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Manually set model fields in ModelForm

I have a model with a foreign key and a unique constraint as follows:
class Menu(models.Model):
tournament = models.ForeignKey(Tournament, on_delete=models.CASCADE)
name = models.CharField(max_length=128)
date_menu = models.DateField()
class Meta:
constraints = [
models.UniqueConstraint(fields=['tournament', 'name', 'date_menu'], name="unique_name_menu")
]
I would like to create a form to add instance of Menu. However the value of tournament is set by the URL of the page. I do not want the user to be able to set it.
For this I use a modelForm, excluding the tournament field :
class MenuForm(forms.ModelForm):
date_menu = forms.DateField(initial=datetime.datetime.now())
class Meta:
model = Menu
exclude = ['tournament']
Here is my view :
def add_menu(request, tournament_slug):
tournament = get_object_or_404(Tournament, slug=tournament_slug)
form = MenuForm(request.POST or None)
if form.is_valid():
menu_id = form.save(commit=False)
menu_id.tournament = Tournament.objects.get(pk=1)
menu_id.save() # I get the integrity error only here
return HttpResponseRedirect(reverse('admin'))
return render(request, "view.html", {'form': form, 'formset': formset, "tournament": tournament})
My problem is that when I call the .is_valid() function on this form the uniqueness condition cannot be checked as the tournament field is not set. As a result I get an integrity error when calling the save function in the view.
The question is : how can link the Menu instance created by the form to add the tournament field before checking if it's valid? If it's not the right way of doing it, how can I check the uniqueness of the model instance and return the corresponding errors to the template when needed?
I tried including the tournament field as hidden field in the view, it works but I don't know if that's the best way of doing it...

You should simply instantiate the form with an unsaved instance of Menu so your view should be like:
def add_menu(request, tournament_slug):
tournament = get_object_or_404(Tournament, slug=tournament_slug)
if request.method == 'POST':
form = MenuForm(request.POST, instance=Menu(tournament=tournament))
if form.is_valid():
menu_id = form.save()
return HttpResponseRedirect(reverse('admin'))
else:
form = MenuForm(instance=Menu(tournament=tournament))
return render(request, "view.html", {'form': form, "tournament": tournament})
Also the form calls _get_validation_exclusions() and excludes fields not present in the form from validation. You can try to override validate_unique to overcome this:
class MenuForm(forms.ModelForm):
date_menu = forms.DateField(initial=datetime.datetime.now())
class Meta:
model = Menu
exclude = ['tournament']
def validate_unique(self):
exclude = self._get_validation_exclusions()
if 'tournament' in exclude:
exclude.remove('tournament') # Make sure `tournament` gets validated
try:
self.instance.validate_unique(exclude=exclude)
except ValidationError as e:
self._update_errors(e)
Note: I changed your view structure to avoid using MenuForm(request.POST or None) which is an antipattern. (Forms
can be valid even if nothing is sent in the POST data, with the way
you write such forms would be considered invalid).
Edit: As discussed in the comments perhaps the option of a hidden and disabled field is much better than overriding the forms validate_unique method:
class MenuForm(forms.ModelForm):
tournament = forms.ModelChoiceField(
queryset=Tournament.objects.all(),
widget=forms.HiddenInput(),
disabled=True
)
date_menu = forms.DateField(initial=datetime.datetime.now())
class Meta:
model = Menu
fields = ['tournament', 'name', 'date_menu']

Django ForeignKey is returning ID number instead of actual string value, particularly for form-based request.POST

I have a website contact form that generates a dropdown box of "names" that are defined in another model "Data". The contact form runs off the model "Quote". As such, I use a ForeignKey reference to populate the "Data" information within the "Quote"-driven form.
However, the next step is to move this data to more python code (i.e., for calculations and placement in an email). But, when I request.POST "name" in the quote views file, I receive an ID (i.e., 1) instead of the actual string value for "name." I have read this is how ForeignKey inherently transfers data.
Like how I returned the actual string version of "name" in the quote dropdown box, how do I get the actual string version of "name" in a data request.POST / data_dictionary assignment? I have seen similar questions, but I am not completely sure of the simplest answer.
models.py (Original one)
class Data(models.Model):
name = models.CharField(max_length=100, null=True)
def __str__(self):
return self.name
models.py (The one tied to the form)
class Quote(models.Model):
name = models.ForeignKey(Data, on_delete=models.CASCADE)
def __str__(self):
return str(self.name)
views.py
def quote_req(request):
submitted = False
if request.method == 'POST':
form = QuoteForm(request.POST, request.FILES)
name = request.POST['name']
if form.is_valid():
data_dict = {
'name_': str(name),
inputdictionary = data_dict
forms.py
class QuoteForm(ModelForm):
helper = FormHelper()
helper.form_show_labels = False
required_css_class = 'required'
class Meta:
model = Quote
fields = ['name',]
Variable Assignment
▼ Local vars
Variable Value
name '1'
Respective Error (I need the actual string value of "name")
IndexError at /quote/
list index out of range

