Develop Reference

django / filter the fields of a form and have the error 'int' object has no attribute '_meta'

I use django-cities-light for a travel website and I would like to filter the cities in the fields ville_de_depart and ville_destination in the newBookingForm by trip.depart and trip.destination.
I tried to pass the trip object in the instance of newBookingForm. I override the __init__ and I took the value of the depart and destination, I succeeded in filtering the fields but I could no longer save the newBooking, the view redirect to the alltrip page with no error but no new booking is added to the database.
I tried to replace the trip by the slug which is the same value as the id and it shows me this error
'int' object has no attribute '_meta'
models.py
class trip(models.Model):
depart = models.ForeignKey(default='',to=Country,on_delete=models.CASCADE,related_name='depart')
destination = models.ForeignKey(default='',to=Country,on_delete=models.CASCADE)
date_de_depart = models.DateField(default='')
prix_kg = models.PositiveIntegerField(default='')
collecte = models.BooleanField(default=False,null=False,help_text='' )
creation_date = models.DateTimeField(auto_now=True)
author = models.ForeignKey(to=settings.AUTH_USER_MODEL,on_delete=models.CASCADE,default='')
slug = models.SlugField(max_length=100, default='' )
#jouter slug
def save(self, *args , **kwargs):
super(trip, self).save(*args , **kwargs)
if not self.slug:
self.slug = self.id
self.save()
def __str__(self):
return f'{self.id} {self.author} '
class Booking(models.Model):
trip = models.ForeignKey(trip,on_delete=models.CASCADE, default='',)
author = models.ForeignKey(to=settings.AUTH_USER_MODEL,on_delete=models.CASCADE,default='')
creation_date = models.DateTimeField(auto_now=True)
ville_de_depart = models.ForeignKey(City,on_delete=models.CASCADE,default='')
slug = models.SlugField(max_length=100, default='' )
# ville_depart = models.ForeignKey(default='',to=City,on_delete=models.CASCADE,related_name='ville_dep')
sender_phone = PhoneNumberField(blank=True)
receiver_phone = PhoneNumberField()
ville_destination = models.ForeignKey(default='',to=City,on_delete=models.CASCADE,related_name='ville_dest')
#jouter slug
def save(self, *args , **kwargs):
super(Booking, self).save(*args , **kwargs)
if not self.slug:
self.slug = self.id
self.save()
def __str__(self):
return str(self.trip.author)
views.py
def detailsTrip(request, slug):
trip = get_object_or_404(models.trip,slug=slug)
auth = trip.author
bookingForm = newBookingForm(instance=slug)
context = {'trip': trip, 'auth': auth, 'form': bookingForm}
if request.method == 'POST':
form = newBookingForm(request.POST , instance=slug )
if request.user.is_authenticated:
if form.is_valid():
trip = get_object_or_404(models.trip,slug=slug)
Booking = form.save(commit=False)
Booking.trip_id= trip.id
Booking.author_id = request.user.id
Booking = form.save()
return redirect('/alltrips')
else:
trip = get_object_or_404(models.trip,slug=slug)
auth = trip.author
bookingForm = newBookingForm()
context = {'trip': trip, 'auth': auth, 'form': bookingForm}
return render(request, 'detailstrip.html', context)
else:
return render (request, 'notFound.html')
return render(request,'detailstrip.html', context , )
forms.py
class newBookingForm(forms.ModelForm,):
def __init__(self,*args,**kwargs):
# capture the instance : Slug
slug = kwargs.get('instance')
# capture current trip
Trip = get_object_or_404(trip, id=slug)
# Filter cities field by the instance : trip.depart / trip.destination
super(newBookingForm, self).__init__(*args,**kwargs)
self.fields['ville_de_depart'].queryset = City.objects.filter(country_id=Trip.depart)
self.fields['ville_destination'].queryset = City.objects.filter(country_id=Trip.destination)
class Meta:
model = Booking
fields = ['ville_de_depart','ville_destination']
exclude = ['sender_phone','receiver_phone']

