLocal -	Perl extension defining	a virtual RPC client class

	RPC::Simple::AnyRemote - Perl base class for a remote object
	RPC::Simple::CallHandler - Perl	class to handle	RPC::Simple calls with call-back
	RPC::Simple::Factory - Perl extension for creating client
	RPC::Simple::ObjectHandler - Perl class	to handle a remote object
	RPC::Simple::Server - Perl class to use	in the RPC::Simple server script.
	RPC::Simple::AnyWhere -	Common parts for AnyLocal and AnyRemote

       Anyway, the casual user should worry only about inheriting the
       RPC::Simple::AnyLocal class and creating	a RPC::Simple::Factory on the
       local side.

       On the remote side, the user will only have to inherit
       RPC::Simple::AnyRemote and run the mainLoop method of
       RPC::Simple::Server.

       In each side you	must declare all methods available on the other	side
       in a global array of your class.

       How it works ? The user (i.e. you) must write a local class which
       inherits	from AnyLocal. AnyLocal	is designed to handle Agent and
       Factory.

	   AnyLocal --1---<>---1-- Agent --*--<>---Factory----<>--LAN
	       |
	      /\____
		   |
		   |
	       LocalClass

       First, the user script will have	to :
	- instantiate one Factory.
	- Create its instance of LocalClass
	- LocalClass::new will call $self->createRemote, this will create the
       Agent class.

	- Now any call to an undefined method (BUT declared in @RPC_SUB)
       of LocalClass will be forwarded to the Remote class.
       If this call has	a code reference as first parameter, Agent
       will call this code when	the remote call	is over. I.e. all remote
       procedure call must be designed in asynchronous mode.

       Note that undefined method not declared in @RPC_SUB will	lead to	an
       error. Autoloading is no	longer supported (unless someone complains
       loudly).

       Note that Factory and Agent can use Tk to manage	the socket connection,
       but thisis no longer required..

       On the remote side, the user will write its RemoteClass which will
       inherit from AnyRemote.

	   LAN --1--<>--*-- Server --1--<>--*--ObjectHandler--1--<>--*--CallHandler
						     |			      |
						     1			      *
						     |			      |
						     --<>--1--AnyRemote--1-<>--
								  |
								 /\____
								      |
								      |
								 RemoteClass

       RemoteClass will	be called with the method name that was	invoked	for
       LocalClass. RemtoteClass	may call a function from local class using the
       same mechanism but it may NOT expect a call-back	from this call to the
       local side.

       Note that the remote class may call directly method from	the Local
       class.  (Provided the local method is declared in the @RPC_SUB array of
       the remote class)

       Note that the instance variable of the local class or remote class are
       not shared or updated or	replicated magically. If you must pass data
       from one	side to	the other, you have to do it explicitely. In most case
       you'll pass the variable	value as a method parameter.

CAVEATS
       Well, this stuff	is supposed to be pretty simple, the code to handle
       the RPC and callback is not very	complicated, but I sure	have a lot of
       problem to write	a doc which make using this module simple. Future
       version may get better depending	on your	comments or questions.

THANKS
	   Mike	South <msouth@fulcrum.org>

AUTHORS
	   Current Maintainer
	   Clint Edwards <cedwards@mcclatchyinteractive.com>

	   Original
	   Dominique Dumont, <Dominique_Dumont@grenoble.hp.com>

SEE ALSO
       perl(1),	RPC::Simple::AnyLocal(3), RPC::Simple::AnyRemote(3) .

perl v5.24.1			  2006-05-31			     Simple(3)

NAME | SYNOPSIS | DESCRIPTION | CAVEATS | THANKS | AUTHORS | SEE ALSO

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