CODEWITHSUNDEEP
pythondjango
pete
pete

Reputation: 2799

Django: Multiple forms possible when using FormView?

I've recently learned Django forms by subclassing FormView, where the desired form is assigned to the FormView.form_class attribute. When the form validates, the form_valid() method is invoked (for that one form). For example:

from accounts.forms import SignUpForm, UpdateAccountForm, UpdateBillingForm

class SignUpView(FormView):
    form_class = SignUpForm

    def form_valid(self, form):
    # code when form validates...

However, I now have a situation where I need three unique forms on one page (with only one form visible to the user at a time). So, I'd like to handle them all in the same View.

Are multi-form pages possible using FormView? I'm not sure how to handle it, both in terms of passing multiple forms to the View (e.g. the other UpdateAccountForm and UpdateBillingForm), as well as distinguishing which one was submitted/validated? What would be the best way?

Upvotes: 20

Views: 13131

Answers (2)

pete
pete

Reputation: 2799

Well, for what it's worth here's what ultimately worked for me, using a generic View.

1) I added a hidden input field (named 'action') to each individual form on the page. For example, this is the form for updating user's info, which is pulling in UserForm:

<form action='/account/' method='post'>{% csrf_token %}
   <input type='hidden' name='action' value='edit_user'> 
   {{ user_form.as_p }}
   <input type='submit' value='Update'>
</form>

2) In my View logic, I can distinguish the forms by applying a prefix (per other SO posts and Django docs). Then, depending on the incoming 'action', I only bind the applicable form to the POST request (so validations aren't applied across all of them). In my case, I had two forms defined in forms.py, UserForm and BillingForm: 

from django.views.generic.edit import View
from django.shortcuts import render
from django.http import HttpResponse

from accounts.forms import UserForm, BillingForm

class AccountView(View):

    def get(self, request):
        # code for GET request...

    def post(self, request):
        #instantiate all unique forms (using prefix) as unbound
        user_form    = UserForm(prefix='user_form')
        billing_form = BillingForm(prefix='billing_form')

        # determine which form is submitting (based on hidden input called 'action')
        action = self.request.POST['action']

        # bind to POST and process the correct form
        if (action == 'edit_user'):
            user_form = UserForm(request.POST, prefix='user_form')
            if user_form.is_valid():
                # user form validated, code away..

        elif (action == 'edit_billing'):
            billing_form = BillingForm(request.POST, prefix='billing_form')
            if billing_form.is_valid():
                # billing form validated, code away..

        # prep context
        context = {
            'user_form':    user_form,
            'billing_form': billing_form,
        }
        return render(request, 'accounts/account.html', context)

Seems to work well, hopefully this is the right approach (?)

Upvotes: 27

bruno desthuilliers
bruno desthuilliers

Reputation: 77912

You can write a plain python class mimicking the Form API (at least the useful parts) and wrapping your three forms. Detecting which form has been submitted is just a matter of adding a hidden input with the form's identifier in each form (hint : use prefixes for your forms and use that same prefix as identifier).

The other solution is to use a simple function-based view instead, but even there I'd still use the same "form wrapper" pattern as far as I'm concerned.

Upvotes: 1

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