Event::RPC::Client(3)

NAME
Event::RPC::Client - Client API to connect to Event::RPC Servers

SYNOPSIS
  use Event::RPC::Client;

  my $rpc_client = Event::RPC::Client->new (
    #-- Required arguments
    host => "localhost",
    port => 5555,

    #-- Optional arguments
    classes   => [ "Event::RPC::Test" ],
    class_map => { "Event::RPC::Test" => "My::Event::RPC::Test" },

    ssl       => 1,
    timeout   => 10,

    auth_user => "fred",
    auth_pass => Event::RPC->crypt("fred",$password),

    error_cb => sub {
      my ($client, $error) = @_;
      print "An RPC error occured: $error\n";
      $client->disconnect;
      exit;
    },
  );

  $rpc_client->connect;

  #-- And now use classes and methods the server
  #-- allows to access via RPC, here My::TestModule
  #-- from the Event::RPC::Server manpage SYNPOSIS.
  my $obj = My::TestModule->new( data => "foobar" );
  print "obj says hello: ".$obj->hello."\n";
  $obj->set_data("new foobar");
  print "updated data: ".$obj->get_data."\n";

  $rpc_client->disconnect;

DESCRIPTION
Use this module to write clients accessing objects and methods exported by a Event::RPC driven server.

Just connect to the server over the network, optionally with SSL and user authentication, and then simply use the exported classes and methods like having them locally in the client.

General information about the architecture of Event::RPC driven applications is collected in the Event::RPC manpage.

The following documentation describes the client connection options in detail.

CONFIGURATION OPTIONS
You need to specify at least the server hostname and TCP port to connect a Event::RPC server instance. If the server requires a SSL connection or user authentication you need to supply the corresponding options as well, otherwise connecting will fail.

All options described here may be passed to the new() constructor of Event::RPC::Client. As well you may set or modify them using set_OPTION style mutators, but not after connect() was called! All options may be read using get_OPTION style accessors.

  REQUIRED OPTIONS
These are necessary to connect the server:

server
    This is the hostname of the server running Event::RPC::Server. Use a IP address or DNS name here.

port
    This is the TCP port the server is listening to.

  NETWORK OPTIONS

timeout
    Specify a timeout (in seconds), which is applied when connecting the server.

  CLASS IMPORT OPTION

classes
    This is reference to a list of classes which should be imported into the client. You get a warning if you request a class which is not exported by the server.

    By default all server classes are imported. Use this feature if your server exports a huge list of classes, but your client doesn't need all of them. This saves memory in the client and connect performance increases.

class_map
    Optionally you can map the class names from the server to a different name on the local client using the class_map hash.

    This is necessary if you like to use the same classes locally and remotely. Imported classes from the server are by default registered under the same name on the client, so this conflicts with local classes named identically.

    On the client you access the remote classes under the name assigned in the class map. For example with this map

      class_map => { "Event::ExecFlow::Job" => "_srv::Event::ExecFlow::Job" }

    you need to write this on the client, if you like to create an object remotely on the server:

      my $server_job = _srv::Event::ExecFlow::Job->new ( ... );

    and this to create an object on the client:

      my $client_job = Event::ExecFlow::Job->new ( ... );

    The server knows nothing of the renaming on client side, so you still write this on the server to create objects there:

      my $job = Event::ExecFlow::Job->new ( ... );

  SSL OPTION
If the server accepts only SSL connections you need to enable ssl here in the client as well:

ssl Set this option to 1 to encrypt the network connection using SSL.

  AUTHENTICATION OPTIONS
If the server requires user authentication you need to set the following options:

auth_user
    A valid username.

auth_pass
    The corresponding password, encrypted using Perl's crypt() function, using the username as the salt.

    Event::RPC has a convenience function for generating such a crypted password, although it's currently just a wrapper around Perl's builtin crypt() function, but probably this changes someday, so better use this method:

      $crypted_pass = Event::RPC->crypt($user, $pass);

If the passed credentials are invalid the Event::RPC::Client->connect() method throws a correspondent exception.

  ERROR HANDLING
Any exceptions thrown on the server during execution of a remote method will result in a corresponding exception on the client. So you can use normal exception handling with eval {} when executing remote methods.

But besides this the network connection between your client and the server may break at any time. This raises an exception as well, but you can override this behaviour with the following attribute:

error_cb
    This subroutine is called if any error occurs in the network communication between the client and the server. The actual Event::RPC::Client object and an error string are passed as arguments.

    This is no generic exception handler for exceptions thrown from the executed methods on the server! If you like to catch such exceptions you need to put an eval {} around your method calls, as you would do for local method calls.

    If you don't specify an error_cb an exception is thrown instead.

METHODS

$rpc_client->connect
    This establishes the configured connection to the server. An exception is thrown if something goes wrong, e.g. server not available, credentials are invalid or something like this.

$rpc_client->disconnect
    Closes the connection to the server. You may omit explicit disconnecting since it's done automatically once the Event::RPC::Client object gets destroyed.

READY ONLY ATTRIBUTES

$rpc_client->get_server_version
    Returns the Event::RPC version number of the server after connecting.

$rpc_client->get_server_protocol
    Returns the Event::RPC protocol number of the server after connecting.

$rpc_client->get_client_version
    Returns the Event::RPC version number of the client.

$rpc_client->get_client_protocol
    Returns the Event::RPC protocol number of the client.

AUTHORS
  Jörn Reder <joern at zyn dot de>

COPYRIGHT AND LICENSE
Copyright (C) 2002-2006 by Joern Reder, All Rights Reserved.

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

POD ERRORS
Hey! The above document had some coding errors, which are explained below:

Around line 677:
    Non-ASCII character seen before =encoding in 'Jörn'. Assuming CP1252