Merge pull request #721 from jazzband/through-defaults-2

CHANGELOG.rst

@@ -12,6 +12,9 @@ Unreleased
 * Add Django 3.2 support.
 
 
+* Add support for custom fields on through table models with `through_defaults` for ``TaggedManager.add`` and ``TaggedManager.set``.
+
+
 1.3.0 (2020-05-19)
 ~~~~~~~~~~~~~~~~~~
 

docs/api.rst

@@ -12,7 +12,7 @@ playing around with the API.
         information.
     :param blank: Controls whether this field is required.
 
-    .. method:: add(*tags)
+    .. method:: add(*tags, through_defaults=None, tag_kwargs=None)
 
         This adds tags to an object. The tags can be either ``Tag`` instances, or
         strings::
@@ -21,6 +21,12 @@ playing around with the API.
             []
             >>> apple.tags.add("red", "green", "fruit")
 
+        Use the ``through_defaults`` argument to specify values for your custom
+        ``through`` model, if needed.
+
+        The ``tag_kwargs`` argument allows one to specify parameters for the tags
+        themselves.
+
     .. method:: remove(*tags)
 
         Removes a tag from an object. No exception is raised if the object
@@ -30,12 +36,15 @@ playing around with the API.
 
         Removes all tags from an object.
 
-    .. method:: set(*tags, clear=False)
+    .. method:: set(*tags, through_defaults=None, clear=False)
 
         If ``clear = True`` removes all the current tags and then adds the
         specified tags to the object. Otherwise sets the object's tags to those
         specified, removing only the missing tags and adding only the new tags.
 
+        Use the ``through_defaults`` argument to specify values for your custom
+        ``through`` model, if needed.
+
     .. method: most_common()
 
         Returns a ``QuerySet`` of all tags, annotated with the number of times

taggit/managers.py

@@ -56,6 +56,8 @@ def clone(self):
 
 
 class _TaggableManager(models.Manager):
+    # TODO investigate whether we can use a RelatedManager instead of all this stuff
+    # to take advantage of all the Django goodness
     def __init__(self, through, model, instance, prefetch_cache_name):
         super().__init__()
         self.through = through
@@ -143,9 +145,10 @@ def _lookup_kwargs(self):
         return self.through.lookup_kwargs(self.instance)
 
     @require_instance_manager
-    def add(self, *tags, **kwargs):
-        tag_kwargs = kwargs.pop("tag_kwargs", {})
+    def add(self, *tags, through_defaults=None, tag_kwargs=None, **kwargs):
 
+        if tag_kwargs is None:
+            tag_kwargs = {}
         db = router.db_for_write(self.through, instance=self.instance)
 
         tag_objs = self._to_tag_model_instances(tags, tag_kwargs)
@@ -173,7 +176,7 @@ def add(self, *tags, **kwargs):
 
         for tag in tag_objs:
             self.through._default_manager.using(db).get_or_create(
-                tag=tag, **self._lookup_kwargs()
+                tag=tag, **self._lookup_kwargs(), defaults=through_defaults
             )
 
         signals.m2m_changed.send(
@@ -252,7 +255,7 @@ def slugs(self):
         return self.get_queryset().values_list("slug", flat=True)
 
     @require_instance_manager
-    def set(self, *tags, **kwargs):
+    def set(self, *tags, through_defaults=None, **kwargs):
         """
         Set the object's tags to the given n tags. If the clear kwarg is True
         then all existing tags are removed (using `.clear()`) and the new tags
@@ -289,7 +292,7 @@ def set(self, *tags, **kwargs):
                     new_objs.append(obj)
 
             self.remove(*old_tag_strs)
-            self.add(*new_objs, **kwargs)
+            self.add(*new_objs, through_defaults=through_defaults, **kwargs)
 
     @require_instance_manager
     def remove(self, *tags):

tests/migrations/0001_initial.py

@@ -315,6 +315,7 @@ class Migration(migrations.Migration):
                         to="tests.OfficialTag",
                     ),
                 ),
+                ("extra_field", models.CharField(max_length=10)),
             ],
         ),
         migrations.CreateModel(

tests/models.py

@@ -260,6 +260,7 @@ class OfficialThroughModel(GenericTaggedItemBase):
     tag = models.ForeignKey(
         OfficialTag, related_name="tagged_items", on_delete=models.CASCADE
     )
+    extra_field = models.CharField(max_length=10)
 
     class Meta:
         unique_together = [["content_type", "object_id", "tag"]]

tests/tests.py

@@ -661,6 +661,19 @@ def test_taggeditem_str(self):
             str(self.taggeditem_model.objects.first()), "apple tagged with juicy"
         )
 
+    def test_taggeditem_through_defaults(self):
+        if self.taggeditem_model != OfficialThroughModel:
+            self.skipTest(
+                "Through default tests are only run when the tagged item model has extra_field"
+            )
+        apple = self.food_model.objects.create(name="kiwi")
+        apple.tags.add("juicy", through_defaults={"extra_field": "green"})
+
+        self.assertEqual(
+            str(self.taggeditem_model.objects.first()), "kiwi tagged with juicy"
+        )
+        self.assertEqual(self.taggeditem_model.objects.first().extra_field, "green")
+
     def test_abstract_subclasses(self):
         p = Photo.objects.create()
         p.tags.add("outdoors", "pretty")