Opened 14 years ago
Last modified 9 years ago
#15574 new Bug
IndexError: list index out of range caused by inline formsets
Reported by: | Paul Oswald | Owned by: | nobody |
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Component: | Forms | Version: | dev |
Severity: | Normal | Keywords: | inline formset |
Cc: | Patrick Kranzlmueller, Paul Oswald, Alan Justino da Silva, django@…, nik@…, joseph@…, cmawebsite@…, milos.urbanek@…, carsten.fuchs@… | Triage Stage: | Accepted |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
Note: I originally reported this as ticket #14642 but after discussion on the mailing list it has been decided that they are perhaps different issues. See http://groups.google.com/group/django-developers/browse_thread/thread/8c66461f1712dbb9
I was getting this error in my production system and I thought it was my forms. Turns out I could eliminate my forms as a source of the issue by using the admin. I've changed the summary to match. I reduced it down to this test case in Django 1.2.x:
models.py:
class Thingy(models.Model): description = models.CharField(max_length=256) class ThingyItem(models.Model): thingy = models.ForeignKey(Thingy) description = models.CharField(max_length=256)
admin.py:
class ThingyItemInline(admin.TabularInline): model = ThingyItem extra = 0 class ThingyAdmin(admin.ModelAdmin): inlines = [ThingyItemInline,] admin.site.register(Thingy, ThingyAdmin) admin.site.register(ThingyItem)
Now do the following:
- Create a new Thingy with several ThingyItems? in the admin and save it.
- Open the edit page.
- Open the edit page for the same thingy in a second browser window.
- Check the "Delete" button on the last ThingyItem? and save it in the second window.
- Now go back to the first form and save it
When I do this, I get:
Traceback (most recent call last): File "/Users/poswald/Projects/django/tests/regressiontests/admin_inlines/tests.py", line 211, in test_concurrent_editing_views response = self.client.post(reverse(edit_url, args=[self.thing.pk]), data[1]) File "/Users/poswald/Projects/django/django/test/client.py", line 455, in post response = super(Client, self).post(path, data=data, content_type=content_type, **extra) File "/Users/poswald/Projects/django/django/test/client.py", line 256, in post return self.request(**r) File "/Users/poswald/Projects/django/django/core/handlers/base.py", line 111, in get_response response = callback(request, *callback_args, **callback_kwargs) File "/Users/poswald/Projects/django/django/contrib/admin/options.py", line 308, in wrapper return self.admin_site.admin_view(view)(*args, **kwargs) File "/Users/poswald/Projects/django/django/utils/decorators.py", line 93, in _wrapped_view response = view_func(request, *args, **kwargs) File "/Users/poswald/Projects/django/django/views/decorators/cache.py", line 79, in _wrapped_view_func response = view_func(request, *args, **kwargs) File "/Users/poswald/Projects/django/django/contrib/admin/sites.py", line 190, in inner return view(request, *args, **kwargs) File "/Users/poswald/Projects/django/django/utils/decorators.py", line 28, in _wrapper return bound_func(*args, **kwargs) File "/Users/poswald/Projects/django/django/utils/decorators.py", line 93, in _wrapped_view response = view_func(request, *args, **kwargs) File "/Users/poswald/Projects/django/django/utils/decorators.py", line 24, in bound_func return func(self, *args2, **kwargs2) File "/Users/poswald/Projects/django/django/db/transaction.py", line 217, in inner res = func(*args, **kwargs) File "/Users/poswald/Projects/django/django/contrib/admin/options.py", line 978, in change_view queryset=inline.queryset(request)) File "/Users/poswald/Projects/django/django/forms/models.py", line 680, in __init__ queryset=qs) File "/Users/poswald/Projects/django/django/forms/models.py", line 416, in __init__ super(BaseModelFormSet, self).__init__(**defaults) File "/Users/poswald/Projects/django/django/forms/formsets.py", line 47, in __init__ self._construct_forms() File "/Users/poswald/Projects/django/django/forms/formsets.py", line 108, in _construct_forms self.forms.append(self._construct_form(i)) File "/Users/poswald/Projects/django/django/forms/models.py", line 689, in _construct_form form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs) File "/Users/poswald/Projects/django/django/forms/models.py", line 440, in _construct_form kwargs['instance'] = self.get_queryset()[i] File "/Users/poswald/Projects/django/django/db/models/query.py", line 173, in __getitem__ return self._result_cache[k] IndexError: list index out of range
It seems that the inline formset code is a bit brittle. An error is thrown when the data submitted in the management form is not in agreement with the state of the database. I'd like to make an automated test case for this but I'm not sure how to do that sequence of steps in the test client. If anyone can shed some light onto what the formset code is *supposed* to do in this situation it would be useful. I imagine the options are the second form overrides the first or something like a form validation error is raised that indicates the form is stale.
