[fix] Fixed CopyableFieldsAdmin fields order openwisp#335

Fixes openwisp#335

Author: Aryamanz29

openwisp_utils/admin.py

@@ -104,15 +104,19 @@ def get_fields(self, request, obj=None):
         # in the case of `add_view` because `copyable_fields`
         # can't be edited and are auto generated by the system
         if not obj:
-            return tuple(set(fields).difference(self.copyable_fields))
+            # Make sure field order remains the same when excluding `copyable_fields`
+            return [field for field in fields if field not in self.copyable_fields]
         return fields
 
     def get_readonly_fields(self, request, obj=None):
         readonly_fields = super(ModelAdmin, self).get_readonly_fields(request, obj)
         if not obj:
             return readonly_fields
-        # Make sure `copyable_fields` is included in `read_only` fields
-        return tuple([*readonly_fields, *self.copyable_fields])
+        # If any `copyable_fields` are not included
+        # in the `read-only` fields, then include them
+        if not any(field in readonly_fields for field in self.copyable_fields):
+            return tuple([*readonly_fields, *self.copyable_fields])
+        return readonly_fields
 
     def add_view(self, request, form_url='', extra_context=None):
         extra_context = extra_context or {}

tests/test_project/tests/test_admin.py

@@ -234,6 +234,18 @@ class TestCopyableFieldAdmin(CopyableFieldsAdmin):
             ma.get_fields(self.client.request)
         self.assertIn(copyable_field_err, err.exception.args[0])
 
+    def test_copyablefields_admin_fields_order(self):
+        path = reverse('admin:test_project_project_add')
+        self.client.get(path)
+        ma = ProjectAdmin(Project, self.site)
+        # 'uuid' should be missing from ma.get_fields()
+        # because we're testing the project admin add form,
+        # and now we're adding it here again only to assert the admin field order
+        self.assertEqual(ma.fields, ('uuid', *ma.get_fields(self.client.request)))
+        self.assertEqual(
+            ma.readonly_fields, ma.get_readonly_fields(self.client.request)
+        )
+
     def test_receive_url_admin(self):
         p = Project.objects.create(name='test_receive_url_admin_project')
         ma = ProjectAdmin(Project, self.site)