zero: Can delete embedded images

Fixes #1100.

beetsplug/zero.py

@@ -17,7 +17,7 @@
 import re
 import logging
 from beets.plugins import BeetsPlugin
-from beets.library import Item
+from beets.mediafile import MediaFile
 from beets.importer import action
 from beets.util import confit
 
@@ -51,7 +51,7 @@ class ZeroPlugin(BeetsPlugin):
                 log.warn(u'[zero] field \'{0}\' ignored, zeroing '
                          u'it would be dangerous'.format(field))
                 continue
-            if field not in Item._fields.keys():
+            if field not in MediaFile.fields():
                 log.error(u'[zero] invalid field: {0}'.format(field))
                 continue
 
@@ -59,7 +59,7 @@ class ZeroPlugin(BeetsPlugin):
                 self.patterns[field] = self.config[field].as_str_seq()
             except confit.NotFoundError:
                 # Matches everything
-                self.patterns[field] = [u'']
+                self.patterns[field] = True
 
     def import_task_choice_event(self, session, task):
         """Listen for import_task_choice event."""
@@ -73,23 +73,29 @@ class ZeroPlugin(BeetsPlugin):
         """Check if field (as string) is matching any of the patterns in
         the list.
         """
+        if patterns is True:
+            return True
         for p in patterns:
             if re.search(p, unicode(field), flags=re.IGNORECASE):
                 return True
         return False
 
     def write_event(self, item, path, tags):
-        """Listen for write event."""
+        """Set values in tags to `None` if the key and value are matched
+        by `self.patterns`.
+        """
         if not self.patterns:
             log.warn(u'[zero] no fields, nothing to do')
             return
 
         for field, patterns in self.patterns.items():
-            if field not in tags:
-                log.error(u'[zero] no such field: {0}'.format(field))
-                continue
-
+            if field in tags:
                 value = tags[field]
-            if self.match_patterns(value, patterns):
+                match = self.match_patterns(tags[field], patterns)
+            else:
+                value = ''
+                match = patterns is True
+
+            if match:
                 log.debug(u'[zero] {0}: {1} -> None'.format(field, value))
                 tags[field] = None

docs/changelog.rst

@@ -10,6 +10,7 @@ New:
   files as they are imported. Thanks to :user:`xsteadfastx`. :bug:`1098`
 * A new :doc:`/plugins/plexupdate` lets you notify a `Plex`_ server when the
   database changes. Thanks again to xsteadfastx. :bug:`1120`
+* :doc:`/plugins/zero` can remove embedded images.
 
 Fixed:
 

docs/plugins/zero.rst

@@ -16,7 +16,9 @@ Make a ``zero:`` section in your configuration file. You can specify the
 fields to nullify and the conditions for nullifying them:
 
 * Set ``fields`` to a whitespace-separated list of fields to change. You can
-  get the list of all available fields by running ``beet fields``.
+  get the list of all available fields by running ``beet fields``. In
+  addition, the ``images`` field allows you to remove any images
+  embedded in the media file.
 * To conditionally filter a field, use ``field: [regexp, regexp]`` to specify
   regular expressions.
 

test/helper.py

@@ -47,7 +47,7 @@ import beets.plugins
 from beets.library import Library, Item, Album
 from beets import importer
 from beets.autotag.hooks import AlbumInfo, TrackInfo
-from beets.mediafile import MediaFile
+from beets.mediafile import MediaFile, Image
 
 # TODO Move AutotagMock here
 import _common
@@ -346,18 +346,33 @@ class TestHelper(object):
             items.append(item)
         return self.lib.add_album(items)
 
-    def create_mediafile_fixture(self, ext='mp3'):
+    def create_mediafile_fixture(self, ext='mp3', images=[]):
         """Copies a fixture mediafile with the extension to a temporary
         location and returns the path.
 
         It keeps track of the created locations and will delete the with
         `remove_mediafile_fixtures()`
+
+        `images` is a subset of 'png', 'jpg', and 'tiff'. For each
+        specified extension a cover art image is added to the media
+        file.
         """
         src = os.path.join(_common.RSRC, 'full.' + ext)
         handle, path = mkstemp()
         os.close(handle)
         shutil.copyfile(src, path)
 
+        if images:
+            mediafile = MediaFile(path)
+            imgs = []
+            for img_ext in images:
+                img_path = os.path.join(_common.RSRC,
+                                        'image-2x3.{0}'.format(img_ext))
+                with open(img_path, 'rb') as f:
+                    imgs.append(Image(f.read()))
+            mediafile.images = imgs
+            mediafile.save()
+
         if not hasattr(self, '_mediafile_fixtures'):
             self._mediafile_fixtures = []
         self._mediafile_fixtures.append(path)

test/test_zero.py

@@ -82,6 +82,20 @@ class ZeroPluginTest(unittest.TestCase, TestHelper):
         self.assertEqual(item['year'], 2000)
         self.assertIsNone(mediafile.year)
 
+    def test_album_art(self):
+        path = self.create_mediafile_fixture(images=['jpg'])
+        item = Item.from_path(path)
+
+        mediafile = MediaFile(item.path)
+        self.assertNotEqual(0, len(mediafile.images))
+
+        config['zero'] = {'fields': ['images']}
+        self.load_plugins('zero')
+
+        item.write()
+        mediafile = MediaFile(item.path)
+        self.assertEqual(0, len(mediafile.images))
+
 
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)