Question

The suggested pattern for processing a form in a view seems overly complex and non-DRY to me:

def contact(request):
    if request.method == 'POST': # If the form has been submitted...
        form = ContactForm(request.POST) # A form bound to the POST data
        if form.is_valid(): # All validation rules pass
            # Process the data in form.cleaned_data
            # ...
            return HttpResponseRedirect('/thanks/') # Redirect after POST
    else:
        form = ContactForm() # An unbound form

    return render_to_response('contact.html', {
        'form': form,
    })

That’s a lot of conditionals, it repeats the ContactForm() construction, and the whole block is repeated everywhere a view needs to process a form. Isn’t there a better way of doing it?

Answer 1

You can avoid the repetition, of course. Mostly, you need to pass in as arguments the class of form and template name to use, a callable to process the cleaned data when a valid form is submitted, and a destination for the redirect after such processing; plus, you need a little extra code to call the form class just once, to produce either a bound or unbound form, and deal with it properly. I.e.:

def process_any_form(request, 
                     form_class, template_file_name,
                     process_data_callable, redirect_destination):

    form = form_class(request.POST if request.method == 'POST' else None)

    if form.is_bound and form.is_valid():
        process_data_callable(form.cleaned_data)
        return HttpResponseRedirect(redirect_destination)

    return render_to_response(template_file_name, {'form': form})