core: Add 'include_tracks' argument to 'get_playlists()'

Conflicts:
	docs/changes.rst

docs/changes.rst

@@ -24,6 +24,15 @@ v0.11.2 (UNRELEASED)
 
 - Make ``mopidy-scan`` support symlinks.
 
+**Core API**
+
+- :meth:`mopidy.core.PlaylistsController.get_playlists` now accepts an argument
+  ``include_tracks``. This defaults to :class:`True`, which has the same old
+  behavior. If set to :class:`False`, the tracks are stripped from the
+  playlists before they are returned. This can be used to limit the amount of
+  data returned if the response is to be passed out of the application, e.g. to
+  a web client. (Fixes: :issue:`297`)
+
 
 v0.11.1 (2012-12-24)
 ====================

mopidy/core/playlists.py

@@ -15,11 +15,14 @@ class PlaylistsController(object):
         self.backends = backends
         self.core = core
 
-    def get_playlists(self):
+    def get_playlists(self, include_tracks=True):
         futures = [
             b.playlists.playlists for b in self.backends.with_playlists]
         results = pykka.get_all(futures)
-        return list(itertools.chain(*results))
+        playlists = list(itertools.chain(*results))
+        if not include_tracks:
+            playlists = [p.copy(tracks=[]) for p in playlists]
+        return playlists
 
     playlists = property(get_playlists)
     """

tests/core/playlists_test.py

@@ -46,6 +46,22 @@ class PlaylistsTest(unittest.TestCase):
         self.assertIn(self.pl2a, result)
         self.assertIn(self.pl2b, result)
 
+    def test_get_playlists_includes_tracks_by_default(self):
+        result = self.core.playlists.get_playlists()
+
+        self.assertEqual(result[0].name, 'A')
+        self.assertEqual(len(result[0].tracks), 1)
+        self.assertEqual(result[1].name, 'B')
+        self.assertEqual(len(result[1].tracks), 1)
+
+    def test_get_playlist_can_strip_tracks_from_returned_playlists(self):
+        result = self.core.playlists.get_playlists(include_tracks=False)
+
+        self.assertEqual(result[0].name, 'A')
+        self.assertEqual(len(result[0].tracks), 0)
+        self.assertEqual(result[1].name, 'B')
+        self.assertEqual(len(result[1].tracks), 0)
+
     def test_create_without_uri_scheme_uses_first_backend(self):
         playlist = Playlist()
         self.sp1.create().get.return_value = playlist

tests/utils/jsonrpc_test.py

@@ -603,7 +603,7 @@ class JsonRpcInspectorTest(JsonRpcTestBase):
 
         self.assertIn('core.playlists.get_playlists', methods)
         self.assertEquals(
-            len(methods['core.playlists.get_playlists']['params']), 0)
+            len(methods['core.playlists.get_playlists']['params']), 1)
 
         self.assertIn('core.tracklist.filter', methods.keys())
         self.assertEquals(