#29981: "Please correct the error below." (with no errors displayed) when
changing
an inline that has a one-to-one relation to the parent that uses to_field
-------------------------------+------------------------------------
Reporter: Bernie | Owner: nobody
Type: Bug | Status: new
Component: contrib.admin | Version: 2.1
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------+------------------------------------
Changes (by Tim Graham):
* stage: Unreviewed => Accepted
Old description:
> **Code sample:**
>
> models.py:
>
> {{{
> from django.db import models
>
> class Entry(models.Model):
> slug = models.SlugField(max_length=80, unique=True)
> title = models.CharField(max_length=255, blank=True, null=True)
>
> class Meta:
> verbose_name_plural = 'Entries'
>
> class EntryDetail(models.Model):
> entry = models.OneToOneField(
> Entry,
> to_field='slug',
> primary_key=True,
> on_delete=models.CASCADE
> )
> description = models.TextField(blank=True, null=True)
>
> class AnotherEntryDetail(models.Model):
> entry = models.OneToOneField(
> Entry,
> primary_key=True,
> on_delete=models.CASCADE
> )
> otherdescription = models.TextField(blank=True, null=True)
> }}}
>
> admin.py
>
> {{{
> from django.contrib import admin
> from .models import Entry, EntryDetail, AnotherEntryDetail
>
> class EntryDetailInline(admin.StackedInline):
> model = EntryDetail
>
> class AnotherEntryDetailInline(admin.StackedInline):
> model = AnotherEntryDetail
>
> @admin.register(Entry)
> class EntryAdmin(admin.ModelAdmin):
> inlines = [
> EntryDetailInline,
> AnotherEntryDetailInline
> ]
>
> def get_readonly_fields(self, request, obj=None):
> # Even with EntryDetail.entry_id ON UPDATE: CASCADE set on DB-
> level
> # changing Entry.slug through the admin-change-form with
> EntryDetail-inline fails.
> # Set slug readonly as workaround. Don't know if this is worth
> fixing.
> readonly_fields = super().get_readonly_fields(request, obj)
> if hasattr(obj, 'entrydetail') and 'slug' not in readonly_fields:
> readonly_fields += ('slug',)
> return readonly_fields
> }}}
>
> **Expected behavior:**
>
> In the admin:
> * add an Entry
> * fill slug and "Another entry detail" description
> * save
> * (change "Another entry detail" description)
> * **save**
>
> **Steps to reproduce the bug:**
>
> In the admin:
> * add an Entry
> * fill slug and "Entry detail" description
> * save
> * (change "Entry detail" description)
> * **save**
> * Error message in admin: "Please correct the error below."
>
> **Workaround:**
>
> in models.py replace
>
> {{{
> class EntryDetailInline(admin.StackedInline):
> model = EntryDetail
> }}}
>
> with:
>
> {{{
> from django.forms import BaseInlineFormSet
>
> class EntryDetailFormSet(BaseInlineFormSet):
> def add_fields(self, form, index):
> super().add_fields(form, index)
> related_name = self._pk_field.remote_field.related_name or
> self._pk_field.remote_field.name
> if hasattr(self.instance, related_name):
> form.fields[self._pk_field.name].to_field =
> self._pk_field.remote_field.field_name
>
> class EntryDetailInline(admin.StackedInline):
> model = EntryDetail
> formset = EntryDetailFormSet
> }}}
>
> ''Sorry for the confusing ticket-title, i couldn't come up with something
> better.''
New description:
**Code sample:**
models.py:
{{{
from django.db import models
class Entry(models.Model):
slug = models.SlugField(max_length=80, unique=True)
title = models.CharField(max_length=255, blank=True, null=True)
class EntryDetail(models.Model):
entry = models.OneToOneField(
Entry,
to_field='slug',
primary_key=True,
on_delete=models.CASCADE
)
description = models.TextField(blank=True, null=True)
}}}
admin.py
{{{
from django.contrib import admin
from .models import Entry, EntryDetail
class EntryDetailInline(admin.StackedInline):
model = EntryDetail
@admin.register(Entry)
class EntryAdmin(admin.ModelAdmin):
inlines = [EntryDetailInline]
def get_readonly_fields(self, request, obj=None):
# Even with EntryDetail.entry_id ON UPDATE: CASCADE set on DB-
level
# changing Entry.slug through the admin-change-form with
EntryDetail-inline fails.
# Set slug readonly as workaround. Don't know if this is worth
fixing.
readonly_fields = super().get_readonly_fields(request, obj)
if hasattr(obj, 'entrydetail') and 'slug' not in readonly_fields:
readonly_fields += ('slug',)
return readonly_fields
}}}
**Steps to reproduce the bug:**
In the admin:
* add an Entry
* fill slug, title, and "Entry detail" description
* save and continue editing
* change "Entry detail" description
* save
* Error message in admin: "Please correct the error below." (with no
errors listed). `formset[0].errors` is `[{'entry': ['The inline value did
not match the parent instance.']}]` which comes from
`InlineForeignKeyField` value is `aaa` and `orig` is `1`.
**Workaround:**
in models.py replace
{{{
class EntryDetailInline(admin.StackedInline):
model = EntryDetail
}}}
with:
{{{
from django.forms import BaseInlineFormSet
class EntryDetailFormSet(BaseInlineFormSet):
def add_fields(self, form, index):
super().add_fields(form, index)
related_name = self._pk_field.remote_field.related_name or
self._pk_field.remote_field.name
if hasattr(self.instance, related_name):
form.fields[self._pk_field.name].to_field =
self._pk_field.remote_field.field_name
class EntryDetailInline(admin.StackedInline):
model = EntryDetail
formset = EntryDetailFormSet
}}}
--
Comment:
I reproduced the issue on master
(78fc64578a8715b9812075bbebc829c1251c07fa). I removed
`AnotherEntryDetailInline` from the description as it doesn't seem
required to reproduce the issue.
--
Ticket URL: <https://code.djangoproject.com/ticket/29981#comment:1>
Django <https://code.djangoproject.com/>
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