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Django create form field with a model of the current user

I have a simple app, where a user has multiple businesses, and each business has multiple products, what I´m trying to do is a make product creatView, where i can select a business from the ones owned by the current user. I tryed editing the init() method of the ModelForm like this:
class Producto_Form(forms.ModelForm):
class Meta:
model = Producto_Model
fields = ("Nombre_Producto","Negocio","Descripcion_Producto",'Precio_Producto','Tags',"Foto")
def __init__(self, *args, **kwargs):
super(Producto_Form, self).__init__(*args, **kwargs)
self.fields['Negocio'].queryset = Negocio_Model.objects.all().filter(Administrador_id=kwargs['user'].id)
and then i changed the get_form_kwargs from the create product view like this:
class crear_producto(LoginRequiredMixin, CreateView):
template_name = "tienda/crear_producto.html"
form_class= Producto_Form
success_url = reverse_lazy('tienda_app:crear_producto')
login_url = reverse_lazy('register_app:logIn')
def get_form_kwargs(self, *args, **kwargs):
kwargs = super().get_form_kwargs(*args, **kwargs)
kwargs['user'] = self.request.user
return kwargs
I was following this question but I keep getting the error __init__() got an unexpected keyword argument 'user'

So everything is almost fine but you must pass the user variable to the form init as the kwargs, also, on the queryset dont call it like kwargs['user'] and just call user, something like this:
def __init__(self, user, *args, **kwargs):
super(Producto_Form, self).__init__(*args, **kwargs)
self.fields['Negocio'].queryset = Negocio_Model.objects.all().filter(Administrador_id=user.id)
also I changed the super() constructor on the get_form_kwargslike this:
def get_form_kwargs(self, *args, **kwargs):
kwargs = super(crear_producto, self).get_form_kwargs(*args, **kwargs)
kwargs['user'] = self.request.user
return kwargs

Form Problems - Setting Initial Value

I am trying to set the initial value of a field on a form. The field is not part of the model, but when I try and set it to a value the field is blank. From my research it could be because the form is "bound" which makes some sense to me, but in this case the field is not part of the model.
My form:
#Form for editing profile
class CatForm(forms.ModelForm):
pictureid = forms.CharField()
class Meta:
model = Cat
fields = ['name']
def __init__(self, *args, **kwargs):
picid = kwargs.pop("pictureid")
print(picid)
super(CatForm, self).__init__(*args, **kwargs)
self.fields['pictureid'] = forms.CharField(initial=picid, required=False)
The model:
class Cat(models.Model):
name = models.CharField(max_length=34,null=False)
From the view it is called like this:
catform = CatForm(request.POST, pictureid=instance.id)
I was expecting it to set the field to the value of the initial attribute, but it doesn't. I have tried testing it by directly adding a string, but doesn't set.
This is what seems to be working for me:
class CatForm(forms.ModelForm):
class Meta:
model = Cat
fields = ['name']
def __init__(self, *args, **kwargs):
picid = kwargs.pop("pictureid")
super(CatForm, self).__init__(*args, **kwargs)
self.fields['pictureid'] = forms.CharField(initial=picid)
I also needed to drop the "request.POST" from the call to this when initiating the form.

If you want to render the pictureid in GET request, then you can try like this:
catform = CatForm(initial={'pictureid': instance.id})
For GET request, you don't need to override the __init__ method.
But, if you want to use the Catform in POST request, to use the value of pictureid somewhere else(lets say in save method), then you will need to override __init__ method here.
class CatForm(forms.ModelForm):
pictureid = forms.CharField()
class Meta:
model = Cat
fields = ['name']
def __init__(self, *args, **kwargs):
picid = kwargs.pop("pictureid")
print(picid)
super(CatForm, self).__init__(*args, **kwargs)
self.pictureid = picid
def save(self, *args, **kwargs):
print(self.pictureid) # if you want to use it in save method
return super().save(*args, **kwargs)

How to add an initial/default value using Django Filters?

