Django Nested Forms

Description

I use Django for all my web projects.

I like to simplify my applications'forms by nesting them, for example when users can add many photos on a product.

This class will help you to easily create nested forms in your project. I created this for a big project, with many nested forms, and many users love it every days.

Requirements

Django 1.2+ (should be compatible with 1.1, but not tested)

Usage

First of all, insert the nested_forms folder in in project's path.

In your forms.py

from nested_forms import ComplexModelForm

Make you main form inherit from ComplexModelForm

In Meta subclass of your ComplexModelForm, add :

formsets = {
}

This dict has for keys the related objects' names.

For the examples form Django's tutorial, we could write :

def get_choice_form(poll):
    class ChoiceForm(forms.ModelForm):
        class Meta:
            model = Choice
            exclude = ['poll']

        def save(self, commit=True):
            instance = super(ChoiceForm, self).save(commit=False)
            instance.poll = poll
            if commit:
                instance.save()
                self.save_m2m()
            return instance

    return ChoiceForm

class PollForm(ComplexModelForm):
    class Meta:
        model = Poll
        formsets = {
            'choice_set': {
                 'form': lambda instance: get_choice_form(instance),
                 'extra': 1,
                 'initial': [
                     {
                         'choice': 'A sample choice',
                         'votes': 0,
                     }
                 ],
            },
        }

You now have a nested form. Let's start using it in your template.

In your templates

Considering your nested form instance in a form variable in your context, you can access your access your form fields like any other forms. Your formsets are accessible by {{ form.formsets.[ name of related name of your object] }}. Don't forget to add the management form for each, and each formset is like any formset you would create manually. DON'T FORGET TO IMPLEMENT THE "ADD" TEMPLATE FILTER !

<form method="post">
    <fieldset>
        <legend>Poll</legend>
        {{ form.as_div }}

        {% with form.formsets.choice_set as choice_formset %}
            {{ choice_formset.management_form }}
            {% for choice_form in choice_formset.forms %}
            <fieldset>
            <legend>Choice {{ forloop.counter }}</legend>
            {{ choice_form.as_div }}
            </fieldset>
            {% endfor %}
            <button name="{{ choice_formset.prefix }}-TOTAL_FORMS" value="contact_formset.total_form_count|add:1">
                Add a choice
            </button>
        {% endwith %}
    </fieldset>
    <input type="submit" value="Save poll"/>
</form>