audio: Add simple parsers for m3u, pls, xspf and uri lists.

These parsers, and the detectors should probably be moved out at some point,
but for now the simple version of these will do.

mopidy/audio/playlists.py

@@ -4,6 +4,8 @@ import pygst
 pygst.require('0.10')
 import gst
 
+import ConfigParser as configparser
+import xml.etree.ElementTree
 import xml.dom.pulldom
 
 
@@ -35,6 +37,36 @@ def detect_xspf_header(typefind):
     return False
 
 
+def parse_m3u(data):
+    # TODO: convert non uris to file uris.
+    for line in data.readlines():
+        if not line.startswith('#') and line.strip():
+            yield line
+
+
+def parse_pls(data):
+    # TODO: error handling of bad playlists.
+    # TODO: convert non uris to file uris.
+    cp = configparser.RawConfigParser()
+    cp.readfp(data)
+    for i in xrange(1, cp.getint('playlist', 'numberofentries')):
+        yield cp.get('playlist', 'file%d' % i)
+
+
+def parse_xspf(data):
+    # TODO: handle parser errors
+    root = xml.etree.ElementTree.fromstring(data.read())
+    tracklist = tree.find('{http://xspf.org/ns/0/}trackList')
+    for track in tracklist.findall('{http://xspf.org/ns/0/}track'):
+        yield track.findtext('{http://xspf.org/ns/0/}location')
+
+
+def parse_urilist(data):
+    for line in data.readlines():
+        if not line.startswith('#') and line.strip():
+            yield line
+
+
 def playlist_typefinder(typefind, func, caps):
     if func(typefind):
         typefind.suggest(gst.TYPE_FIND_MAXIMUM, caps)