How can I add an initial/default value when using Django Filters?
For example, something like this initial=False
class UserFilter(django_filters.FilterSet):
archive = django_filters.BooleanFilter(initial=False)
class Meta:
model = User
fields = ['archive']
I've tired to override the __init__ but this does not appear to work.

You can try overriding the __init__ method of UserFilter:
def __init__(self, *args, **kwargs):
super(UserFilter, self).__init__(*args, **kwargs)
self.form.initial['archive'] = False

For DRF you can try override __init__:
def __init__(self, *args, **kwargs):
kwargs['data']._mutable = True
if 'archive' not in kwargs['data']:
kwargs['data']['archive'] = False
kwargs['data']._mutable = False
super(UserFilter, self).__init__(*args, **kwargs)
But you should read django-filter.readthedocs.io...using-initial-values-as-defaults

I had a similar problem in that I wanted to preserve the users selections even after they had navigated away from the page. I implemented my solution in the Filter View as follows...
class BucketLookupView(UserPassesTestMixin,SingleTableMixin,FilterView):
template_name = "finance/planning-bucket-lookup.html"
model = finance_models.SalesOrderBucket
filterset_class = finance_filters.BucketFilter
table_class = finance_tables.BucketTable
def get_filterset_kwargs(self,*args):
kwargs = super().get_filterset_kwargs(*args)
if kwargs['data']:
bucket_filter_data = kwargs['data']
self.request.session['bucket_filter_data']= bucket_filter_data
else:
if 'bucket_filter_data' in self.request.session.keys():
kwargs['data']=self.request.session['bucket_filter_data']
return kwargs

Here is an approximate code snippet I used:
def list(self, request, *args, **kwargs):
filters = QueryDict('is_archive=true', mutable=True)
filters.update(request.GET)
You build a new QueryDict as request.GET is immutable. Not that efficient, but looks pretty to me.

Here is a remix of #IlyaPetukhov's answer that I find easier to read:
def __init__(self, data=None, *args, **kwargs):
if data is not None:
data = data.copy()
data.setdefault("archive", False)
super(UserFilter, self).__init__(data, *args, **kwargs)
If you're uncomfortable with data = data.copy(), you can replace it with data._mutable = True; just know that it's not officially supported by Django.

form.cleaned_data is using to add filters to the queryset and no initial value is set for cleaned data.
The solution could be to override form property:
#property
def form(self) -> ModelForm:
form = super().form
form.data = form.data.copy()
form.data.setdefault("archive", False)
return form

Accessing parent model instance from modelform of admin inline

I'm using a TabularInline in Django's admin, configured to show one extra blank form.
class MyChildInline(admin.TabularInline):
model = MyChildModel
form = MyChildInlineForm
extra = 1
The model looks like MyParentModel->MyChildModel->MyInlineForm.
I'm using a custom form so I can dynamically lookup values and populate choices in a field. e.g.
class MyChildInlineForm(ModelForm):
my_choice_field = forms.ChoiceField()
def __init__(self, *args, **kwargs):
super(MyChildInlineForm, self).__init__(*args, **kwargs)
# Lookup ID of parent model.
parent_id = None
if "parent_id" in kwargs:
parent_id = kwargs.pop("parent_id")
elif self.instance.parent_id:
parent_id = self.instance.parent_id
elif self.is_bound:
parent_id = self.data['%s-parent'% self.prefix]
if parent_id:
parent = MyParentModel.objects.get(id=parent_id)
if rev:
qs = parent.get_choices()
self.fields['my_choice_field'].choices = [(r.name,r.value) for r in qs]
This works fine for the inline records bound to an actual record, but for the extra blank form, it doesn't display any values in my choice field, since it doesn't have any record id and there can't lookup the associated MyParentModel record.
I've inspected all the values I could find (args, kwargs, self.data, self.instance, etc) but I can't find any way to access the parent object the tabular inline is bound to. Is there any way to do this?

