Question

If I create a formset using modelformset_factory like this:

 IngredientFormSet = modelformset_factory(RecipeIngredients, form=RecipeIngredientsForm)
 formset = IngredientFormSet(request.POST)

and my form looks like this

class RecipeIngredientsForm(forms.ModelForm):
    Ingredient = forms.CharField(max_length= 100)
    class Meta:
        model = RecipeIngredients
        exclude = ('weightmetric','recipe')

Where would I put my custom .save() method? Would I put it under the RecipeIngredientsForm?

[a potential solution]

In your view do something like this:

 if formset.is_valid():
        for form in formset:
            obj = form.save(commit=False) #obj = RecipeIngredient model object
            try:
                ingredient_in_db = Ingredient.objects.get(name = form.cleaned_data.get('ingredientform'))
            except:
                ingredient_in_db = None
            if ingredient_in_db:
                obj.ingredient = ingredient_in_db
            else:
                new_ingredient = Ingredient.objects.create(name = form.cleaned_data.get('ingredientform'))
                obj.ingredient = new_ingredient
            obj.recipe = recipeobj
            obj.save()

Incidentally, I think this method would also allow me to do a custom .save(), given that I take each form in the formset and do a form.save(commit= False) on it. It was easier though, to just do it in my view, since I needed access to the recipe object.

Answer 1

I’m not sure of the best way to override the existing save() method on the BaseModelForm. My guess is that you actually would want to either:

1. Create your own field that has it’s own to_python() method which will take the text and find/create the associated object.

   class IngredientField(forms.CharField):
       def to_python(self, value):
           # Lookup model or create new one
           ingredient = models.Ingredient.objects.get(name=value)
           if not ingredient:
               ingredient = models.Ingredient.create(name=value)
           return ingredient
   

2. Use save(commit=False) on the formset, do the ingredient lookup/creation, and then commit afterwards