Support ordering tags by specified field

taggit/managers.py

@@ -58,12 +58,16 @@ 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):
+    def __init__(self, through, model, instance, prefetch_cache_name, ordering=None):
         super().__init__()
         self.through = through
         self.model = model
         self.instance = instance
         self.prefetch_cache_name = prefetch_cache_name
+        if ordering:
+            self.ordering = ordering
+        else:
+            self.ordering = []
 
     def is_cached(self, instance):
         return self.prefetch_cache_name in instance._prefetched_objects_cache
@@ -73,7 +77,9 @@ def get_queryset(self, extra_filters=None):
             return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
         except (AttributeError, KeyError):
             kwargs = extra_filters if extra_filters else {}
-            return self.through.tags_for(self.model, self.instance, **kwargs)
+            return self.through.tags_for(self.model, self.instance, **kwargs).order_by(
+                *self.ordering
+            )
 
     def get_prefetch_queryset(self, instances, queryset=None):
         if queryset is not None:
@@ -429,6 +435,7 @@ def __init__(
         blank=False,
         related_name=None,
         to=None,
+        ordering=None,
         manager=_TaggableManager,
     ):
         self.through = through or TaggedItem
@@ -444,6 +451,7 @@ def __init__(
             rel=rel,
         )
 
+        self.ordering = ordering
         self.swappable = False
         self.manager = manager
 
@@ -458,6 +466,7 @@ def __get__(self, instance, model):
             model=model,
             instance=instance,
             prefetch_cache_name=self.name,
+            ordering=self.ordering,
         )
 
     def deconstruct(self):

tests/migrations/0005_auto_20210713_2301.py

@@ -0,0 +1,38 @@
+# Generated by Django 3.2.4 on 2021-06-19 08:26
+
+from django.db import migrations, models
+
+import taggit.managers
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("tests", "0004_auto_20210619_0826"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="OrderedModel",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "tags",
+                    taggit.managers.TaggableManager(
+                        help_text="A comma-separated list of tags.",
+                        through="taggit.TaggedItem",
+                        to="taggit.Tag",
+                        verbose_name="Tags",
+                    ),
+                ),
+            ],
+        ),
+    ]

tests/models.py

@@ -408,3 +408,7 @@ class Meta:
 # 	HINT: Rename field 'Tag.name', or add/change a related_name argument to the definition for field 'Name.tags'.
 class Name(models.Model):
     tags = TaggableManager(related_name="a_unique_related_name")
+
+
+class OrderedModel(models.Model):
+    tags = TaggableManager(ordering=["name"])

tests/tests.py

@@ -46,6 +46,7 @@
     OfficialPet,
     OfficialTag,
     OfficialThroughModel,
+    OrderedModel,
     Pet,
     Photo,
     ProxyPhoto,
@@ -1262,3 +1263,14 @@ def test_custom_related_name(self):
         name.tags.add("foo")
         tag = Tag.objects.get(a_unique_related_name=name.pk)
         self.assertEqual(tag.name, "foo")
+
+
+class OrderedTagsTest(TestCase):
+    def test_added_tags_are_returned_ordered(self):
+        obj = OrderedModel.objects.create()
+        obj.tags.add("green", "red", "orange", "yellow", "blue")
+
+        self.assertListEqual(
+            ["blue", "green", "orange", "red", "yellow"],
+            list(obj.tags.values_list("name", flat=True)),
+        )