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Django Admin - How to prefill add inline forms values sent through the querystring?

I am able to prefill a form using query-string parameters in Django Admin.
Let's say I have the following models:
class Book(models.Model):
id = models.Autofield(primary_key=True)
author = models.ForeignKey(Author, on_delete=models.CASCADE)
name = models.Charfield(max_length=200)
class Author(models.Model):
id = models.Autofield(primary_key=True)
name = models.Charfield(max_length=200)
If I go to /admin/library/author/add/?name=J.+K.+Rowling the author's name will be properly prefilled.
However if I add InlineForms like that:
class BookInline(StackedInline):
model = Book
extra = 0
class AuthorAdmin(ModelAdmin):
inlines = [BookInline]
admin.site.register(Author, AuthorAdmin)
I don't seem to be able to prefill books.
I tried: /admin/library/author/add/?name=J.+K.+Rowling&books-TOTAL_FORMS=1&books-0-name=Harry+Potter+and+the+Philosopher's+Stone
The author form is prefilled, but the first book form is not prefilled. Do you know how one manages that?

If you override get_formset_kwargs, you can prefill forms with some initial values:
class AuthorAdmin(ModelAdmin):
inlines = [BookInline]
def get_formset_kwargs(self, request, obj, inline, prefix):
formset_params = super().get_formset_kwargs(request, obj, inline, prefix)
if request.method == "GET":
# Mind you, this will prefill all form of the formset with the same values.
# But for our usecase it is sufficient.
prefix_length = len(prefix) + 3
initial_values = [{key[prefix_length:]: value for key, value in request.GET.items() if key.startswith(prefix)}]
formset_params.update(initial=initial_values)
return formset_params
However, all extra form will contain the same values.
If you know how we can manage to use the index there, it would improve this answer.

Django modelformset with customized model initialization

I have the following models in django:
class tag(models.Model):
...
user = models.ForeignKey(user)
shop = models.ForeignKey(shop)
name = models.CharField()
...
class user(models.Model):
...
name = models.CharField()
...
class shop(models.Model):
...
user = models.ForeignKey(user)
name = models.CharField()
...
Now I need to create a modelformset of tag model that will allow me to store bunch of different tags per user. What I am looking for is a way to initialize such formset with a shop field filtered out for a given user.
This way my forms would have a selection of shops that are assigned to the user.
Any ideas are very welcome!
Thanks

You can use inlineformset_factory to create a formset for related models. To create a formset for your tag and user model you can do the following:
tag_formset = inlineformset_factory(user, tag, fields=['shop', 'name'])
formset = tag_formset(instance=request.user)
To filter the queryset for the shop field you can either create a form dynamically or pass formfield_callback to the factory function.
If you use formfield_callback, this callback can be used to return a custom field for your form
def cb(field, **kwargs):
if field.name == 'shop':
kwargs['queryset'] = shop.objects.filter(user=request.user)
return field.formfield(**kwargs)
tag_formset = inlineformset_factory(user, tag, fields=['shop', 'name'], formfield_callback=cb)
formset = tag_formset(instance=request.user)
Or you can define a form class dynamically in your view
class TagForm(forms.ModelForm):
shop = forms.ModelChoiceField(shop.objects.filter(user=request.user))
class Meta:
fields = ['shop', 'name']
tag_formset = forms.inlineformset_factory(user, tag, form=TagForm)
formset = tag_formset(instance=request.user)

Django form custom field

If we have a modelForm with some fields not directly corresponding to the model, how do we have the form process them in a custom way, while saving the rest of fields as by default?
For example, we have a model for an item that supports multilingual descriptions. The models are:
class Item(models.Model):
name = models.ForeignKey(Localization)
on_sale = models.BooleanField(default=False)
class Localization(models.Model):
de = models.TextField(blank=True, null=True, verbose_name='de')
eng = models.TextField(blank=True, null=True, verbose_name='eng')
The form to add/edit an Item looks like that:
class ItemForm(forms.ModelForm):
id = forms.CharField(widget=forms.HiddenInput(), max_length=128, label='')
name_eng = forms.CharField(widget=forms.TextInput(attrs={'style': 'width:200px;'}), label='eng')
name_de = forms.CharField(widget=forms.TextInput(attrs={'style': 'width:200px;'}), label='de')
on_sale = forms.CharField(widget=forms.CheckboxInput(), label='on_sale', )
class Meta:
model = Item
fields = ('id', 'on_sale',)
Now what saving this form should do, is for a new Item - create Localization object with the two name fields, then create an Item object with on_sale field, linked to Localization object. For an existing Item - edit the corresponding Localization object and then on_sale field of the Item itself.
I did the task with a separate function, that processes the custom fields from the request separately, but having it all done by the form's save() method looks better. Or am I wrong?
PS I'm sorry to be asking an evidently worn question, but I simply fail to do what I want with other examples.
Update:
I actually got it working the way I wanted with the help of the hints from here. Code goes as that, please let me know if it can be optimized.
class NameForm(forms.ModelForm):
# id = forms.CharField(widget=forms.HiddenInput(), max_length=128, label='')
id = forms.CharField(widget=forms.TextInput(attrs={'style': 'width:200px;'}), label='id', required=False)
name_eng = forms.CharField(widget=forms.TextInput(attrs={'style': 'width:200px;'}), label='eng')
name_de = forms.CharField(widget=forms.TextInput(attrs={'style': 'width:200px;'}), label='de')
gender = forms.CharField(widget=forms.CheckboxInput(), label='gender', required=False)
class Meta:
model = Name
fields = ('id', 'gender',)
def save(self):
instance = super(NameForm, self).save(commit=False)
obj_id = self.cleaned_data['id']
if obj_id:
instance_bd = Name.objects.get(pk=obj_id)
loc = instance_bd.name
loc.de = self.cleaned_data['name_de']
loc.eng = self.cleaned_data['name_eng']
loc.save()
instance.id = obj_id
else:
loc = Localization(de=self.cleaned_data['name_de'], eng=self.cleaned_data['name_eng'])
loc.save()
instance.name = loc
instance.save()
return instance
The view is simply
#login_required
def admin_lists(request):
if request.method == 'POST':
form = NameForm(request.POST)
if form.is_valid():
form.save()
forms = {'name': NameForm()}
return render(request, 'admin/lists.html', {'forms': forms})

