Fix when selecting with an MSFList

.github/workflows/tests.yaml

@@ -13,8 +13,6 @@ jobs:
       # and https://docs.djangoproject.com/en/4.2/faq/install/#what-python-version-can-i-use-with-django
       matrix:
         include:
-          - { dj: "4.1.*", py: "3.8" }
-          - { dj: "4.1.*", py: "3.11" }
           - { dj: "4.2.*", py: "3.8" }
           - { dj: "4.2.*", py: "3.12" }
           - { dj: "5.0.*", py: "3.10" }

CHANGES.rst

@@ -1,3 +1,7 @@
+development (unreleased)
+-------------------
+* Fix error with Django>=4.1.3: <https://github.com/goinnn/django-multiselectfield/pull/135>
+
 0.1.12 (2020-02-20)
 -------------------
 

example/app/test_msf_select.py

@@ -0,0 +1,19 @@
+from django.test.testcases import TestCase
+
+from .models import Book
+
+
+class MsfSelectTestCase(TestCase):
+    fixtures = ['app_data.json']
+
+    def test_valid_select(self):
+        """
+        Should be able to use a multiselectfield result to select
+        See
+        https://github.com/goinnn/django-multiselectfield/pull/135
+        """
+        book = Book.objects.first()
+        result = Book.objects.filter(categories=book.categories).only('pk')
+        self.assertEqual(len(result), 1)
+        self.assertEqual(result[0].pk, book.pk)
+        self.assertIn(member='1,3,5', container=str(result.query))

multiselectfield/db/fields.py

@@ -36,17 +36,6 @@ def wrapper(cls):
     return wrapper
 
 
-class MSFList(list):
-
-    def __init__(self, choices, *args, **kwargs):
-        self.choices = choices
-        super(MSFList, self).__init__(*args, **kwargs)
-
-    def __str__(msgl):
-        l = [msgl.choices.get(int(i)) if i.isdigit() else msgl.choices.get(i) for i in msgl]
-        return ', '.join([str(s) for s in l])
-
-
 class MultiSelectField(models.CharField):
     """ Choice values can not contain commas. """
 

multiselectfield/utils.py

@@ -14,6 +14,23 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this programe.  If not, see <http://www.gnu.org/licenses/>.
 
+from __future__ import annotations
+
+from collections import UserList
+from typing import Optional, Union
+
+from django.db.models.sql.query import Query
+
+
+class _FakeSqlVal(UserList):
+
+    contains_aggregate = False
+    contains_column_references = False
+    contains_over_clause = False
+
+    def __str__(self):
+        return ','.join(map(str, self))
+
 
 class MSFList(list):
 
@@ -22,8 +39,20 @@ def __init__(self, choices, *args, **kwargs):
         super(MSFList, self).__init__(*args, **kwargs)
 
     def __str__(msgl):
-        msg_list = [msgl.choices.get(int(i)) if i.isdigit() else msgl.choices.get(i) for i in msgl]
-        return ', '.join([str(s) for s in msg_list])
+        msg_list = [
+            msgl.choices.get(int(i)) if i.isdigit() else msgl.choices.get(i)
+            for i in msgl]
+        return ', '.join(str(s) for s in msg_list)
+
+    def resolve_expression(
+            self, query: Query = None, allow_joins: bool = True,
+            reuse: Optional[bool] = None, summarize: bool = False,
+            for_save: bool = False) -> Union[list, _FakeSqlVal]:
+        if for_save:
+            result = _FakeSqlVal(self)
+        else:
+            result = list(self)
+        return result
 
 
 def get_max_length(choices, max_length, default=200):

setup.py

@@ -18,7 +18,8 @@
 
 import codecs
 import os
-from setuptools import setup, find_packages
+
+from setuptools import find_packages, setup
 
 
 def read(*rnames):