Network.MPD

An MPD client library. MPD is a daemon for playing music that is controlled over a network socket. Its site is at http://www.musicpd.org/.

To avoid name clashes with the standard Prelude functions, do:

 import qualified Network.MPD as MPD

Basic data types

class (Monad m, MonadError MPDError m) => MonadMPD m where

A typeclass to allow for multiple implementations of a connection to an MPD server.

Methods

close :: m ()

Close the connection.

Instances

MonadMPD MPD

data MPD a

The main implementation of an MPD client. It actually connects to a server and interacts with it.

To use the error throwing/catching capabilities:

 import Control.Monad.Error (throwError, catchError)

To run IO actions within the MPD monad:

 import Control.Monad.Trans (liftIO)

Instances

Monad MPD

Functor MPD

Applicative MPD

MonadIO MPD

MonadMPD MPD

MonadError MPDError MPD

data MPDError

The MPDError type is used to signal errors, both from the MPD and otherwise.

Constructors

NoMPD

MPD not responding

TimedOut

The connection timed out

Unexpected String

MPD returned an unexpected response. This is a bug, either in the library or in MPD itself.

Custom String

Used for misc. errors

ACK ACKType String

ACK type and a message from the server

Instances

Eq MPDError

Show MPDError

Error MPDError

MonadError MPDError MPD

data ACKType

Represents various MPD errors (aka. ACKs).

Constructors

InvalidArgument

Invalid argument passed (ACK 2)

InvalidPassword

Invalid password supplied (ACK 3)

Auth

Authentication required (ACK 4)

UnknownCommand

Unknown command (ACK 5)

FileNotFound

File or directory not found ACK 50)

PlaylistMax

Playlist at maximum size (ACK 51)

System

A system error (ACK 52)

PlaylistLoad

Playlist loading failed (ACK 53)

Busy

Update already running (ACK 54)

NotPlaying

An operation requiring playback got interrupted (ACK 55)

FileExists

File already exists (ACK 56)

UnknownACK

An unknown ACK (aka. bug)

Instances

Eq ACKType

type Response = Either MPDError

A response is either an MPDError or some result.

type Host = String

type Port = Integer

type Password = String

Connections

withMPD :: MPD a -> IO (Response a)

A wrapper for withMPDEx that uses localhost:6600 as the default host:port, or whatever is found in the environment variables MPD_HOST and MPD_PORT. If MPD_HOST is of the form "password@host" the password will be supplied as well.

Examples:

 withMPD $ play Nothing
 withMPD $ add_ "tool" >> play Nothing >> currentSong

withMPDEx :: Host -> Port -> Password -> MPD a -> IO (Response a)

The most configurable API for running an MPD action.

Command related data types

type Artist = String

type Album = String

type Title = String

type PlaylistName = String

Used for commands which require a playlist name. If empty, the current playlist is used.

type Path = String

Used for commands which require a path within the database. If empty, the root path is used.

data Meta

Available metadata types/scope modifiers, used for searching the database for entries with certain metadata values.

Constructors

Artist

Album

Title

Track

Name

Genre

Date

Composer

Performer

Disc

Any

Filename

Instances

Show Meta

MPDArg Meta

data ObjectType

Object types.

Constructors

SongObj

Instances

Eq ObjectType

Show ObjectType

MPDArg ObjectType

type Seconds = Integer

data PLIndex

Represents a song's playlist index.

Constructors

Pos Integer

A playlist position index (starting from 0)

ID Integer

A playlist ID number that more robustly identifies a song.

Instances

Eq PLIndex

Show PLIndex

data State

Represents the different playback states.

Constructors

Playing

Stopped

Paused

Instances

Eq State

Show State

data Subsystem

Represents the various MPD subsystems.

Constructors

Database

The song database

Update

Database updates

StoredPlaylist

Stored playlists

Playlist

The current playlist

Player

The player

Mixer

The volume mixer

Output

Audio outputs

Options

Playback options

Instances

Eq Subsystem

Show Subsystem

MPDArg Subsystem

data ReplayGainMode

Constructors

Off

Disable replay gain

TrackMode

Per track mode

AlbumMode

Per album mode

Instances

Eq ReplayGainMode

Show ReplayGainMode

MPDArg ReplayGainMode

data Count

Represents the result of running count.

Constructors

Count

Fields

cSongs :: Integer

Number of songs matching the query

cPlaytime :: Seconds

Total play time of matching songs

Instances

Eq Count

Show Count

defaultCount :: Count

data Device

Represents an output device.

