New all_keys() method on dbcore.Model

Rather than the ad-hoc one on library classes. This also avoids some confusing
duplication in the `beet fields` output, at the cost of turning off the plugin
distinction.

beets/dbcore/db.py

@@ -271,6 +271,13 @@ class Model(object):
         else:
             return base_keys
 
+    @classmethod
+    def all_keys(self):
+        """Get a list of available keys for objects of this type.
+        Includes fixed and computed fields.
+        """
+        return list(self._fields) + self._getters().keys()
+
     # Act like a dictionary.
 
     def update(self, values):

beets/library.py

@@ -479,15 +479,6 @@ class Item(LibModel):
         i.mtime = i.current_mtime()  # Initial mtime.
         return i
 
-    @classmethod
-    def get_fields(cls):
-        """Returns Item fields available for queries and format strings."""
-        plugin_fields = []
-        for plugin in plugins.find_plugins():
-            plugin_fields += plugin.template_fields.keys()
-        return (cls._fields.keys() + cls._getters().keys() +
-                cls._types.keys()), plugin_fields
-
     def __setitem__(self, key, value):
         """Set the item's value for a standard field or a flexattr.
         """
@@ -910,15 +901,6 @@ class Album(LibModel):
         getters['albumtotal'] = Album._albumtotal
         return getters
 
-    @classmethod
-    def get_fields(cls):
-        """Returns Album fields available for queries and format strings."""
-        plugin_fields = []
-        for plugin in plugins.find_plugins():
-            plugin_fields += plugin.album_template_fields.keys()
-        return (cls._fields.keys() + cls._getters().keys() +
-                cls._types.keys()), plugin_fields
-
     def items(self):
         """Returns an iterable over the items associated with this
         album.

beets/ui/commands.py

@@ -82,17 +82,11 @@ def fields_func(lib, opts, args):
         names.sort()
         print_("  " + "\n  ".join(names))
 
-    fs, pfs = library.Item.get_fields()
     print_("Item fields:")
-    _print_rows(fs)
-    print_("Template fields from plugins:")
-    _print_rows(pfs)
+    _print_rows(library.Item.all_keys())
 
-    fs, pfs = library.Album.get_fields()
     print_("Album fields:")
-    _print_rows(fs)
-    print_("Template fields from plugins:")
-    _print_rows(pfs)
+    _print_rows(library.Album.all_keys())
 
 
 fields_cmd = ui.Subcommand(

beetsplug/duplicates.py

@@ -237,9 +237,13 @@ class DuplicatesPlugin(BeetsPlugin):
         return counts
 
     def _order(self, objs, tiebreak=None):
-        """Return objs sorted by descending order of fields in tiebreak dict.
+        """Return the objects (Items or Albums) sorted by descending
+        order of priority.
 
-        Default ordering is based on attribute completeness.
+        If provided, the `tiebreak` dict indicates the field to use to
+        prioritize the objects. Otherwise, the objects are placed in
+        order of "completeness": objects with more non-null fields come
+        first.
         """
         if tiebreak:
             kind = 'items' if all(isinstance(o, Item)
@@ -248,7 +252,7 @@ class DuplicatesPlugin(BeetsPlugin):
         else:
             kind = Item if all(isinstance(o, Item) for o in objs) else Album
             if kind is Item:
-                fields = [f for sublist in kind.get_fields() for f in sublist]
+                fields = kind.all_keys()
                 key = lambda x: len([(a, getattr(x, a, None)) for a in fields
                                      if getattr(x, a, None) not in (None, '')])
             else:

docs/changelog.rst

@@ -79,6 +79,8 @@ Fixes:
   bug`_. Thanks to :user:`nathdwek`. :bug:`1545`
 * Fix the :ref:`group_albums` importer mode so it can handle when files are
   not already in order by album. :bug:`1550`
+* The ``fields`` command no longer separates built-in fields from
+  plugin-provided ones. This distinction was becoming increasingly unreliable.
 
 .. _Python bug: http://bugs.python.org/issue16512