Difficulty with validation of multiple modelforms on 1 page

[Roald]

Hi all,

I'm working on an application that uses a HTML-form consisting of multiple Django-ModelForms. Moreover, their validation is interdependent. Moreover, their data is interdependent. Moreover, I use multiple modelforms with the same instance (might be a bad idea anyway). My template looks something like this:

<form ...>

  {% if forms.a %}

    {{ forms.a }}

  {% endif %}

  {{ forms.b }}

  {# and much more of that #}

  ...

</form>

My view looks something like this:

if all([f.is_valid() for k, f in forms.items() if f is not None]):

    if forms['a']:

        a = forms['a'].save()

        a.b = forms['b'].save()

        a.b.c = forms['c'].save()

        a.x = forms['d'].save(commit=false).x

        a.save()

    # and much more such stuff

    ...

Do you have any opinions/pointers on how to do this (most elegantly)? Especially how I can validate one form based on the (cleaned) data of another form? Or how you would  refactor that? Thanks in advance!

Kind regards, Roald