solution
#view.py
def detailsTrip(request, slug):
trip = get_object_or_404(models.trip,slug=slug)
auth = trip.author
#add the trip to the form
bookingForm = newBookingForm(trip=trip)
context = {'trip': trip, 'auth': auth, 'form': bookingForm}
if request.method == 'POST':
#add the object trip to the form here too
form = newBookingForm(trip,request.POST )
if request.user.is_authenticated:
if form.is_valid():
trip = get_object_or_404(models.trip,slug=slug)
Booking = form.save(commit=False)
Booking.trip_id= trip.id
Booking.author_id = request.user.id
Booking = form.save()
return redirect('/alltrips')
else:
trip = get_object_or_404(models.trip,slug=slug)
auth = trip.author
bookingForm = newBookingForm()
context = {'trip': trip, 'auth': auth, 'form': bookingForm}
return render(request, 'detailstrip.html', context)
else:
return render (request, 'notFound.html')
return render(request,'detailstrip.html', context , )
form.py
class newBookingForm(forms.ModelForm,):
class Meta:
model = Booking
fields = ['ville_de_depart','ville_destination']
exclude = ['sender_phone','receiver_phone']
def __init__(self,trip,*args,**kwargs):
# Filter cities field by trip.depart / trip.destination
super(newBookingForm, self).__init__(*args,**kwargs)
self.fields['ville_de_depart'].queryset = City.objects.filter(country=trip.depart)
self.fields['ville_destination'].queryset = City.objects.filter(country=trip.destination)

As long as you use many-to-many fields, you need to call form.save_m2m() after saving the model instance. or you can just call form.save() without commit=False keyword argument.
Here are some quotes from Django documentation:
This save() method accepts an optional commit keyword argument, which accepts either True or False. If you call save() with commit=False, then it will return an object that hasn’t yet been saved to the database.
Another side effect of using commit=False is seen when your model has a many-to-many relation with another model. If your model has a many-to-many relation and you specify commit=False when you save a form, Django cannot immediately save the form data for the many-to-many relation.
read this documentation about the save method

Post method is not working in updateview django

I have a update view in django project. I need to override the post method because I am using multiple modelform. I have already override createview. And it is working fine.
views.py:
class EmployeeUpdateView(LoginRequiredMixin, UpdateView):
"""
Update a created a employee
"""
login_url = '/authentication/login/'
template_name = 'employee/employee_update_form.html'
form_class = EmployeeAddModelForm
work_form_class = WorkExperienceForm
education_form_class = EducationForm
queryset = Employee.objects.all()
#success_url = reverse_lazy('employee:employee-list')
def get(self, request, *args, **kwargs):
id_ = self.kwargs.get("id")
employee_id = Employee.objects.get(id=id_)
work_info = WorkExperience.objects.get(employee=employee_id)
education_info = Education.objects.get(employee=employee_id)
return render(request, self.template_name, {
'form': self.form_class(instance=employee_id),
'work_form': self.work_form_class(instance=work_info),
'education_form': self.education_form_class(instance=education_info)
}
)
def post(self, request, *args, **kwargs):
form = self.form_class(request.POST)
work_form = self.work_form_class(request.POST, prefix='work_form')
education_form = self.education_form_class(request.POST, prefix='education_form')
# Check form validation
if form.is_valid() and work_form.is_valid() and education_form.is_valid():
instance = form.save()
work = work_form.save(commit=False)
education = education_form.save(commit=False)
work.employee = instance
education.employee = instance
work.update()
education.update()
return redirect('employee:employee-list')
return render(request, self.template_name, {
'form': form,
'work_form': work_form,
'education_form': education_form
}
)
When I press update button of my form, error is giving showwing "This field already exist". It means when i update the form, it is posting data as a new form not as a update form.
I think my post method is not working. Where is the error in my post method?

You can write your own view like this instead of sub classing the generic view. Since you are working with more than one model here so it will be easy for you to write your own view.
class EmployeeUpdateView(LoginRequiredMixin, View):
.......
def post(self, request, *args, **kwargs):
id_ = self.kwargs.get("id")
employee_id = Employee.objects.get(id=id_)
work_info = WorkExperience.objects.get(employee=employee_id)
education_info = Education.objects.get(employee=employee_id)
form = self.form_class(request.POST, instance=employee_id)
work_form = self.work_form_class(request.POST, prefix='work_form', instance=work_info)
education_form = self.education_form_class(request.POST, prefix='education_form',instance=education_info)
# Check form validation
if form.is_valid() and work_form.is_valid() and education_form.is_valid():
instance = form.save()
work = work_form.save(commit=False)
education = education_form.save(commit=False)
work.employee = instance
education.employee = instance
work.save()
education.save()
return redirect('employee:employee-list')
return render(request, self.template_name, {
'form': form,
'work_form': work_form,
'education_form': education_form
}
)