Constructors

Device

Fields

dOutputID :: Int

Output's ID number

dOutputName :: String

Output's name as defined in the MPD configuration file

dOutputEnabled :: Bool

Instances

Eq Device

Show Device

defaultDevice :: Device

data Stats

Container for database statistics.

Constructors

Stats

Fields

stsArtists :: Integer

Number of artists.

stsAlbums :: Integer

Number of albums.

stsSongs :: Integer

Number of songs.

stsUptime :: Seconds

Daemon uptime in seconds.

stsPlaytime :: Seconds

Total playing time.

stsDbPlaytime :: Seconds

Total play time of all the songs in the database.

stsDbUpdate :: Integer

Last database update in UNIX time.

Instances

Eq Stats

Show Stats

defaultStats :: Stats

data Song

Represents a single song item.

Constructors

Song

Auxiliary song fields

Fields

sgArtist :: String

sgAlbum :: String

sgTitle :: String

sgFilePath :: String

sgGenre :: String

sgName :: String

sgComposer :: String

sgPerformer :: String

sgLength :: Seconds

Length in seconds

sgDate :: Int

Year

sgTrack :: (Int, Int)

Track number/total tracks

sgDisc :: Maybe (Int, Int)

Position in set/total in set

sgIndex :: Maybe PLIndex

sgAux :: [(String, String)]

Instances

Eq Song

Show Song

defaultSong :: Song

data Status

Container for MPD status.

Constructors

Status

Fields

stState :: State

stVolume :: Int

A percentage (0-100)

stRepeat :: Bool

stRandom :: Bool

stPlaylistVersion :: Integer

A value that is incremented by the server every time the playlist changes.

stPlaylistLength :: Integer

The number of items in the current playlist.

stSongPos :: Maybe PLIndex

Current song's position in the playlist.

stSongID :: Maybe PLIndex

Current song's playlist ID.

stNextSongPos :: Maybe PLIndex

Next song's position in the playlist.

stNextSongID :: Maybe PLIndex

Next song's playlist ID.

stTime :: (Seconds, Seconds)

Time elapsed/total time.

stBitrate :: Int

Bitrate (in kilobytes per second) of playing song (if any).

stXFadeWidth :: Seconds

Crossfade time.

stAudio :: (Int, Int, Int)

Samplerate/bits/channels for the chosen output device (see mpd.conf).

stUpdatingDb :: Integer

Job ID of currently running update (if any).

stSingle :: Bool

If True, MPD will play only one song and stop after finishing it.

stConsume :: Bool

If True, a song will be removed after it has been played.

stError :: String

Last error message (if any).

Instances

Eq Status

Show Status

defaultStatus :: Status

Query interface

data Query

An interface for creating MPD queries.

For example, to match any song where the value of artist is "Foo", we use:

 Artist =? "Foo"

We can also compose queries, thus narrowing the search. For example, to match any song where the value of artist is "Foo" and the value of album is "Bar", we use:

 Artist =? "Foo" <&> Album =? "Bar"

Instances

Show Query

Monoid Query

MPDArg Query

(=?) :: Meta -> String -> Query

Create a query.

(<&>) :: Query -> Query -> Query

Combine queries.

anything :: Query

An empty query. Matches anything.

Querying MPD's status

clearError :: MonadMPD m => m ()

Clear the current error message in status.

currentSong :: (Functor m, MonadMPD m) => m (Maybe Song)

Get the currently playing song.

idle :: MonadMPD m => m [Subsystem]

Wait until there is a noteworthy change in one or more of MPD's susbystems. Note that running this command will block until either idle returns or is cancelled by noidle.

noidle :: MonadMPD m => m ()

Cancel idle.

status :: MonadMPD m => m Status

Get the server's status.

stats :: MonadMPD m => m Stats

Get server statistics.

Playback options

consume :: MonadMPD m => Bool -> m ()

Set consume mode

crossfade :: MonadMPD m => Seconds -> m ()

Set crossfading between songs.

random :: MonadMPD m => Bool -> m ()

Set random playing.

repeat :: MonadMPD m => Bool -> m ()

Set repeating.

setVolume :: MonadMPD m => Int -> m ()

Set the volume (0-100 percent).

single :: MonadMPD m => Bool -> m ()

Set single mode

replayGainMode :: MonadMPD m => ReplayGainMode -> m ()

Set the replay gain mode.

replayGainStatus :: MonadMPD m => m [String]

Get the replay gain options.

