Added slugs method and tests

docs/api.txt

@@ -60,9 +60,15 @@ playing around with the API.
         just an iterable) containing the name of each tag as a string::
 
             >>> apple.tags.names()
-            [u'green', u'red']
-            >>> 'green' in apple.tags.names()
-            True
+            [u'green and juicy', u'red']
+
+    .. method:: slugs()
+
+        Convenience method, returning a ``ValuesListQuerySet`` (basically
+        just an iterable) containing the slug of each tag as a string::
+
+            >>> apple.slugs.names()
+            [u'green-and-juicy', u'red']
 
 Filtering
 ~~~~~~~~~

taggit/managers.py

@@ -176,6 +176,10 @@ class _TaggableManager(models.Manager):
         return self.get_query_set().values_list('name', flat=True)
 
     @require_instance_manager
+    def slugs(self):
+        return self.get_query_set().values_list('slug', flat=True)
+
+    @require_instance_manager
     def set(self, *tags):
         self.clear()
         self.add(*tags)

tests/tests.py

@@ -319,6 +319,12 @@ class TaggableManagerTestCase(BaseTaggingTestCase):
         apple.tags.add('red')
         self.assertEqual(list(apple.tags.names()), ['green', 'red'])
 
+    def test_slugs_method(self):
+        apple = self.food_model.objects.create(name="apple")
+        apple.tags.add('green and juicy')
+        apple.tags.add('red')
+        self.assertEqual(list(apple.tags.slugs()), ['green-and-juicy', 'red'])
+
 
 class TaggableManagerDirectTestCase(TaggableManagerTestCase):
     food_model = DirectFood