José Joaquín Atria

NAME

AnyEvent::Net::MPD - A non-blocking interface to MPD

SYNOPSIS

  use AnyEvent::Net::MPD;

  my $mpd = AnyEvent::Net::MPD->new( host => $ARGV[0] )->connect;

  my @subsystems = qw( player mixer database );

  # Register a listener
  foreach my $subsystem (@subsystems) {
    $mpd->on( $subsystem => sub {
      my ($self) = @_;
      print "$subsystem has changed\n";

      # Stop listening if mixer changes
      $mpd->noidle if $subsystem eq 'mixer';
    });
  }

  # Send a command
  my $stats = $mpd->send( 'stats' );

  # Or in blocking mode
  my $status = $mpd->send( 'status' )->recv;

  # Which is the same as
  $status = $mpd->get( 'status' );

  print "Server is ", $status->{state}, " state\n";
  print "Server has ", $stats->recv->{albums}, " albums in the database\n";

  # Put the client in looping idle mode
  my $idle = $mpd->idle( @subsystems );

  # Set the emitter in motion, until the next call to noidle
  $idle->recv;

DESCRIPTION

AnyEvent::Net::MPD provides a non-blocking interface to an MPD server.

ATTRIBUTES

host

The host to connect to. Defaults to localhost.

port

The port to connect to. Defaults to 6600.

password

The password to use to connect to the server. Defaults to undefined, which means to use no password.

auto_connect

If set to true, the constructor will block until the connection to the MPD server has been established. Defaults to false.

METHODS

connect

If the client is not connected, wait until it is. Otherwise, do nothing. Returns the client itself;

send $cmd
send $cmd => @args
send [ $cmd1 $cmd2 $cmd3 ]

Send a command to the server in a non-blocking way. This command always returns an AnyEvent condvar.

If called with a single string, then that string will be sent as the command.

If called with a list, the list will be joined with spaces and sent as the command.

If called with an array reference, then the value of each of item in that array will be processed as above (with array references instead of plain lists). If the referenced array contains more than one command, then these will be sent to the server as a command list.

An optional subroutine reference passed as the last argument will be passed to the condvar constructor, and fire when the condvar is ready (= when there is a response from the server).

The response from the server will be parsed with a command-specific parser, to provide some structure to the flat lists returned by MPD. If no parser is found, or if the user specifically asks for no parser to be used (see below), then the response will be an array reference with the raw lines from the server.

Finally, a hash reference with additional options can be passed as the first argument. Valid keys to use are:

parser

Specify the parser to use for the response. Parser labels are MPD commands. If the requested parser is not found, the fallback none will be used.

Alternatively, if the value itself is a code reference, then that will be called with a reference to the raw list of lines as its only argument.

For ease of use, underscores in the final command name will be removed before sending to the server (unless the command name requires them).

get

Send a command in a blocking way. Internally calls send and immediately waits for the response.

idle

Put the client in idle loop. This sends the idle command and registers an internal listener that will put the client back in idle mode after each server response.

If called with a list of subsystem names, then the client will only listen to those subsystems. Otherwise, it will listen to all of them.

If you are using this module for an event-based application (see below), this will configure the client to fire the events at the appropriate times.

Returns an AnyEvent condvar. Blocking on this conditional variable will wait until the next call to noidle (see below).

noidle

Cancel the client's idle mode. Sends an undefined value to the condvar created by idle and breaks the internal idle loop.

EVENTS

After calling idle, the client will be in idle mode, which means that any changes to the specified subsystemswill trigger a signal. When the client receives this signal, it will fire an event named as the subsystem that fired it.

The event will be fired with the client as the first argument, and the response from the server as the second argument. This can safely be ignored, since the server response will normally just hold the name of the subsystem that changed, which you already know.

Event descriptions

database

The song database has been changed after update.

udpate

A database update has started or finished. If the database was modified during the update, the database event is also emitted.

stored_playlist

A stored playlist has been modified, renamed, created or deleted.

playlist

The current playlist has been modified.

player

The player has been started stopped or seeked.

mixer

The volume has been changed.

output

An audio output has been added, removed or modified (e.g. renamed, enabled or disabled)

options

Options like repeat, random, crossfade, replay gain.

partition

A partition was added, removed or changed.

sticker

The sticket database has been modified.

subscription

A client has subscribed or unsubscribed from a channel.

message

A message was received on a channel this client is subscribed to.

SEE ALSO

  • Net::MPD

    A lightweight blocking MPD library. Has fewer dependencies than this one, but it does not curently support command lists. I took the idea of allowing for underscores in command names from this module.

  • Audio::MPD

    The first MPD library on CPAN. This one also blocks and is based on Moose. However, it seems to be unmaintained at the moment.

  • Dancer::Plugin::MPD

    A Dancer plugin to connect to MPD. Haven't really tried it, since I haven't used Dancer...

  • POE::Component::Client::MPD

    A POE component to connect to MPD. This uses Audio::MPD in the background.

AUTHOR

  • José Joaquín Atria <jjatria@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2017 by José Joaquín Atria.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.