Attachments (3)
Change History (40)
by , 14 years ago
Attachment: | inline-formset-test.diff added |
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comment:1 by , 14 years ago
Triage Stage: | Unreviewed → Accepted |
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comment:2 by , 14 years ago
Type: | → Bug |
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comment:3 by , 14 years ago
Severity: | → Normal |
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comment:4 by , 13 years ago
Easy pickings: | unset |
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milestone: | → 1.4 |
Triage Stage: | Accepted → Design decision needed |
Setting to 'design decision needed'. I would appreciate if someone would explain what the formset code is supposed to do in this situation.
comment:6 by , 13 years ago
Cc: | added |
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UI/UX: | unset |
comment:7 by , 13 years ago
Cc: | added |
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comment:8 by , 13 years ago
Cc: | added |
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comment:9 by , 13 years ago
Cc: | added |
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Triage Stage: | Design decision needed → Unreviewed |
Version: | 1.3-beta → SVN |
I've been bitten by this in production, did some digging and have a possible solution.
This problem has several variants:
- If there are multiple relations and one of the relation other than the last one is deleted outside the current change view, you will get a "Please correct the error below" message... without showing where the error occured, because it's happening on a pk field, which is hidden.
- If there is only one relation or there are multiple relations but only the last
one is deleted, you'll get the
IndexError
- In addition, if you try to delete an already deleted relation, you'll get a
ValidatorError
, which isn't caught because it doesn't happen inside a form'sclean()
method, and will generate a 500 error.
Since the user has no way to correct/avoid this himself, I think the correct answer
to this problem is to simply ignore the forms in question. The worst thing that could
happen is that he'll lose any modification made to the concerned form(s), but that's
better than losing all his work on the page itself.
I'm attaching a patch that does exactly that, with a lot of tests to cover the different
variants. The heart of the problem lies in the fact that django BaseModelFormSet
tries to find
an instance for each form in the formset even if it doesn't make sense sometimes.
Because ModelForms
will consider a None
instance as a request for creation, the
best way to handle this, IMHO, is to bail early and remember how many forms are
problematic.
Edit: Note that my patch is built on top of attachment:inline-formset-test.diff and therefore probably makes it obsolete.
by , 13 years ago
Attachment: | inline-formsets-15574.diff added |
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comment:10 by , 13 years ago
Has patch: | set |
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comment:11 by , 13 years ago
I don't think it is a good idea to just throw the deleted model's form data out and save the rest as if nothing went wrong. A concurrent delete should lead to validation error of "It seems B was deleted concurrently, verify changes and try again.". (Or just "Concurrent modification. Please verify changes and save again").
comment:12 by , 13 years ago
The problem is, AFAIK django doesn't have any mechanism to deal with this kind of errors. Showing an error to the user is possible, but he won't be able to correct the problem, since the simple presence of the deleted inline in data will trigger this issue. He has no way of forcing django to ignore this form (which he may or may not have touched at all in the first place)
comment:13 by , 13 years ago
Triage Stage: | Unreviewed → Design decision needed |
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So, lets add some mechanism for that :)
I really think that skipping part of the submitted data and claiming that everything went well is plain evil. Even a 500 error is better than doing a partial save without any notification.
Is it possible to just raise a ValidationError("Concurrent Modification. Verify changes.")
, show the remaining forms for the user (remove the deleted ones), and let the user decide what to do. That is, make it explicit to the user what is saved and what is not saved.
It would of course be better to show the deleted forms and give the user the ability to resurrect them, but that will be more complicated to implement.
