NAME
    Event::RPC - Event based transparent Client/Server RPC framework

SYNOPSIS
      #-- Server Code
      use Event::RPC::Server;
      use My::TestModule;
      my $server = Event::RPC::Server->new (
          port    => 5555,
          classes => { "My::TestModule" => { ... } },
      );
      $server->start;

      ----------------------------------------------------------
  
      #-- Client Code
      use Event::RPC::Client;
      my $client = Event::RPC::Client->new (
          server   => "localhost",
          port     => 5555,
      );
      $client->connect;

      #-- Call methods of My::TestModule on the server
      my $obj = My::TestModule->new ( foo => "bar" );
      my $foo = $obj->get_foo;

ABSTRACT
    Event::RPC supports you in developing Event based networking
    client/server applications with transparent object/method access from
    the client to the server. Network communication is optionally encrypted
    using IO::Socket::SSL. Several event loop managers are supported due to
    an extensible API. Currently Event, Glib and AnyEvent are implemented.
    The latter lets you use nearly every event loop implementation available
    for Perl. AnyEvent was invented after Event::RPC was created and thus
    Event::RPC started using it's own abstraction model.

DESCRIPTION
    Event::RPC consists of a server and a client library. The server exports
    a list of classes and methods, which are allowed to be called over the
    network. More specific it acts as a proxy for objects created on the
    server side (on demand of the connected clients) which handles client
    side methods calls with transport of method arguments and return values.

    The object proxy handles refcounting and destruction of objects created
    by clients properly. Objects as method parameters and return values are
    handled as well (although with some limitations, see below).

    For the client the whole thing is totally transparent - once connected
    to the server it doesn't know whether it calls methods on local or
    remote objects.

    Also the methods on the server newer know whether they are called
    locally or from a connected client. Your application logic is not
    affected by Event::RPC at all, at least if it has a rudimentary clean OO
    design.

    For details on implementing servers and clients please refer to the man
    pages of Event::RPC::Server and Event::RPC::Client.

REQUIREMENTS
    Event::RPC needs either one of the following modules on the server
    (they're not necessary on the client):

      Event
      Glib
      AnyEvent

    They're needed for event handling resp. mainloop implementation. If you
    like to use SSL encryption you need to install

      IO::Socket::SSL

    Event::RPC needs minimum one of the following modules for data
    serialisation:

      Sereal (::Decoder and ::Encoder)
      CBOR::XS
      JSON::XS
      Storable

    Server and client negotiate automatically which serialiser to use to
    achieve maximum compatibility.

    Some words about the Storable module: it's known to be insecure, so
    Event::RPC uses it as the last option. You can even prevent Event::RPC
    from using it at all (even when it's installed, which is the case for
    nearly every Perl installation) - check manpages of Event::Server and
    Event::Client about the details.

    In case you use Storable take care that both client and server use
    exactly the same version of the Storable module! Otherwise Event::RPC
    client/server communication will fail badly.

INSTALLATION
    You get the latest installation tarballs and online documentation at
    this location:

      http://www.exit1.org/Event-RPC/

    If your system meets the requirements mentioned above, installation is
    just:

      perl Makefile.PL
      make test
      make install

    To test a specific Event loop implementation, export the variable
    EVENT_RPC_LOOP:

      export EVENT_RPC_LOOP=Event::RPC::Loop::Glib
      make test

    Otherwise Event::RPC will fallback to the most appropriate module
    installed on your system.

EXAMPLES
    The tarball includes an examples/ directory which contains two programs:

      server.pl
      client.pl

    Just execute them with --help to get the usage. They do some very simple
    communication but are good to test your setup, in particular in a mixed
    environment.

LIMITATIONS
    Although the classes and objects on the server are accessed
    transparently by the client there are some limitations should be aware
    of. With a clean object oriented design these should be no problem in
    real applications:

  Direct object data manipulation is forbidden
    All objects reside on the server and they keep there! The client just
    has specially wrapped proxy objects, which trigger the necessary magic
    to access the object's methods on the server. Complete objects are never
    transferred from the server to the client, so something like this does
    not work:

      $object->{data} = "changed data";

    (assuming $object is a hash ref on the server).

    Only method calls are transferred to the server, so even for "simple"
    data manipulation a method call is necessary:

      $object->set_data ("changed data");

    As well for reading an object attribute. Accessing a hash key will fail:

      my $data = $object->{data};

    Instead call a method which returns the 'data' member:

      my $data = $object->get_data;

  Methods may exchange objects, but not in a too complex structure
    Event::RPC handles methods which return objects. The only requirement is
    that they are declared as a Object returner on the server (refer to
    Event::RPC::Server for details), but not if the object is hidden inside
    a deep complex data structure.

    An array or hash ref of objects is Ok, but not more. This would require
    to much expensive runtime data inspection.

    Object receiving parameters are more restrictive, since even hiding them
    inside one array or hash ref is not allowed. They must be passed as a
    direkt argument of the method subroutine.

AUTHORS
      Jörn Reder <joern AT zyn.de>

COPYRIGHT AND LICENSE
    Copyright (C) 2005-2015 by Jörn Reder <joern AT zyn.de>.

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

