Opened 2 years ago

Closed 2 years ago

Last modified 2 years ago

#34129 closed Bug (duplicate)

Admin list_editable failed to edit

Reported by: Djing Owned by: Djing
Component: contrib.admin Version: 3.2
Severity: Normal Keywords:
Cc: Djing Triage Stage: Unreviewed
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description

  1. I have two Manager for my Model, one shows only valid items and another one shows all items, and then I change the model's default manager to the previous one which shows only valid items.
  2. I inherit the ModelAdmin and rewrite get_queryset method to make the queryset use the manager which shows all items.
  3. Add valid field to the list_editable.
  4. Here comes the bug. When all items are valid, it's ok and I can change item to invalid(valid=False) and save. But once there is an invalid item, you can't edit it anymore. It just shows "Please correct the error below" whithout any other message.

Attachments (3)

first_all_valid.jpg (36.3 KB ) - added by Djing 2 years ago.
1. all valid items
second_change_to_invalid.jpg (40.3 KB ) - added by Djing 2 years ago.
2.it's ok to edit item to invalid
third_cannot_edit_anymore.jpg (44.9 KB ) - added by Djing 2 years ago.
3. can't edit anymore once invalid item appear

Download all attachments as: .zip

Change History (10)

by Djing, 2 years ago

Attachment: first_all_valid.jpg added
  1. all valid items

by Djing, 2 years ago

2.it's ok to edit item to invalid

by Djing, 2 years ago

  1. can't edit anymore once invalid item appear

comment:1 by Djing, 2 years ago

Cc: Djing added

The exception is DoesNotExist, and it is thrown by the to_python method of django.forms.models.ModelChoiceField.

    def to_python(self, value):
        if value in self.empty_values:
            return None
        try:
            key = self.to_field_name or 'pk'
            if isinstance(value, self.queryset.model):
                value = getattr(value, key)
            value = self.queryset.get(**{key: value})
        except (ValueError, TypeError, self.queryset.model.DoesNotExist):
            raise ValidationError(self.error_messages['invalid_choice'], code='invalid_choice')
        return value

The ModelChoiceField and it's queryset come from the add_fields method of django.forms.models.BaseModelFormSet. This method builds field for pk according to the comment.

    # Omit the preceding part...
    if isinstance(pk, (ForeignKey, OneToOneField)):
        qs = pk.remote_field.model._default_manager.get_queryset()
    else:
        qs = self.model._default_manager.get_queryset()
    qs = qs.using(form.instance._state.db)
    if form._meta.widgets:
        widget = form._meta.widgets.get(self._pk_field.name, HiddenInput)
    else:
        widget = HiddenInput
    form.fields[self._pk_field.name] = ModelChoiceField(qs, initial=pk_value, required=False, widget=widget)
    # Omit the latter part...

The qs here use the default manager of Model which only shows valid items, so invalid item can't be found.

And I noticed that BaseModelFormSet has the correct queryset which shows all items when it is created by ModelAdmin.

comment:2 by Josh Michael Karamuth, 2 years ago

Came across the same problem and you're right.

qs = self.model._default_manager.get_queryset()

Should be

qs = self.get_queryset()

Thanks for debugging! Will you submit a PR for this?

in reply to:  2 comment:3 by Djing, 2 years ago

Replying to Josh Michael Karamuth:

Came across the same problem and you're right.

qs = self.model._default_manager.get_queryset()

Should be

qs = self.get_queryset()

Thanks for debugging! Will you submit a PR for this?

Yes.

comment:4 by Djing, 2 years ago

Owner: changed from nobody to Djing
Status: newassigned

comment:5 by David Sanders, 2 years ago

Please note the documentation warns about these situations where a default queryset hide/restricts the data it retrieves: https://docs.djangoproject.com/en/4.1/topics/db/managers/#default-managers

it’s a good idea to be careful in your choice of default manager in order to avoid a situation where overriding get_queryset() results in an inability to retrieve objects you’d like to work with.

It may be better to have the valid manager as the non-default and get the admin to use this instead.

in reply to:  2 comment:6 by Djing, 2 years ago

Replying to Josh Michael Karamuth:

This is my first time writing PR for django, and I follow the doc step by step. Now I'm having some problems with the test.
After modifying the code as mentioned before, there are 2 existing tests which located in model_formsets.tests.ModelFormsetTest failed.

    def test_prevent_change_outer_model_and_create_invalid_data(self):
        author = Author.objects.create(name="Charles")
        other_author = Author.objects.create(name="Walt")
        AuthorFormSet = modelformset_factory(Author, fields="__all__")
        data = {
            "form-TOTAL_FORMS": "2",
            "form-INITIAL_FORMS": "2",
            "form-MAX_NUM_FORMS": "",
            "form-0-id": str(author.id),
            "form-0-name": "Charles",
            "form-1-id": str(other_author.id),  # A model not in the formset's queryset.
            "form-1-name": "Changed name",
        }
        # This formset is only for Walt Whitman and shouldn't accept data for
        # other_author.
        formset = AuthorFormSet(
            data=data, queryset=Author.objects.filter(id__in=(author.id,))
        )
        self.assertTrue(formset.is_valid())
        formset.save()
        # The name of other_author shouldn't be changed and new models aren't
        # created.
        self.assertSequenceEqual(Author.objects.all(), [author, other_author])

    def test_edit_only_object_outside_of_queryset(self):
        charles = Author.objects.create(name="Charles Baudelaire")
        walt = Author.objects.create(name="Walt Whitman")
        data = {
            "form-TOTAL_FORMS": "1",
            "form-INITIAL_FORMS": "1",
            "form-0-id": walt.pk,
            "form-0-name": "Parth Patil",
        }
        AuthorFormSet = modelformset_factory(Author, fields="__all__", edit_only=True)
        formset = AuthorFormSet(data, queryset=Author.objects.filter(pk=charles.pk))
        self.assertIs(formset.is_valid(), True)
        formset.save()
        self.assertCountEqual(Author.objects.all(), [charles, walt])

They both give the formset a non-default queryset and pass data not in the queryset, and see if it just work for data in the queryset.(It seems just the opposite of mine).
So, only one of two situations can pass the test for self.assertTrue(formset.is_valid()), either theirs or mine.

I don't know how to deal with this situation.

Or just as David Sanders says:

It may be better to have the valid manager as the non-default and get the admin to use this instead

comment:7 by Carlton Gibson, 2 years ago

Resolution: duplicate
Status: assignedclosed

This is a duplicate of #33375: if you really need this pattern define a form class with the id field, using the desired queryset, so that BaseModelFormSet.add_fields() doesn't add the field with the default manager.

David is on track: you need to be extra careful with setting default managers that filter the QuerySet.

Last edited 2 years ago by Carlton Gibson (previous) (diff)
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