Update: As of Django 1.9, there is a def get_form_kwargs(self, index) method in the BaseFormSet class. Hence, overriding that passes the data to the form.
This would be the Python 3 / Django 1.9+ version:
class MyFormSet(BaseInlineFormSet):
def get_form_kwargs(self, index):
kwargs = super().get_form_kwargs(index)
kwargs['parent_object'] = self.instance
return kwargs
class MyForm(forms.ModelForm):
def __init__(self, *args, parent_object, **kwargs):
self.parent_object = parent_object
super(MyForm, self).__init__(*args, **kwargs)
class MyChildInline(admin.TabularInline):
formset = MyFormSet
form = MyForm
For Django 1.8 and below:
To pass a value of a formset to the individual forms, you'd have to see how they are constructed. An editor/IDE with "jump to definition" really helps here to dive into the ModelAdmin code, and learn about the inlineformset_factory and it's BaseInlineFormSet class.
From there you'll find that the form is constructed in _construct_form() and you can override that to pass extra parameters. It will likely look something like this:
class MyFormSet(BaseInlineFormSet):
def _construct_form(self, i, **kwargs):
kwargs['parent_object'] = self.instance
return super(MyFormSet, self)._construct_form(i, **kwargs)
#property
def empty_form(self):
form = self.form(
auto_id=self.auto_id,
prefix=self.add_prefix('__prefix__'),
empty_permitted=True,
parent_object=self.instance,
)
self.add_fields(form, None)
return form
class MyForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
self.parent_object = kwargs.pop('parent_object', None)
super(MyForm, self).__init__(*args, **kwargs)
class MyChildInline(admin.TabularInline):
formset = MyFormSet
form = MyForm
Yes, this involves a private _construct_form function.
update Note: This doesn't cover the empty_form, hence your form code needs to accept the parameters optionally.

I'm using Django 1.10 and it works for me:
Create a FormSet and put the parent object into kwargs:
class MyFormSet(BaseInlineFormSet):
def get_form_kwargs(self, index):
kwargs = super(MyFormSet, self).get_form_kwargs(index)
kwargs.update({'parent': self.instance})
return kwargs
Create a Form and pop an atribute before super called
class MyForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
parent = kwargs.pop('parent')
super(MyForm, self).__init__(*args, **kwargs)
# do whatever you need to with parent
Put that in the inline admin:
class MyModelInline(admin.StackedInline):
model = MyModel
fields = ('my_fields', )
form = MyFrom
formset = MyFormSet

AdminModel has some methods like get_formsets. It receives an object and returns a bunch of formsets. I think you can add some info about parent object to that formset classes and use it later in formset's __init__

Expanding on ilvar's answer a bit, If the form field of interest is constructed from a model field, you can use the following construction to apply custom behavior to it:
class MyChildInline(admin.TabularInline):
model = MyChildModel
extra = 1
def get_formset(self, request, parent=None, **kwargs):
def formfield_callback(db_field):
"""
Constructor of the formfield given the model field.
"""
formfield = self.formfield_for_dbfield(db_field, request=request)
if db_field.name == 'my_choice_field' and parent is not None:
formfield.choices = parent.get_choices()
return formfield
return super(MyChildInline, self).get_formset(
request, obj=obj, formfield_callback=formfield_callback, **kwargs)
return result

Creating a dynamic choice field

I'm having some trouble trying to understand how to create a dynamic choice field in django. I have a model set up something like:
class rider(models.Model):
user = models.ForeignKey(User)
waypoint = models.ManyToManyField(Waypoint)
class Waypoint(models.Model):
lat = models.FloatField()
lng = models.FloatField()
What I'm trying to do is create a choice Field whos values are the waypoints associated with that rider (which would be the person logged in).
Currently I'm overriding init in my forms like so:
class waypointForm(forms.Form):
def __init__(self, *args, **kwargs):
super(joinTripForm, self).__init__(*args, **kwargs)
self.fields['waypoints'] = forms.ChoiceField(choices=[ (o.id, str(o)) for o in Waypoint.objects.all()])
But all that does is list all the waypoints, they're not associated with any particular rider. Any ideas? Thanks.