data is not saving in model using django formset

i am using django formset to save multiple form at a time.but data is not saving in my database.I am using class based views.This is the model where i want to save my data.
Model
class Period(AbstractBaseModel):
validators = [ScreenMethodValidator, ChainIntegrityValidator]
chain = models.ForeignKey(
'customers.Chain',
help_text=_('chain to which period belongs to'),
verbose_name=_('chain')
)
start_date = models.DateTimeField(
default=datetime.datetime.now,
help_text=_('Starting date of a period'),
verbose_name=_('start date')
)
end_date = models.DateTimeField(
default=datetime.datetime(1970, 01, 01),
help_text=_('Ending date of a period'),
verbose_name=_('end date')
)
year = models.IntegerField(
default=0,
help_text=_('Financial year'),
verbose_name=_('year'),
null=True,blank=True
)
description = models.TextField(
help_text=_('Description of a period'),
verbose_name=_('description'),
null=True,blank=True
)
class Meta:
app_label = 'accounting'
and View
class PeriodCreate(RequestPassingFormViewMixin, WammuCreateView):
model = Chain
template_name = 'dashboard/period_form.html'
form_class = ChainForm
def get_object(self):
chain = Chain.objects.get(pk=self.kwargs['chain_pk'])
return chain
def get_success_url(self):
return reverse('dashboard_period_list', kwargs={'chain_pk': self.object.chain.id, })
def get_context_data(self, **kwargs):
context = super(PeriodCreate, self).get_context_data(**kwargs)
return context
def get_form_kwargs(self, *args, **kwargs):
kwargs = super(PeriodCreate, self).get_form_kwargs(*args, **kwargs)
chain = get_object_or_404(Chain, pk=self.kwargs['chain_pk'])
period = Period(chain=chain)
kwargs['instance'] = period
return kwargs
def get(self, request, *args, **kwargs):
self.object = None
form_class = self.get_form_class()
form = self.get_form(form_class)
PeriodInlineFormSet = inlineformset_factory(Chain, Period,
form=PeriodInlineForm,
can_delete=True,
extra=12)
PeriodInlineFormSet.form = staticmethod(curry(PeriodInlineForm, request=request, chain=self.object))
period_formset = PeriodInlineFormSet()
return self.render_to_response(
self.get_context_data(form=form,
period_inline_formset=period_formset))
def post(self, request, *args, **kwargs):
self.object = Chain()
form = self.get_form(self.form_class)
PeriodInlineFormSet = inlineformset_factory(Chain, Period,
form=PeriodInlineForm,
can_delete=True,
extra=12)
PeriodInlineFormSet.form = staticmethod(curry(PeriodInlineForm))
if form.is_valid():
self.object = form.save(commit=False)
period_formset = PeriodInlineFormSet(request.POST, instance=self.object)
if period_formset.is_valid():
self.object.save()
period_formset.save()
return super(PeriodCreate, self).form_valid(form)
else:
return self.render_to_response(
context=self.get_context_data(form=form, period_inline_formset=period_formset))
else:
period_formset = PeriodInlineFormSet(request.POST,instance=self.object)
return self.render_to_response(
context=self.get_context_data(form=form, period_inline_formset=period_formset))
and use the following link to see my other code related to this issue where i have tried to use django formset and faced an argument error which has been solved
but now data is not saving in data base when i am trying to post data.surely the error is occurring in my post method,but as i am not used to work with django formset,i can't figure it out after a long findings.
django __init__ method causing argument error

Django: __init__() got an unexpected keyword argument 'instance'

I have the following form:
class locationForm(forms.Form):
existing_regions= forms.ModelChoiceField(queryset=Region.objects.none(), label="Region Name", required=False)
region_name = forms.CharField()
location_name = forms.CharField()
street_address = forms.CharField()
city = forms.CharField()
zip_code = forms.CharField()
And the following update view for this form:
class UpdateLocation(View):
template_name = "dash/location_update_form.html"
def get(self, request, *args, **kwargs):
loc = kwargs['name']
try:
location = Location.objects.get(name=loc)
form = locationForm(instance=location)
return render(request, self.template_name, {'form': form,'location': location})
except (ValueError, ObjectDoesNotExist):
return redirect(reverse('geofence_manager'))
def post(self, request, *args, **kwargs):
loc = self.kwargs['name']
try:
location = Location.objects.get(name=loc)
form = locationForm (request.POST, instance=location)
if form.is_valid():
form.save()
else:
form = locationForm(request.POST, instance=location)
return render(request, self.template_name, {'location': location, 'form': form})
except (ValueError, ObjextDoesNotExist):
return redirect(reverse('location_manager'))
return redirect(reverse('location_manager'))
I am receiving an error in regards to 'instance' key word argument being used. I believe this has something to do with me not using a Modelform(I could be wrong). But I do not want to use a Modelform to construct my form, so is there a way I can get around this?

