README.txt: give an example that actually works

[python-musicpd.git] / mpd.py

diff --git a/mpd.py b/mpd.py
index 1704b7b7fc1e4b6b820f70fad09a343bb34ece30..315c26210a6877bd31fe8af25055a0342f093651 100644 (file)
--- a/mpd.py
+++ b/mpd.py
@@ -1,5 +1,5 @@
 # Python MPD client library
-# Copyright (C) 2008  J. Alexander Treuman <jat@spatialrift.net>
+# Copyright (C) 2008-2010  J. Alexander Treuman <jat@spatialrift.net>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -38,6 +38,9 @@ class CommandError(MPDError):
 class CommandListError(MPDError):
     pass
 
+class PendingCommandError(MPDError):
+    pass
+
 
 class _NotConnected(object):
     def __getattr__(self, attr):
@@ -131,22 +134,57 @@ class MPDClient(object):
         }
 
     def __getattr__(self, attr):
-        try:
-            retval = self._commands[attr]
-        except KeyError:
+        if attr.startswith("send_"):
+            command = attr.replace("send_", "", 1)
+            wrapper = self._send
+        elif attr.startswith("fetch_"):
+            command = attr.replace("fetch_", "", 1)
+            wrapper = self._fetch
+        else:
+            command = attr
+            wrapper = self._execute
+        if command not in self._commands:
             raise AttributeError("'%s' object has no attribute '%s'" %
                                  (self.__class__.__name__, attr))
-        return lambda *args: self._execute(attr, args, retval)
+        return lambda *args: wrapper(command, args)
 
-    def _execute(self, command, args, retval):
-        if self._command_list is not None and not callable(retval):
-            raise CommandListError("%s not allowed in command list" % command)
+    def _send(self, command, args):
+        if self._command_list is not None:
+            raise CommandListError("Cannot use send_%s in a command list" %
+                                   command)
         self._write_command(command, args)
-        if self._command_list is None:
+        self._pending.append(command)
+
+    def _fetch(self, command, args=None):
+        if self._command_list is not None:
+            raise CommandListError("Cannot use fetch_%s in a command list" %
+                                   command)
+        if not self._pending:
+            raise PendingCommandError("No pending commands to fetch")
+        if self._pending[0] != command:
+            raise PendingCommandError("%s is not the currently "
+                                      "pending command" % command)
+        del self._pending[0]
+        retval = self._commands[command]
+        if callable(retval):
+            return retval()
+
+    def _execute(self, command, args):
+        if self._pending:
+            raise PendingCommandError("Cannot execute %s with "
+                                      "pending commands" % command)
+        retval = self._commands[command]
+        if self._command_list is not None:
+            if not callable(retval):
+                raise CommandListError("%s not allowed in command list" %
+                                        command)
+            self._write_command(command, args)
+            self._command_list.append(retval)
+        else:
+            self._write_command(command, args)
             if callable(retval):
                 return retval()
             return retval
-        self._command_list.append(retval)
 
     def _write_line(self, line):
         self._wfile.write("%s\n" % line)
@@ -215,7 +253,7 @@ class MPDClient(object):
                 if key in delimiters:
                     yield obj
                     obj = {}
-                elif obj.has_key(key):
+                elif key in obj:
                     if not isinstance(obj[key], list):
                         obj[key] = [obj[key], value]
                     else:
@@ -293,6 +331,7 @@ class MPDClient(object):
 
     def _reset(self):
         self.mpd_version = None
+        self._pending = []
         self._command_list = None
         self._sock = None
         self._rfile = _NotConnected()
@@ -350,9 +389,17 @@ class MPDClient(object):
         self._sock.close()
         self._reset()
 
+    def fileno(self):
+        if not self._sock:
+            raise ConnectionError("Not connected")
+        return self._sock.fileno()
+
     def command_list_ok_begin(self):
         if self._command_list is not None:
             raise CommandListError("Already in command list")
+        if self._pending:
+            raise PendingCommandError("Cannot begin command list "
+                                      "with pending commands")
         self._write_command("command_list_ok_begin")
         self._command_list = []