Controlling playback

next :: MonadMPD m => m ()

Play the next song.

pause :: MonadMPD m => Bool -> m ()

Pause playing.

play :: MonadMPD m => Maybe PLIndex -> m ()

Begin/continue playing.

previous :: MonadMPD m => m ()

Play the previous song.

seek :: MonadMPD m => Maybe PLIndex -> Seconds -> m ()

Seek to some point in a song. Seeks in current song if no position is given.

stop :: MonadMPD m => m ()

Stop playing.

The current playlist

add :: MonadMPD m => Path -> m [Path]

Like add_ but returns a list of the files added.

add_ :: MonadMPD m => Path -> m ()

Add a song (or a whole directory) to the current playlist.

addId

Arguments

:: MonadMPD m

=> Path

-> Maybe Integer

Optional playlist position

-> m Integer

Like add, but returns a playlist id.

clear :: MonadMPD m => m ()

Clear the current playlist.

delete :: MonadMPD m => PLIndex -> m ()

Remove a song from the current playlist.

move :: MonadMPD m => PLIndex -> Integer -> m ()

Move a song to a given position in the current playlist.

playlist :: MonadMPD m => m [(PLIndex, Path)]

Retrieve file paths and positions of songs in the current playlist. Note that this command is only included for completeness sake; it's deprecated and likely to disappear at any time, please use playlistInfo instead.

playlistFind :: MonadMPD m => Query -> m [Song]

Search for songs in the current playlist with strict matching.

playlistInfo :: MonadMPD m => Maybe (Either PLIndex (Int, Int)) -> m [Song]

Retrieve metadata for songs in the current playlist.

playlistSearch :: MonadMPD m => Query -> m [Song]

Search case-insensitively with partial matches for songs in the current playlist.

plChanges :: MonadMPD m => Integer -> m [Song]

Retrieve a list of changed songs currently in the playlist since a given playlist version.

plChangesPosId :: MonadMPD m => Integer -> m [(PLIndex, PLIndex)]

Like plChanges but only returns positions and ids.

shuffle

Arguments

:: MonadMPD m

=> Maybe (Int, Int)

Optional range (start, end)

-> m ()

Shuffle the playlist.

swap :: MonadMPD m => PLIndex -> PLIndex -> m ()

Swap the positions of two songs. Note that the positions must be of the same type, i.e. mixing Pos and ID will result in a no-op.

Stored playlist

listPlaylist :: MonadMPD m => PlaylistName -> m [Path]

Retrieve a list of files in a given playlist.

listPlaylistInfo :: MonadMPD m => PlaylistName -> m [Song]

Retrieve metadata for files in a given playlist.

listPlaylists :: MonadMPD m => m [PlaylistName]

Retreive a list of stored playlists.

load :: MonadMPD m => PlaylistName -> m ()

Load an existing playlist.

playlistAdd :: MonadMPD m => PlaylistName -> Path -> m [Path]

Like playlistAdd but returns a list of the files added.

playlistAdd_ :: MonadMPD m => PlaylistName -> Path -> m ()

Add a song (or a whole directory) to a stored playlist. Will create a new playlist if the one specified does not already exist.

playlistClear :: MonadMPD m => PlaylistName -> m ()

Clear a playlist. If the specified playlist does not exist, it will be created.

playlistDelete

Arguments

:: MonadMPD m

=> PlaylistName

-> Integer

Playlist position

-> m ()

Remove a song from a playlist.

playlistMove :: MonadMPD m => PlaylistName -> Integer -> Integer -> m ()

Move a song to a given position in the playlist specified.

rename

Arguments

:: MonadMPD m

=> PlaylistName

Original playlist

-> PlaylistName

New playlist name

-> m ()

Rename an existing playlist.

rm :: MonadMPD m => PlaylistName -> m ()

Delete existing playlist.

save :: MonadMPD m => PlaylistName -> m ()

Save the current playlist.

The music database

count :: MonadMPD m => Query -> m Count

Count the number of entries matching a query.

find :: MonadMPD m => Query -> m [Song]

Search the database for entries exactly matching a query.

findAdd :: MonadMPD m => Query -> m ()

Adds songs matching a query to the current playlist.

list

Arguments

:: MonadMPD m

=> Meta

Metadata to list

-> Query

-> m [String]

List all metadata of metadata (sic).

listAll :: MonadMPD m => Path -> m [Path]

List the songs (without metadata) in a database directory recursively.

listAllInfo :: MonadMPD m => Path -> m [Either Path Song]

Recursive lsInfo.

lsInfo :: MonadMPD m => Path -> m [Either Path Song]

Non-recursively list the contents of a database directory.

search :: MonadMPD m => Query -> m [Song]

Search the database using case insensitive matching.

update :: MonadMPD m => [Path] -> m ()

Update the server's database. If no paths are given, all paths will be scanned. Unreadable or non-existent paths are silently ignored.

rescan :: MonadMPD m => [Path] -> m ()

Like update but also rescans unmodified files.

