Initial Data for Django Inline Formsets

Question

I have put together a form to save a recipe. It makes use of a form and an inline formset. I have users with text files containing recipes and they would like to cut and paste the data to make entry easier. I have worked out how to populate the form portion after processing the raw text input but I cannot figure out how to populate the inline formset.

It seems like the solution is almost spelled out here: http://code.djangoproject.com/ticket/12213 but I can't quite put the pieces together.

My models:

#models.py

from django.db import models

class Ingredient(models.Model):
    title = models.CharField(max_length=100, unique=True)

    class Meta:
        ordering = ['title']

    def __unicode__(self):
        return self.title

    def get_absolute_url(self):
        return self.id

class Recipe(models.Model):
    title = models.CharField(max_length=255)
    description = models.TextField(blank=True)
    directions = models.TextField()

    class Meta:
        ordering = ['title']

    def __unicode__(self):
        return self.id

    def get_absolute_url(self):
        return "/recipes/%s/" % self.id

class UnitOfMeasure(models.Model):
    title = models.CharField(max_length=10, unique=True)

    class Meta:
        ordering = ['title']

    def __unicode__(self):
        return self.title

    def get_absolute_url(self):
        return self.id

class RecipeIngredient(models.Model):
    quantity = models.DecimalField(max_digits=5, decimal_places=3)
    unit_of_measure = models.ForeignKey(UnitOfMeasure)
    ingredient = models.ForeignKey(Ingredient)
    recipe = models.ForeignKey(Recipe)

    def __unicode__(self):
        return self.id

The recipe form is created using a ModelForm:

class AddRecipeForm(ModelForm):
    class Meta:
        model = Recipe
        extra = 0

And the relevant code in the view (calls to parse out the form inputs are deleted):

def raw_text(request):
    if request.method == 'POST':

    ...    

        form_data = {'title': title,
                    'description': description,
                    'directions': directions,
                    }

        form = AddRecipeForm(form_data)

        #the count variable represents the number of RecipeIngredients
        FormSet = inlineformset_factory(Recipe, RecipeIngredient, 
                         extra=count, can_delete=False)
        formset = FormSet()

        return render_to_response('recipes/form_recipe.html', {
                'form': form,
                'formset': formset,
                })

    else:
        pass

    return render_to_response('recipes/form_raw_text.html', {})

With the FormSet() empty as above I can successfully launch the page. I have tried a few ways to feed the formset the quantity, unit_of_measure and ingredients I have identified including:

• setting initial data but that doesn't work for inline formsets
• passing a dictionary, but that generates management form errors
• played around with init but I'm a bit out of my depth there

Any suggestions greatly appreciated.

Answer 1

My first suggestion would be to take the simple way out: save the Recipe and RecipeIngredients, then use the resulting Recipe as your instance when making the FormSet. You may want to add a "reviewed" boolean field to your recipes to indicate whether the formsets were then approved by the user.

However, if you don't want to go down that road for whatever reason, you should be able to populate your formsets like this:

We'll assume that you have parsed the text data into recipe ingredients, and have a list of dictionaries like this one:

recipe_ingredients = [
    {
        'ingredient': 2,
        'quantity': 7,
        'unit': 1
    },
    {
        'ingredient': 3,
        'quantity': 5,
        'unit': 2
    },
]

The numbers in the "ingredient" and "unit" fields are the primary key values for the respective ingredients and units of measure objects. I assume you have already formulated some way of matching the text to ingredients in your database, or creating new ones.

You can then do:

RecipeFormset = inlineformset_factory(
    Recipe,
    RecipeIngredient,
    extra=len(recipe_ingredients),
    can_delete=False)
formset = RecipeFormset()

for subform, data in zip(formset.forms, recipe_ingredients):
    subform.initial = data

return render_to_response('recipes/form_recipe.html', {
     'form': form,
     'formset': formset,
     })

This sets the initial property of each form in the formset to a dictionary from your recipe_ingredients list. It seems to work for me in terms of displaying the formset, but I haven't tried saving yet.