you can filter the waypoints by passing the user to the form init
class waypointForm(forms.Form):
def __init__(self, user, *args, **kwargs):
super(waypointForm, self).__init__(*args, **kwargs)
self.fields['waypoints'] = forms.ChoiceField(
choices=[(o.id, str(o)) for o in Waypoint.objects.filter(user=user)]
)
from your view while initiating the form pass the user
form = waypointForm(user)
in case of model form
class waypointForm(forms.ModelForm):
def __init__(self, user, *args, **kwargs):
super(waypointForm, self).__init__(*args, **kwargs)
self.fields['waypoints'] = forms.ModelChoiceField(
queryset=Waypoint.objects.filter(user=user)
)
class Meta:
model = Waypoint

There's built-in solution for your problem: ModelChoiceField.
Generally, it's always worth trying to use ModelForm when you need to create/change database objects. Works in 95% of the cases and it's much cleaner than creating your own implementation.

the problem is when you do
def __init__(self, user, *args, **kwargs):
super(waypointForm, self).__init__(*args, **kwargs)
self.fields['waypoints'] = forms.ChoiceField(choices=[ (o.id, str(o)) for o in Waypoint.objects.filter(user=user)])
in a update request, the previous value will lost!

You can declare the field as a first-class attribute of your form and just set choices dynamically in __init__:
class WaypointForm(forms.Form):
waypoints = forms.ChoiceField(choices=[])
def __init__(self, user, *args, **kwargs):
super().__init__(*args, **kwargs)
waypoint_choices = [(o.id, str(o)) for o in Waypoint.objects.filter(user=user)]
self.fields['waypoints'].choices = waypoint_choices
This approach also works with a ModelChoiceField.
This approach is superior if you are using a ModelForm, and want to override choices of an autogenerated field.

How about passing the rider instance to the form while initializing it?
class WaypointForm(forms.Form):
def __init__(self, rider, *args, **kwargs):
super(joinTripForm, self).__init__(*args, **kwargs)
qs = rider.Waypoint_set.all()
self.fields['waypoints'] = forms.ChoiceField(choices=[(o.id, str(o)) for o in qs])
# In view:
rider = request.user
form = WaypointForm(rider)

If you need a dynamic choice field in django admin; This works for django >=2.1.
class CarAdminForm(forms.ModelForm):
class Meta:
model = Car
def __init__(self, *args, **kwargs):
super(CarForm, self).__init__(*args, **kwargs)
# Now you can make it dynamic.
choices = (
('audi', 'Audi'),
('tesla', 'Tesla')
)
self.fields.get('car_field').choices = choices
car_field = forms.ChoiceField(choices=[])
#admin.register(Car)
class CarAdmin(admin.ModelAdmin):
form = CarAdminForm
Hope this helps.

Underneath working solution with normal choice field.
my problem was that each user have their own CUSTOM choicefield options based on few conditions.
class SupportForm(BaseForm):
affiliated = ChoiceField(required=False, label='Fieldname', choices=[], widget=Select(attrs={'onchange': 'sysAdminCheck();'}))
def __init__(self, *args, **kwargs):
self.request = kwargs.pop('request', None)
grid_id = get_user_from_request(self.request)
for l in get_all_choices().filter(user=user_id):
admin = 'y' if l in self.core else 'n'
choice = (('%s_%s' % (l.name, admin)), ('%s' % l.name))
self.affiliated_choices.append(choice)
super(SupportForm, self).__init__(*args, **kwargs)
self.fields['affiliated'].choices = self.affiliated_choice

As pointed by Breedly and Liang, Ashok's solution will prevent you from getting the select value when posting the form.
One slightly different, but still imperfect, way to solve that would be:
class waypointForm(forms.Form):
def __init__(self, user, *args, **kwargs):
self.base_fields['waypoints'].choices = self._do_the_choicy_thing()
super(waypointForm, self).__init__(*args, **kwargs)
This could cause some concurrence problems, though.