I am putting this back to DDN triage stage, as it seems pretty clear some design decision is needed.
comment:15 by , 12 years ago
visik7: my patch was made for trunk, but it shouldn't be hard to adapt to 1.3.1.
Note to those who want to use my patch as a base: there is a case that doesn't work: if the user, when using the django admin with the patch, submits a form a deleted relation but also containing another error, he'll get the form again to get a chance to correct the error, but the formset management form will output TOTAL_FORMS/INITIAL_FORMS inconsistent with the number of forms, and therefore the user won't be able to submit the form.
comment:16 by , 12 years ago
I am getting the following: "list index out of range" exception when updating object with inline formset
My code is as follows:
class ProjectUpdateView(UpdateView): form_class = ProjectForm template_name = 'projects/project_create.html' success_url = reverse_lazy('projects-list') def get_object(self, queryset=None): obj = Project.objects.get(id=self.kwargs['pk']) return obj def get_context_data(self, **kwargs): context = super(ProjectUpdateView, self).get_context_data(**kwargs) project = Project.objects.get(id=self.kwargs['pk']) if self.request.POST: context['reward_formset'] = ProjectRewardFormSet(self.request.POST, self.request.FILES, instance=project) else: context['reward_formset'] = ProjectRewardFormSet(instance=project) return context def form_valid(self, form): context = self.get_context_data() reward_formset = context['reward_formset'] if reward_formset.is_valid(): self.object = form.save(commit=False) self.object.owner = self.request.user self.object.save() reward_formset.instance = self.object reward_formset.save() return HttpResponseRedirect(self.get_success_url()) else: return self.render_to_response(self.get_context_data(form=form))
And the traceback as follows:
/home/lk/.venv/repo/lib/python2.7/site-packages/django/core/handlers/base.py in get_response 111. response = callback(request, *callback_args, **callback_kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/contrib/auth/decorators.py in _wrapped_view 20. return view_func(request, *args, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/views/generic/base.py in view 48. return self.dispatch(request, *args, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/views/generic/base.py in dispatch 69. return handler(request, *args, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/views/generic/edit.py in post 172. return super(BaseCreateView, self).post(request, *args, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/views/generic/edit.py in post 138. return self.form_valid(form) ... ▶ Local vars /home/lk/.venv/repo/repo/../repo/projects/views.py in form_valid 22. context = self.get_context_data() ... ▶ Local vars /home/lk/.venv/repo/repo/../repo/projects/views.py in get_context_data 39. context['reward_formset'] = ProjectRewardFormSet(self.request.POST) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/models.py in __init__ 697. queryset=qs, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/models.py in __init__ 424. super(BaseModelFormSet, self).__init__(**defaults) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/formsets.py in __init__ 50. self._construct_forms() ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/formsets.py in _construct_forms 115. self.forms.append(self._construct_form(i)) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/models.py in _construct_form 706. form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs) ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/forms/models.py in _construct_form 451. kwargs['instance'] = self.get_queryset()[i] ... ▶ Local vars /home/lk/.venv/repo/lib/python2.7/site-packages/django/db/models/query.py in __getitem__ 190. return self._result_cache[k] ... ▶ Local vars
I have read the following issue but I am not able to figure out what I should change exactly in my code! I have been facing since exception since days and I am really stuck! I would appreciate a quick and detailed reply! Many thanks in advance!
comment:17 by , 12 years ago
The initial code you include doesn't match the code in your traceback. Traceback includes:
▶ Local vars /home/lk/.venv/repo/repo/../repo/projects/views.py in get_context_data 39. context['reward_formset'] = ProjectRewardFormSet(self.request.POST) ...
which is not passing an instance in with the post data. That's likely a problem.