class locationForm(ModelForm):
class Meta:
model = Location
fields = '__all__'
in your view:
...
locationForm.base_fields['existing_regions'] = forms.ModelChoiceField(queryset= ...)
form = locationForm()

django admin form empty after POST

I am having trouble posting data in an admin form. Some fields get empty after clicking the save button, others not (the inlines are keeping their data). See the images for a better explanation of the problem.
Entering some data:
After clicking on [save]...
Validation error! (The model is not saved)
My ModelForm is quite simple: I am just changing the form field for one of the m2m model fields.
class News(models.Model):
departments = models.ManyToManyField(Department, blank=True, related_name='news', through='NewsDepartmentMembership')
research_groups = models.ManyToManyField(Group, blank=True, related_name='news', through='NewsGroupMembership')
related_news = models.ManyToManyField('self', blank=True, symmetrical=False)
people_involved = models.ManyToManyField(Person, blank=True, related_name='news')
title = models.CharField(_('Title'), max_length=255)
slug = models.SlugField(_('Slug'), unique_for_date='pub_date',
help_text=_('A slug is a short name which uniquely identifies the news item for this day'), )
excerpt = RichTextField(_('Excerpt'), blank=True)
content = RichTextField(_('Content'), blank=True)
is_published = models.BooleanField(_('Published'), default=False)
pub_date = models.DateTimeField(_('Publication date'), default=datetime.datetime.now)
is_feat = models.BooleanField(
_('Featured'), default=False,
help_text=_('Administrators may use this checkbox to promote news to the main news page')
)
published = PublishedNewsManager()
objects = models.Manager()
featured = FeaturedNewsManager()
class NewNewsForm(forms.ModelForm):
class Meta:
model = News
related_news = forms.ModelMultipleChoiceField(
queryset=News.objects.none(),
required=False,
widget=FilteredSelectMultiple(
verbose_name=_('articles'),
is_stacked=False,
)
)
def __init__(self, user=None, *args, **kwargs):
super(NewNewsForm, self).__init__(*args, **kwargs)
if hasattr(user, 'is_superuser'):
self.fields['related_news'].queryset = get_objects_for_user(user, ('news.change_news',)).filter(
is_published__exact=True).order_by('pub_date')
else:
self.fields['related_news'].queryset = News.published.order_by('pub_date')
if self.instance.pk:
self.fields['related_news'].initial = self.instance.related_news.all()
def save(self, commit=True):
news = super(NewNewsForm, self).save(commit=False)
if commit:
news.save()
if news.pk:
news.related_news = self.cleaned_data['related_news']
self.save_m2m()
return news
The ModelAdmin is quite complicated, it inherits 2 ModelAdmins. The 1st one comes from the django-modeltranslation package. I adapted the 2nd one from here, just to perform cross inline formsets validation. It's working in other packages without any problem (at least until today). I just have to override the method is_cross_valid to define the cross inline validation
class NewsAdmin(TranslationAdmin, ModelAdminWithInlines):
fields = ('title', 'slug_en', 'slug_nb', 'excerpt', 'content', 'is_published', 'pub_date', 'related_news', 'is_feat')
inlines = (DepartmentsNewsInline, GroupsNewsInline, PersonNewsInline)
form = NewNewsForm
prepopulated_fields = {'slug_en': ('title',), 'slug_nb': ('title',)}
class Media:
js = (
'http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js',
'http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.1/jquery-ui.min.js',
'modeltranslation/js/tabbed_translation_fields.js',
)
css = {
'screen': ('modeltranslation/css/tabbed_translation_fields.css',),
}
def queryset(self, request):
return get_objects_for_user(request.user, (u'news.change_news', ))
def formfield_for_manytomany(self, db_field, request=None, **kwargs):
if db_field.name == 'related_news':
return get_objects_for_user(request.user, ('news.change_news',), ).order_by('pub_date')
return super(NewsAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)
def is_cross_valid(self, request, form, formsets):
valid = True
# my validation code goes here...
return valid
def get_readonly_fields(self, request, obj=None):
if not request.user.groups.filter(name__exact='administration') and not request.user.is_superuser:
return ('is_feat', )
return ()
def has_change_permission(self, request, obj=None):
if super(NewsAdmin, self).has_change_permission(request, obj):
return True