The solution was in tandem with what #dirkgroten mentioned in the comments. I have to add the form.cleaned_data method after the if form.is_valid statement. No other files need to be modified.
views.py
def quote_req(request):
submitted = False
if request.method == 'POST':
form = QuoteForm(request.POST, request.FILES)
name = request.POST['name']
if form.is_valid():
name = form.cleaned_data['name']
data_dict = {
'name_': str(name),
inputdictionary = data_dict

django - form.cleaned_data[] for all fields in model

I am using django to digitalise a form. This form is a little bit complex, and there are a lot of fields in it. I was wondering if Django could do form.cleaned_data[] for all fields, in stead of declaring variables like obj.fieldname = form.cleaned_data['fieldname'] for each field apart.
I tried it with a forloop in the views.py, but that won't work
This is the forloop I'm talking about:
def get_form_naw(request):
if request.method == 'POST':
form = Form1(request.POST)
if form.is_valid():
for x in Model1():
formname = x.name
o = Model1()
o.formname = form.cleaned_data[formname]
o.save()
else:
form = Form1
return render(request, 'folder/home.html', context=locals())
I'm using a mysql database. My forms are declared like this:
forms.py
class Form1(forms.ModelForm):
class Meta:
model = Model1
exclude = ('id')

You shouldn't have to loop through the fields. You are using a model form, so you should just save the form:
if form.is_valid():
obj = form.save()
...
If you really need to set fields dynamically, you can use setattr.
fieldname = 'username'
value = 'my_user'
setattr(obj, fieldname, value)

you can get the instance of the data before saving like this:
if form.is_valid():
obj = form.save(commit=False) #get instance without saving
# do your thing
obj.save() #save into database

Django: how to loop through boolean fields and set all to false

So, I have a table called "order" that has a foreign key with the table "store". The order table has a boolean field set by default to false. When a new order is created, I need to loop through the boolean values associated with each individual store and set the other orders to false and the new order to true. Not sure how to create the for loop for that. First I tried to set it into the view, but maybe it can be put into the forms.py file? This my create code so far.
def create(request):
if request.POST:
form = OrderForm(request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect('/liquors/all')
else:
form = OrderForm()
args = {}
args.update(csrf(request))
args['form'] = form
return render_to_response('create_order.html', args)
Models provided upon request, you shouldn't need anything except the order model:
class Order(models.Model):
OrderID = models.AutoField(primary_key=True)
storeID = models.ForeignKey(Store)
DateCreated = models.DateField('Date Created', auto_now_add=True)
OrderName = models.CharField('Order Name', max_length=25 )
Active = models.BooleanField()

you must return render_to_response('create_order.html', args) one indentation back. so that validation form will not affected. you don't need to use csrf request if you are using render. I think there is no need to use OrderId in Order model, since it is automattically created. ie id
from django.shortcuts import render
from <appname>.models import Order,Store
def create(request):
if request.POST:
form = OrderForm(request.POST)
if form.is_valid():
#i just assume the storeid variable is exist in request.POST and it is ID.
store_data=Store.objects.get(id=request.POST['storeid'])
#here you might need to update the other orderform to false
Order.objects.filter(storeID=store_data).update(Active=False)
fo=Order(storeID=store_data,Active=True)
frm_order=OrderForm(request.POST,instance=fo)
frm_order.save()
return HttpResponseRedirect('/liquors/all')
else:
form = OrderForm()
return render(request,'create_order.html', {'form':form})

You can use the order object's meta object to loop through the fields. Ex.
for field in order._meta.fields():
if type(field) = django.db.models.fields.BooleanField:
setattr(order, field.name, True)