comment:18 by , 12 years ago
That is so weird!!! I just noticed that it always goes to the CreateView not the UpdateView even though I am redirecting the url to the UpdateView
class ProjectCreateView(CreateView): form_class = ProjectForm template_name = 'projects/project_create.html' success_url = reverse_lazy('projects-list') def form_valid(self, form): context = self.get_context_data() reward_formset = context['reward_formset'] if reward_formset.is_valid(): self.object = form.save(commit=False) self.object.owner = self.request.user self.object.save() reward_formset.instance = self.object reward_formset.save() action.send(self.request.user, verb='created', target=self.object) return HttpResponseRedirect(self.get_success_url()) else: return self.render_to_response(self.get_context_data(form=form)) def get_context_data(self, **kwargs): context = super(ProjectCreateView, self).get_context_data(**kwargs) if self.request.POST: context['reward_formset'] = ProjectRewardFormSet(self.request.POST) else: context['reward_formset'] = ProjectRewardFormSet() return context class ProjectUpdateView(UpdateView): form_class = ProjectForm template_name = 'projects/project_create.html' success_url = reverse_lazy('projects-list') def form_valid(self, form): context = self.get_context_data() reward_formset = context['reward_formset'] if reward_formset.is_valid(): self.object = form.save(commit=False) self.object.owner = self.request.user self.object.save() reward_formset.instance = self.object reward_formset.save() return HttpResponseRedirect(self.get_success_url()) else: return self.render_to_response(self.get_context_data(form=form)) def get_object(self, queryset=None): obj = Project.objects.get(id=self.kwargs['pk']) return obj def get_context_data(self, **kwargs): context = super(ProjectUpdateView, self).get_context_data(**kwargs) project = Project.objects.get(id=self.kwargs['pk']) if self.request.POST: context['reward_formset'] = ProjectRewardFormSet(self.request.POST, self.request.FILES, instance=project) else: context['reward_formset'] = ProjectRewardFormSet(instance=project) return context
Have anyone faced this before?
comment:19 by , 12 years ago
You'll likely have better luck getting a response posting on django-users or #django IRC, this is now veering pretty far off the bug that is this ticket.
comment:20 by , 12 years ago
Just ran into this issue myself, and reported in #19408. I get the "IndexError" if I was to simultaneously delete the last item in a formset, but get an uncaught ValidationError exception - uncaught, in that it returns a 500 code rather than a redbox in the form, if I simultaneously delete middle items.
I agree that there's no real good solution, here.
Clearly if there's simultaneous deletes, then "WELL, NOT A PROBLEM". However, if one form attempts a delete, and the other an edit, then it's not so clear. The best solution would be to come up with some kind of validation error for the subsequent attempt, but what, exactly, to display is the question. However, given that there is currently NO checking for simultaneous edits. (the 2nd submitted edits will override the first), I think its safe to say that we don't have to be "Perfect" here... if someone wants perfection, then they're going to have to arrange some kind of funky locking themselves, and Django should be relied on to just "do something that makes sense".
So, in that vein, here's my proposal:
- No matter what, Django should cope with the case that a row disappears, so the "IndexError" should never happen.
- A delete followed by a re-delete on the same form results in a delete with no warning.
- A delete followed by an edit results in a validation error for the second action, the edit. However, since the row is _gone_, the error is an error on the form set saying that "<Object x> has been recently deleted, and your edits have been discarded". Simply re-submitting the form will now work.
- An edit followed by a delete (if this can even be detected) results in a validation error on the form being deleted. The form shows the post-edit values. The message is "<Object x> has recently been changed. You may attempt to re-delete it."
- An edit followed by an edit (again, if this is even detected) will just save the new edits. Given the "absolute best option" would be to somehow show the newly-changed values while keeping the user's edits so he can validate it is a very tall order, I would just fall back on saving the 2nd set of edits, and making this behaviour well documented.
