Inlineformset_factory widgets - object has no attribute 'attrs' error

Question

In django I've made this inlineformset_factory and I tried adding a widget to one of the fields. But I get the error that it is missing "attrs". I then add the "attrs" and I get another error saying "unexpected keyword argument 'attrs'"

Here is the inlineformset_factory.

UNIT_CHOICES = (('dl', 'dl'), ('l', 'l'), ('kg', 'kg'),)

IngredientFormSet = inlineformset_factory(RecipeModel, Ingredient, can_delete=False, extra=MAX_INGREDIENTS, exclude=[], 
    widgets={'unit_type': forms.ChoiceField(attrs={}, label="Måleenhet", required=True, widget=forms.Select, choices=UNIT_CHOICES)})

Here is the stuff I left out.

forms.py:

class AddRecipeForm(ModelForm):
    products = Product.objects.all()
    recipes = RecipeModel.objects.all()
    choices = ()
    iterate = 1
    for product in products:
        if not recipes.filter(title=product.name).exists():
            choices = ((product.name, product.name),) + choices
            iterate += 1
    title = forms.ChoiceField(label="Navn på produktet til oppskriften", required=True, widget=forms.Select, choices=choices)

    class Meta:
        model = RecipeModel
        exclude = []


class IngredientForm(ModelForm):
    title = forms.CharField(max_length=255, widget=TextInput(attrs={'id': 'ingredient_title',
                                                                    'class': 'ingredient_class'}))

    class Meta:
        model = Ingredient
        exclude = ['recipe']

views.py

def add_recipe(request):
    if request.POST:
        form = AddRecipeForm(request.POST)
        if form.is_valid():
            recipe = form.save(commit=False)
            ingredient_formset = IngredientFormSet(request.POST, instance=recipe)
            if ingredient_formset.is_valid():
                recipe.save()
                ingredient_formset.save()
                return redirect('admin_site')
            else:
                return redirect('admin_site')
        else:
            return redirect('admin_site')
    else:
        form = AddRecipeForm()
        ingredient_formset = IngredientFormSet(instance=RecipeModel())
    return render(request, 'admin/add_recipe.html', {
        'form': form,
        'ingredient_formset': ingredient_formset,
    }, context_instance=RequestContext(request))

models.py

class RecipeModel(models.Model):
    title = models.CharField("Navn på produktet", max_length=255, default="")
    kilogram_bottle = models.FloatField("Kg råvare for et produkt", blank=True)
    deciliter_bottle = models.FloatField("Deciliter råvare for et produkt", blank=True)
    description = models.TextField("Oppskrifts detaljer", default="")


class Ingredient(models.Model):
    recipe = models.ForeignKey(RecipeModel, on_delete=models.CASCADE)
    ingredient_title = models.CharField("Navn på ingrediens", max_length=255, default="")
    unit_before = models.FloatField("Råvare", blank=True, null=True)
    unit_after = models.FloatField("Ferdig behandlet råvare", blank=True, null=True)
    unit_type = models.CharField("Måleenhet", max_length=255)

Answer 1

Since you are specifying the widgets, you do not have to specify the field type again.

widgets={
    'unit_type': forms.Select
}

But it looks like you are trying to do a little more with the field, so you can create a modelform, and pass that as an argument.

class RecipeForm(forms.ModelForm):
    ...
    forms.ChoiceField(label="Måleenhet", required=True, widget=forms.Select(attrs={}), choices=UNIT_CHOICES)

inlineformset_factory(RecipeModel, Ingredient, form=RecipeForm, can_delete=False, extra=MAX_INGREDIENTS)

You can read more on this topic here

Also, note that attrs is an attribute on the widget, not the form field