Django set default form values

I have a Model as follows:
class TankJournal(models.Model):
user = models.ForeignKey(User)
tank = models.ForeignKey(TankProfile)
ts = models.IntegerField(max_length=15)
title = models.CharField(max_length=50)
body = models.TextField()
I also have a model form for the above model as follows:
class JournalForm(ModelForm):
tank = forms.IntegerField(widget=forms.HiddenInput())
class Meta:
model = TankJournal
exclude = ('user','ts')
I want to know how to set the default value for that tank hidden field. Here is my function to show/save the form so far:
def addJournal(request, id=0):
if not request.user.is_authenticated():
return HttpResponseRedirect('/')
# checking if they own the tank
from django.contrib.auth.models import User
user = User.objects.get(pk=request.session['id'])
if request.method == 'POST':
form = JournalForm(request.POST)
if form.is_valid():
obj = form.save(commit=False)
# setting the user and ts
from time import time
obj.ts = int(time())
obj.user = user
obj.tank = TankProfile.objects.get(pk=form.cleaned_data['tank_id'])
# saving the test
obj.save()
else:
form = JournalForm()
try:
tank = TankProfile.objects.get(user=user, id=id)
except TankProfile.DoesNotExist:
return HttpResponseRedirect('/error/')

You can use Form.initial, which is explained here.
You have two options either populate the value when calling form constructor:
form = JournalForm(initial={'tank': 123})
or set the value in the form definition:
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)

Other solution: Set initial after creating the form:
form.fields['tank'].initial = 123

If you are creating modelform from POST values initial can be assigned this way:
form = SomeModelForm(request.POST, initial={"option": "10"})
https://docs.djangoproject.com/en/1.10/topics/forms/modelforms/#providing-initial-values

I had this other solution (I'm posting it in case someone else as me is using the following method from the model):
class onlyUserIsActiveField(forms.ModelForm):
def __init__(self, *args, **kwargs):
super(onlyUserIsActiveField, self).__init__(*args, **kwargs)
self.fields['is_active'].initial = False
class Meta:
model = User
fields = ['is_active']
labels = {'is_active': 'Is Active'}
widgets = {
'is_active': forms.CheckboxInput( attrs={
'class': 'form-control bootstrap-switch',
'data-size': 'mini',
'data-on-color': 'success',
'data-on-text': 'Active',
'data-off-color': 'danger',
'data-off-text': 'Inactive',
'name': 'is_active',
})
}
The initial is definded on the __init__ function as self.fields['is_active'].initial = False

As explained in Django docs, initial is not default.
The initial value of a field is intended to be displayed in an HTML . But if the user delete this value, and finally send back a blank value for this field, the initial value is lost. So you do not obtain what is expected by a default behaviour.
The default behaviour is : the value that validation process will take if data argument do not contain any value for the field.
To implement that, a straightforward way is to combine initial and clean_<field>():
class JournalForm(ModelForm):
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
(...)
def clean_tank(self):
if not self['tank'].html_name in self.data:
return self.fields['tank'].initial
return self.cleaned_data['tank']

If you want to add initial value and post other value you have to add the following :
or None after request.POST
form = JournalForm(request.POST or None,initial={'tank': 123})
If you want to add files or images also
form = JournalForm(request.POST or None,request.FILES or None,initial={'tank': 123})

I hope this can help you:
form.instance.updatedby = form.cleaned_data['updatedby'] = request.user.id

I also encountered the need to set default values in the form during development. My solution is
initial={"":""}
form=ArticleModel(request.POST)
if form.has_changed():
data = {i: form.cleaned_data[i] for i in form.changed_data}
data.update({key: val for key, val in init_praram.items() if key not in form.changed_data})
use form.has_changed ,if form.fields is required you can use this method

How I added the initial to the form:
I read #Sergey Golovchenko answer.
So I just added it to the form in if request.method == 'POST':.
But that's not where you place it, if you want to see what value it got before posting the form.
You need to put it in the form where the else is.
Example here from views.py
def myForm(request):
kontext = {}
if request.method == 'POST':
# You might want to use clean_data instead of initial here. I found something on a stack overflow question, and you add clean data to the Forms.py, if you want to change the post data. https://stackoverflow.com/questions/36711229/django-forms-clean-data
form = myModelForm(request.POST, initial={'user': request.user})
if form.is_valid():
form.save()
return redirect('/')
else:
# you need to put initial here, if you want to see the value before you post it
form = myModelForm(initial={'user': request.user})
kontext['form'] = form
return render(request, 'app1/my_form.html', kontext)