Stickers

stickerGet

Arguments

:: MonadMPD m

=> ObjectType

-> String

Object URI

-> String

Sticker name

-> m [String]

Reads a sticker value for the specified object.

stickerSet

Arguments

:: MonadMPD m

=> ObjectType

-> String

Object URI

-> String

Sticker name

-> String

Sticker value

-> m ()

Adds a sticker value to the specified object.

stickerDelete

Arguments

:: MonadMPD m

=> ObjectType

-> String

Object URI

-> String

Sticker name

-> m ()

Delete a sticker value from the specified object.

stickerList

Arguments

:: MonadMPD m

=> ObjectType

-> String

Object URI

-> m [(String, String)]

Sticker name/sticker value

Lists the stickers for the specified object.

stickerFind

Arguments

:: MonadMPD m

=> ObjectType

-> String

Path

-> String

Sticker name

-> m [(String, String)]

URI/sticker value

Searches the sticker database for stickers with the specified name, below the specified path.

Connection

close :: MonadMPD m => m ()

Close the connection.

kill :: MonadMPD m => m ()

Kill the server. Obviously, the connection is then invalid.

password :: MonadMPD m => String -> m ()

Send password to server to authenticate session. Password is sent as plain text.

ping :: MonadMPD m => m ()

Check that the server is still responding.

Audio output devices

disableOutput :: MonadMPD m => Int -> m ()

Turn off an output device.

enableOutput :: MonadMPD m => Int -> m ()

Turn on an output device.

outputs :: MonadMPD m => m [Device]

Retrieve information for all output devices.

Reflection

commands :: MonadMPD m => m [String]

Retrieve a list of available commands.

notCommands :: MonadMPD m => m [String]

Retrieve a list of unavailable (due to access restrictions) commands.

tagTypes :: MonadMPD m => m [String]

Retrieve a list of available song metadata.

urlHandlers :: MonadMPD m => m [String]

Retrieve a list of supported urlhandlers.

decoders :: MonadMPD m => m [(String, [(String, String)])]

Retreive a list of decoder plugins with associated suffix and mime types.

Extensions/shortcuts

addMany :: MonadMPD m => PlaylistName -> [Path] -> m ()

Add a list of songs/folders to a playlist. Should be more efficient than running add many times.

deleteMany :: MonadMPD m => PlaylistName -> [PLIndex] -> m ()

Delete a list of songs from a playlist. If there is a duplicate then no further songs will be deleted, so take care to avoid them (see prune for this).

complete :: MonadMPD m => String -> m [Either Path Song]

Returns all songs and directories that match the given partial path name.

crop :: MonadMPD m => Maybe PLIndex -> Maybe PLIndex -> m ()

Crop playlist. The bounds are inclusive. If Nothing is passed the cropping will leave your playlist alone on that side. Using ID will automatically find the absolute playlist position and use that as the cropping boundary.

prune :: MonadMPD m => m ()

Remove duplicate playlist entries.

lsDirs :: MonadMPD m => Path -> m [Path]

List directories non-recursively.

lsFiles :: MonadMPD m => Path -> m [Path]

List files non-recursively.

lsPlaylists :: MonadMPD m => m [PlaylistName]

List all playlists.

listArtists :: MonadMPD m => m [Artist]

List the artists in the database.

listAlbums :: MonadMPD m => Maybe Artist -> m [Album]

List the albums in the database, optionally matching a given artist.

listAlbum :: MonadMPD m => Artist -> Album -> m [Song]

List the songs in an album of some artist.

getPlaylist :: MonadMPD m => m [Song]

Retrieve the current playlist. Equivalent to playlistinfo Nothing.

toggle :: MonadMPD m => m ()

Toggles play/pause. Plays if stopped.

updateId :: MonadMPD m => [Path] -> m Integer

Like update, but returns the update job id.

volume :: MonadMPD m => Int -> m ()

Increase or decrease volume by a given percent, e.g. 'volume 10' will increase the volume by 10 percent, while 'volume (-10)' will decrease it by the same amount.