comment:21 by , 12 years ago
Has patch: | unset |
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Hi everyone,
I got the same problem with Django 1.1. But, the real problem is my app'd worked well before I added 3 foreignkey field to the model. My code as follow:
models.py:
class PtcEvent(models.Model): name = models.CharField(max_length=50) desc = models.TextField(verbose_name='description') grades = models.ManyToManyField(Grade) view_start = models.DateTimeField(default=NOW) view_end = models.DateTimeField(default=NOW + timedelta(days=30)) edit_start = models.DateTimeField(default=NOW) edit_end = models.DateTimeField(default=NOW + timedelta(days=25)) active = models.BooleanField(default=True) granularity = models.SmallIntegerField(default=30) # buffer minutes will simply display the booking time length shorter: granularity - buffer_minutes buffer_minutes = models.SmallIntegerField(default=5) # the new 3 fields default_notification_mail_body = models.ForeignKey(EmailTemplate, null=True, \ related_name='notification_mail_template') default_teacher_confirmation_mail_body = models.ForeignKey(EmailTemplate, null=True, \ related_name='teacher_confirmation_mail_template') default_parent_confirmation_mail_body = models.ForeignKey(EmailTemplate, null=True, \ related_name='parent_confirmation_mail_template') def __unicode__(self): return u'%s (%s)' % (self.name, self.view_start.strftime(DATE_FORMAT)) def get_status(self): now = datetime.now() if self.view_start <= now and now < self.view_end: if self.edit_start <= now and now < self.edit_end: return EVENT_LIVE else: return EVENT_VIEW return EVENT_CLOSED def get_status_text(self): return EVENT_STATUS_TEXT[self.get_status()] class Meta: ordering = ['-view_start','name'] verbose_name = "PTC Event" class PtcPeriod(models.Model): start_date = models.DateField(default=date.today() + timedelta(days=30)) start_time = models.TimeField(default=time(8,0)) end_time = models.TimeField(default=time(12,0)) teacher_blocks = models.SmallIntegerField(default=1) ptc_event = models.ForeignKey(PtcEvent) def __unicode__(self): return u'%s [%s, %s-%s]' % (self.ptc_event.name, self.start_date.strftime(DATE_FORMAT), self.start_time.strftime(TIME_FORMAT), self.end_time.strftime(TIME_FORMAT)) def start(self): return datetime.combine(self.start_date, self.start_time) def end(self): return datetime.combine(self.start_date, self.end_time) def slot_list(self): result = [] step = timedelta(minutes=self.ptc_event.granularity) start_time = self.start() end_time = self.end() cur_time = start_time while (cur_time < end_time): result.append(cur_time) cur_time = cur_time + step return result def slot_list_text(self): result = [ v.strftime(DATETIME_FORMAT) for v in self.slot_list()] return result class Meta: ordering = ['-start_date'] verbose_name = "PTC Period"
forms.py:
class PtcEventForm(ModelForm): # view_start and edit_start = datetime when the ptcevent is created view_start = DateTimeField(widget=SplitSelectDateTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True)) view_end = DateTimeField(widget=SplitSelectDateTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True)) edit_start = DateTimeField(widget=SplitSelectDateTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True)) edit_end = DateTimeField(widget=SplitSelectDateTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True)) grades = ModelMultipleChoiceField(widget=ColumnCheckboxSelectMultiple(), required=True, queryset=Grade.objects.all()) class Meta: model = PtcEvent exclude = ('active', 'granularity', 'buffer_minutes',) PtcPeriodFormSetBase_edit = inlineformset_factory(PtcEvent, PtcPeriod, extra=0, max_num=10, can_delete=True) class PtcPeriodFormSet_edit(PtcPeriodFormSetBase_edit): def add_fields(self, form, index): super(PtcPeriodFormSet_edit, self).add_fields(form, index) form.fields['start_date'].widget = SelectDateWidget() form.fields['start_time'].widget = SelectTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True) form.fields['end_time'].widget = SelectTimeWidget(hour_step=1, \ minute_step=15, second_step=60, twelve_hr=True) form.fields['teacher_blocks'].widget.attrs['size'] = 2
views.py:
