X-Git-Url: http://git.kaliko.me/?a=blobdiff_plain;f=doc%2Fsource%2Fuse.rst;h=86c3e724416db7ef13eb3cd7cfbbf5e22c8419c8;hb=HEAD;hp=213491ed7d29b39097c90ba8d4bb300cd73bad31;hpb=11078491b9ccbafa03d5070309aeb89a195e9bc0;p=python-musicpd.git diff --git a/doc/source/use.rst b/doc/source/use.rst index 213491e..88728ef 100644 --- a/doc/source/use.rst +++ b/doc/source/use.rst @@ -16,43 +16,84 @@ The client library can be used as follows: # test ${XDG_RUNTIME_DIR}/mpd/socket for existence # fallback to localhost:6600 # connect support host/port argument as well - print(client.mpd_version) # print the mpd protocol version - print(client.cmd('foo', 42)) # print result of the request "cmd foo 42" - # (nb. for actual command, see link to the protocol below) + print(client.mpd_version) # print the MPD protocol version + client.setvol('42') # sets the volume client.disconnect() # disconnect from the server -In the example above `cmd` in not an actual MPD command, for a list of -supported commands, their arguments (as MPD currently understands -them), and the functions used to parse their responses see :ref:`commands`. +The MPD command protocol exchanges line-based text records. The client emits a +command with optional arguments. In the example above the client sends a +`setvol` command with the string argument `42`. -See the `MPD protocol documentation`_ for more details. +MPD commands are exposed as :py:class:`musicpd.MPDClient` methods. Methods +**arguments are python strings**. Some commands are composed of more than one word +(ie "**tagtypes [disable|enable|all]**"), for these use a `snake case`_ style to +access the method. Then **"tagtypes enable"** command is called with +**"tagtypes_enable"**. + +Remember MPD protocol is text based, then all MPD command arguments are UTF-8 +strings. In the example above, an integer can be used as argument for the +`setvol` command, but it is then evaluated as a string when the command is +written to the socket. To avoid confusion use regular string instead of relying +on object string representation. + +:py:class:`musicpd.MPDClient` methods returns different kinds of objects +depending on the command. Could be :py:obj:`None`, a single object as a +:py:obj:`str` or a :py:obj:`dict`, a list of :py:obj:`dict`. + +Then :py:class:`musicpd.MPDClient` **methods signatures** are not hard coded +within this module since the protocol is handled on the server side. Please +refer to the protocol and MPD commands in `MPD protocol documentation`_ to +learn how to call commands and what kind of arguments they expect. + +Some examples are provided for the most common cases, see :ref:`examples`. + +For a list of currently supported commands in this python module see +:ref:`commands`. .. _environment_variables: Environment variables --------------------- -The client honors the following environment variables: +:py:class:`musicpd.MPDClient` honors the following environment variables: + +.. envvar:: MPD_HOST + + MPD host (:abbr:`FQDN (fully qualified domain name)`, IP, socket path or abstract socket) and password. + + | To define a **password** set :envvar:`MPD_HOST` to "*password@host*" (password only "*password@*") + | For **abstract socket** use "@" as prefix : "*@socket*" and then with a password "*pass@@socket*" + | Regular **unix socket** are set with an absolute path: "*/run/mpd/socket*" + +.. envvar:: MPD_PORT - * ``MPD_HOST`` MPD host (:abbr:`FQDN (fully qualified domain name)`, socket path or abstract socket) and password. + MPD port, relevant for TCP socket only - | To define a password set MPD_HOST to "`password@host`" (password only "`password@`") - | For abstract socket use "@" as prefix : "`@socket`" and then with a password "`pass@@socket`" - | Regular unix socket are set with an absolute path: "`/run/mpd/socket`" - * ``MPD_PORT`` MPD port, relevant for TCP socket only, ie with :abbr:`FQDN (fully qualified domain name)` defined host - * ``MPD_TIMEOUT`` timeout for connecting to MPD and waiting for MPD’s response in seconds - * ``XDG_RUNTIME_DIR`` path to look for potential socket: ``${XDG_RUNTIME_DIR}/mpd/socket`` +.. envvar:: MPD_TIMEOUT + + socket timeout when connecting to MPD and waiting for MPD’s response (in seconds) + +.. envvar:: XDG_RUNTIME_DIR + + path to look for potential socket .. _default_settings: Default settings ---------------- - * If ``MPD_HOST`` is not set, then look for a socket in ``${XDG_RUNTIME_DIR}/mpd/socket`` - * If there is no socket use ``localhost`` - * If ``MPD_PORT`` is not set, then use ``6600`` - * If ``MPD_TIMEOUT`` is not set, then uses :py:obj:`musicpd.CONNECTION_TIMEOUT` +Default host: + * use :envvar:`MPD_HOST` environment variable if set, extract password if present, + * else use :envvar:`XDG_RUNTIME_DIR` to looks for an existing file in ``${XDG_RUNTIME_DIR}/mpd/socket``, :envvar:`XDG_RUNTIME_DIR` defaults to ``/run`` if not set. + * else set host to ``localhost`` + +Default port: + * use :envvar:`MPD_PORT` environment variable if set + * else use ``6600`` +Default timeout: + * use :envvar:`MPD_TIMEOUT` if set + * else use :py:obj:`musicpd.CONNECTION_TIMEOUT` Context manager --------------- @@ -90,7 +131,7 @@ Some commands (e.g. delete) allow specifying a range in the form `"START:END"` ( Possible ranges are: `"START:END"`, `"START:"` and `":"` : -Instead of giving the plain string as `"START:END"`, you **can** provide a :py:obj:`tuple` as `(START,END)`. The module is then ensuring the format is correct and raises an :py:obj:`musicpd.CommandError` exception otherwise. Empty start or end can be specified as en empty string `''` or :py:obj:`None`. +Instead of giving the plain string as `"START:END"`, you **can** provide a :py:obj:`tuple` as `(START,END)`. The module is then ensuring the format is correct and raises an :py:obj:`musicpd.CommandError` exception otherwise. Empty start or end can be specified as en empty string ``''`` or :py:obj:`None`. .. code-block:: python @@ -102,8 +143,8 @@ Instead of giving the plain string as `"START:END"`, you **can** provide a :py:o # missing end interpreted as highest value possible, pay attention still need a tuple. client.delete((pos,)) # purge queue from current to the end -A notable case is the `rangeid` command allowing an empty range specified -as a single colon as argument (i.e. sending just ":"): +A notable case is the *rangeid* command allowing an empty range specified +as a single colon as argument (i.e. sending just ``":"``): .. code-block:: python @@ -112,7 +153,7 @@ as a single colon as argument (i.e. sending just ":"): Empty start in range (i.e. ":END") are not possible and will raise a CommandError. -Remember the of the tuple is optional, range can still be specified as single string `START:END`. In case of malformed range a CommandError is still raised. +.. note:: Remember the use of a tuple is **optional**. Range can still be specified as a plain string ``"START:END"``. Iterators ---------- @@ -177,7 +218,7 @@ Fetching album covers is possible with albumart, here is an example: >>> print('something went wrong', file=sys.stderr) >>> cli.disconnect() -A `CommandError` is raised if the album does not expose a cover. +A :py:obj:`musicpd.CommandError` is raised if the album does not expose a cover. You can also use `readpicture` command to fetch embedded picture: @@ -272,6 +313,20 @@ triggering a socket timeout unless the connection is actually lost (actually it could also be that MPD took too much time to answer, but MPD taking more than a couple of seconds for these commands should never occur). +.. _exceptions: + +Exceptions +---------- + +The :py:obj:`connect` method raises +:py:obj:`ConnectionError` only (an :py:obj:`MPDError` exception) but then, calling other MPD commands, the module can raise +:py:obj:`MPDError` or an :py:obj:`OSError` depending on the error and +where it occurs. + +Then using musicpd module both :py:obj:`musicpd.MPDError` and :py:obj:`OSError` +exceptions families are expected, see :ref:`examples` for a +way to deal with this. .. _MPD protocol documentation: http://www.musicpd.org/doc/protocol/ +.. _snake case: https://en.wikipedia.org/wiki/Snake_case .. vim: spell spelllang=en