In this case is better don't use the forms'save method, try this
if request.method == 'POST':
form = ItemForm(request.POST)
# check whether it's valid:
if form.is_valid():
post = request.POST
set_name_eng= post['name_eng']
set_name_de= post['name_de']
set_on_sale = post['on_sale']
#now here we create the anothers objects
a = Localization(de=set_name_de, eng=set_name_eng)
a.save()
b = Item(name=a, on_sale=sale)
b.save()
I didn't understand the last part, but I think you need to organize better your models and forms, Let me know and I'll try to help you

Dynamic Fields ModelForms Django

I am trying to figure out how to dynamically change a ModelForm field based on the input from a previous field.
For example, if I have these kinds of models:
class Phone(models.Model):
name = models.CharField(max_length=10)
class Series(models.Model):
name = models.CharField(max_length=10)
class Manufacturer(models.Model):
phone = models.ForeignKey('Phone')
series = models.ForeignKey('Series')
class ManufacturerForm(ModelForm):
class Meta:
model = Manufacturer
Which would generate a form (ManufacturerForm) with dropdown options for the phone and series entries in the database. Is it possible to a different set of series entries based on the phone entered by the user, for example?
I have read about using the __init__ method to accomplish this, based on what I have read on this blog post, but I am not sure how to execute this given my scenario. Or maybe there is a better way to go about achieving this that you have taken? Thanks for any advice!
EDIT: Added the form's view.
def make_ad(request):
if request.method == 'POST':
form = ManufacturerForm(request.POST, request.FILES)
if form.is_valid():
a = form.save()
a.user = request.user
a.save()
else:
form = ManufacturerForm()
variables = RequestContext(request, {
'form': form
})
return render_to_response('place.html', variables)
#super9 mentioned using ajax request to change these elements. I need to check if request.is_ajax(), but at what point should I check this in my view? And how do I add or change the queryset based on the ajax request?
Thanks for your advice.
EDIT: Trying to use django-smart-selects
Not sure how to setup my models to utilize django-smart-selects to accomplish what I am trying. Here is how I have structured my models:
from smart_selects.db_fields import ChainedForeignKey
class Phone(models.Model):
phone = models.CharField(max_length=10)
class Series(models.Model):
series = models.CharField(max_length=10)
phone = models.ForeignKey(Phone)
class SeriesModel(models.Model):
model = models.CharField(max_length=10)
series = models.ForeignKey(Series)
class Manufacturer(models.Model):
phone = models.ForeignKey(Phone)
series = ChainedForeignKey (Series, chained_field = "phone", chained_model_field = "phone")
series_model = ChainedForeignKey (SeriesModel, chained_field = "series", chained_model_field = "series")
But when I view my form (ModelForm) the fields for series_model are not chained properly to series. Am I missing something to make smart-selects work on the second layer of abstraction?
EDIT: Above code now works.

how can I save a form with ModelMultipleChoiceField?

I have a model Calendar and in a form I want to be able to create multiple instances of it.
Here are my models:
class Event(models.Model):
user = models.ForeignKey(User)
class Group(models.Model):
name = models.CharField(_('Name'), max_length=80)
events = models.ManyToManyField(Event, through='Calendar')
class Calendar(models.Model):
event = models.ForeignKey(Event)
group = models.ForeignKey(Group)
class CalendarInline(admin.TabularInline):
model = Calendar
extra = 1
class GroupAdmin(admin.ModelAdmin):
inlines = (CalendarInline,)
Here is how I try to code my form:
class AddEventToGroupForm(ModelForm):
group = ModelMultipleChoiceField(queryset=Group.objects.all(), widget=SelectMultiple())
def save(self):
for g in self:
g.save()
class Meta:
model = Calendar
fields = ('group',)
And here is a part of my view:
e = Event.objects.get(id=event_id)
calentry = Calendar(event=e)
if request.POST:
f = AddEventToGroupForm(data=request.POST, instance=calentry)
if f.is_valid():
f.save()
If I try to submit that form, I get:
AttributeError at /groups/add_event/7/
'BoundField' object has no attribute 'save'
What is the proper way to create multiple instances of Calendar in this
situation?

That's not how to deal with many-to-many relationships in forms. You can't iterate through fields in a form and save them, it really doesn't work that way.
In this form, there's only one field, which happens to have multiple values. The thing to do here is to iterate through the values of this field, which you'll find in the cleaned_data dictionary (when the form is valid).
So, in your view, you do something like:
if f.is_valid():
for group in f.cleaned_data['group']:
calentry.groups.add(group)
Note you're not 'saving' the AddEventToGroupForm form at all. I would make it a standard forms.Form, rather than a ModelForm, as you're not really depending on any of the ModelForm functionality.