def edit_ptc_event(request, ptcevent_id): current_selected_event_id = get_current_selected_event_id(request) all_ptc_events = get_all_active_events() staff = request.user page_title = "Edit PTC Event" if request.method == 'POST': action = request.POST.get('action') ptc_event_form = PtcEventForm(request.POST, request.FILES) if ptc_event_form.is_valid(): if action == u'save': ptc_event = ptc_event_form.save(commit=False) log_info("ptc event edit %s" % str(ptc_event)) ptc_period_formset = PtcPeriodFormSet_edit(request.POST, request.FILES, instance=ptc_event) log_info("ptc_period_formset %s" % str(ptc_period_formset)) if ptc_period_formset.is_valid(): ptc_event.save() ptc_event_form.save_m2m() # important! ptc_period_formset.save() return redirect('conferences.staff.views.manage_ptc_events') else: ptc_period_formset = PtcPeriodFormSet_edit(request.POST, request.FILES) else: ptc_event = PtcEvent.objects.get(pk=ptcevent_id) ptc_event_form = PtcEventForm(instance=ptc_event) ptc_period_formset = PtcPeriodFormSet_edit(instance=ptc_event) return render_to_response('staff/add_new_ptc_event.html', locals(), context_instance=RequestContext(request))
add_new_ptc_event.html template:
{% extends "staff/base.html" %} {% block head_extra %} <script src="/site_media/js/jquery.min.js"></script> <script src="/site_media/js/addformtoformset.js"></script> {% endblock %} {% block actionarea %} <br> <table class="main-title" width="100%"> <tr> <td><h1>{{ page_title }}</h1></td> <td class="main-button"><a href="/staff/ptcevents/all/"><button class="mini button gray">Back</button></a></td> </tr> </table> <br> {% if ptc_event_form %} <span class="noted">(*) All fields are required!</span> <form method="post" action="" accept-charset="utf-8"> <table id="add-ptc-event" class="table-wrapper vertical" width="99%" border="0"> <tr> <th>Name</th> <td> <span class="error">{{ ptc_event_form.name.errors }}</span> {{ ptc_event_form.name }} </td> </tr> <tr> <th>Description</th> <td> <span class="error">{{ ptc_event_form.desc.errors }}</span> {{ ptc_event_form.desc }} </td> </tr> <tr> <th>View start</th> <td> <span class="error">{{ ptc_event_form.view_start.errors }}</span> {{ ptc_event_form.view_start }} </td> </tr> <tr> <th>View end</th> <td> <span class="error">{{ ptc_event_form.view_end.errors }}</span> {{ ptc_event_form.view_end }} </td> </tr> <tr> <th>Edit start</th> <td> <span class="error">{{ ptc_event_form.edit_start.errors }}</span> {{ ptc_event_form.edit_start }} </td> </tr> <tr> <th>Edit end</th> <td> <span class="error">{{ ptc_event_form.edit_end.errors }}</span> {{ ptc_event_form.edit_end }} </td> </tr> <tr> <th>Grades</th> <td> <span class="error">{{ ptc_event_form.grades.errors }}</span> {{ ptc_event_form.grades }} </td> </tr> <tr> <th>Notification mail template</th> <td> <span class="error">{{ ptc_event_form.default_notification_mail_body.errors }}</span> {{ ptc_event_form.default_notification_mail_body }} </td> </tr> <tr> <th>Teacher confirmation mail template</th> <td> <span class="error">{{ ptc_event_form.default_teacher_confirmation_mail_body.errors }}</span> {{ ptc_event_form.default_teacher_confirmation_mail_body }} </td> </tr> <tr> <th>Parent confirmation mail template</th> <td> <span class="error">{{ ptc_event_form.default_parent_confirmation_mail_body.errors }}</span> {{ ptc_event_form.default_parent_confirmation_mail_body }} </td> </tr> <!-- Ptc Period Formset--> <tr id="vertical-nohover"> <td colspan="2"> <table class="table-wrapper" id="add-ptc-period-table" width="99%"> <tr><td colspan="5" class="radio title">PTC Periods</td></tr> <tr> <td class="column">Start date</td> <td class="column">Start time</td> <td class="column">End time</td> <td class="column">Teacher blocks</td> <td class="column">Action</td> </tr> {{ ptc_period_formset.management_form }} {% for ptc_period_form in ptc_period_formset.forms %} <tr class="item"> <td class="radio"> {{ ptc_period_form.id }} {{ ptc_period_form.start_date }} </td> <td class="radio"> {{ ptc_period_form.start_time }} </td> <td class="radio"> {{ ptc_period_form.end_time }} </td> <td class="radio textfield"> {{ ptc_period_form.teacher_blocks }} </td> <td><a class="delete mini button gray radio" href="#">Delete</a></td> {{ ptc_period_form.ptc_event.as_hidden }} </tr> {% endfor %} <tr> <td colspan="5" class="radio" id="addbtn" style="padding-right: 4px;"><a id="add" href="#" class="mini button blue">Add</a></td> </tr> </table> </td> </tr> <tr> <th>Action</th> <td> <button type="reset" value="Reset" class="medium button gray">Reset</button></a> <button type="submit" name="action" value="save" class="medium button blue">Save</button> </td> </tr> </table> <br> </form> {% else %} <p>There's something wrong with the Database! Please contact the System Administrator for Support!</p> {% endif %} <br> <br> {% endblock %}
comment:22 by , 12 years ago
Triage Stage: | Design decision needed → Accepted |
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This is obviously a bug, moving back to accepted.
comment:23 by , 11 years ago
Is there any workaround for this issue?