return request.user.has_perm('news.change_news', obj)
This is my ModelAdminWithInlines, almost the same as here:
class ModelAdminWithInlines(ModelAdmin):
"""
Cross formsets validation. See https://stackoverflow.com/a/2746735
"""
def is_cross_valid(self, request, form, formsets):
"""
To perform cross-formset validation.
Should be overriden in every inheriting class.
"""
return True
def add_view(self, request, form_url='', extra_context=None):
"""The 'add' admin view for this model."""
model = self.model
opts = model._meta
if not self.has_add_permission(request):
raise PermissionDenied
ModelForm = self.get_form(request)
formsets = []
inline_instances = self.get_inline_instances(request, None)
if request.method == 'POST':
form = ModelForm(request.POST, request.FILES)
if form.is_valid():
new_object = self.save_form(request, form, change=False)
form_validated = True
else:
form_validated = False
new_object = self.model()
prefixes = {}
for FormSet, inline in zip(self.get_formsets(request), inline_instances):
prefix = FormSet.get_default_prefix()
prefixes[prefix] = prefixes.get(prefix, 0) + 1
if prefixes[prefix] != 1 or not prefix:
prefix = "%s-%s" % (prefix, prefixes[prefix])
formset = FormSet(data=request.POST, files=request.FILES,
instance=new_object,
save_as_new="_saveasnew" in request.POST,
prefix=prefix, queryset=inline.queryset(request))
formsets.append(formset)
# if all_valid(formsets) and form_validated:
formsets_validated = all_valid(formsets)
cross_validated = self.is_cross_valid(request, form, formsets)
if formsets_validated and form_validated and cross_validated:
self.save_model(request, new_object, form, False)
self.save_related(request, form, formsets, False)
self.log_addition(request, new_object)
return self.response_add(request, new_object)
else:
# Prepare the dict of initial data from the request.
# We have to special-case M2Ms as a list of comma-separated PKs.
initial = dict(request.GET.items())
for k in initial:
try:
f = opts.get_field(k)
except FieldDoesNotExist:
continue
if isinstance(f, ManyToManyField):
initial[k] = initial[k].split(",")
if ModelForm.Meta.model._meta.module_name == 'news' and ModelForm.Meta.model._meta.object_name == 'News':
form = ModelForm(initial=initial, user=request.user) # here I am injecting the user object into the form
# just to be able to access the objects for this user
else:
form = ModelForm(initial=initial)
prefixes = {}
for FormSet, inline in zip(self.get_formsets(request), inline_instances):
prefix = FormSet.get_default_prefix()
prefixes[prefix] = prefixes.get(prefix, 0) + 1
if prefixes[prefix] != 1 or not prefix:
prefix = "%s-%s" % (prefix, prefixes[prefix])
formset = FormSet(instance=self.model(), prefix=prefix,
queryset=inline.queryset(request))
formsets.append(formset)
adminForm = AdminForm(
form, list(self.get_fieldsets(request)),
self.get_prepopulated_fields(request),
self.get_readonly_fields(request),
model_admin=self)
media = self.media + adminForm.media
inline_admin_formsets = []
for inline, formset in zip(inline_instances, formsets):
fieldsets = list(inline.get_fieldsets(request))
readonly = list(inline.get_readonly_fields(request))
prepopulated = dict(inline.get_prepopulated_fields(request))
inline_admin_formset = InlineAdminFormSet(
inline, formset, fieldsets, prepopulated, readonly, model_admin=self
)
inline_admin_formsets.append(inline_admin_formset)
media = media + inline_admin_formset.media
context = {
'title': _('Add %s') % force_text(opts.verbose_name),
'adminform': adminForm,
'is_popup': "_popup" in request.REQUEST,
'media': media,
'inline_admin_formsets': inline_admin_formsets,
'errors': AdminErrorList(form, formsets),
'app_label': opts.app_label,
}
context.update(extra_context or {})
return self.render_change_form(request, context, form_url=form_url, add=True)
I really can't understand the source of my problem. Can anyone spot the issue?
Thanks!
UPDATE
As #GarryCairns suggested, I've tried to save an object from the shell. No problem with that.
>>> n = News.objects.create(title_en='test', slug_en='test', content_en='test')
>>> n.id
4
UPDATE 2:
Non translated fields are empty as well :-/
UPDATE 3:
>>> n = News()
>>> n
<News: >
>>> n.title_en = 'test'
>>> n.slug_en
>>> n.slug_en = 'test'
>>> n.content_en = 'blah blah'
>>> n.save()
>>> n.id
5
FIXED
It seems that both setting the ModelMultipleChoiceField queryset manually from the form init() and the NewsAdmin.formfield_for_manytomany() method were messing up the whole form data...