Maybe a way to disable caching for formsets.
I do have more formset-caching problems aswell:
When a formset is saved the old (and now outdated)
formset is often served instead if a fresh.
comment:24 by , 11 years ago
Cc: | added |
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comment:25 by , 11 years ago
Cc: | added |
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follow-up: 27 comment:26 by , 11 years ago
One workaround is to override your ModelAdmin's change_view
to catch an IndexError
, clean the nonexistent entries from request.POST
and rerun super's change_view
. When cleaning, make sure to reduce 'foo_set-TOTAL_FORMS'
etc. values.
This ticket's been open for three years, by the way.
comment:27 by , 11 years ago
Replying to naktinis@…:
One workaround is to override your ModelAdmin's
change_view
to catch anIndexError
, clean the nonexistent entries fromrequest.POST
and rerun super'schange_view
. When cleaning, make sure to reduce'foo_set-TOTAL_FORMS'
etc. values.
This ticket's been open for three years, by the way.
could you be so kind and post a snippet of this?
comment:28 by , 11 years ago
Tried:
def change_view(self, request, object_id, form_url='', extra_context=None): try: return super(MyModelAdmin, self).change_view(request, object_id, form_url, extra_context) except IndexError: for key, value in request.POST.items(): if key.startswith('templatepage'): request.POST.pop(key) return super(TemplateAdmin, self).change_view(request, object_id, form_url, extra_context)
but is gives me ValidationError: ManagementForm data is missing or has been tampered with
comment:29 by , 11 years ago
I think some of the errors in this ticket (for example double delete) are now fixed in master. See efb0100ee67931329f17bc9988ecd5f0619cea14.
I am not sure what happens in edit deleted case.
follow-up: 33 comment:30 by , 11 years ago
Well, for those stuck in 1.4 in the meantime this is the workaround I'm using:
the problem with my previous snippet was that I was removing too much, I considered using a regex but that would be overkill.
in my case I'm removing everything so now I'm simply doing as below instead of a loop:
request.POST['templatepage_set-TOTAL_FORMS'] = '0'
in any case, is this fix in 1.6?
comment:33 by , 10 years ago
Replying to Avraham Seror <tovmeod@…>:
Well, for those stuck in 1.4 in the meantime this is the workaround I'm using:
the problem with my previous snippet was that I was removing too much, I considered using a regex but that would be overkill.
in my case I'm removing everything so now I'm simply doing as below instead of a loop:
request.POSTtemplatepage_set-TOTAL_FORMS = '0'
in any case, is this fix in 1.6?
For anyone who's still wondering; the above mentioned fix in master seems to have been included in 1.7.
comment:34 by , 10 years ago
Cc: | added |
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comment:35 by , 10 years ago
Cc: | added |
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comment:36 by , 10 years ago
This bug is very annoying in production.
Moreover from my observations under Django 1.4, which I'm running, the patch in https://github.com/django/django/commit/efb0100ee67931329f17bc9988ecd5f0619cea14 does not solve anything.
The IndexError does not happen with that patch, but ValidationError due the the invalid pkey is thrown instead in the form and attempt to re-submit the form yields "MultiValueKeyDictError" exception due to the missing pkey ID data.
My solution is to detect the case, when the form object was deleted, remove its form data from the formset and to throw a ValidationError at the formset level.
The user can then check the form - which is already missing the deleted object - and re-submit it.
Patch against Django 1.4 attached. Hope it helps.
by , 10 years ago
Attachment: | inline_formsets_15574_v2.diff added |
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comment:37 by , 9 years ago
Cc: | added |
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Discussion in #11313 (
list_editable
is also implemented with model formsets) and the report of the OP about observing the same problems with custom non-admin formsets seem to point this multiple simultaneous edition safety problem is a limitation of Django model formsets.