django multiform mixin and view that allows the submission of a) All forms b) Grouped forms c) An individual form

multiform.py

class MultiFormMixin(ContextMixin):

    form_classes = {} 
    prefixes = {}
    success_urls = {}
    grouped_forms = {}
    
    initial = {}
    prefix = None
    success_url = None
     
    def get_form_classes(self):
        return self.form_classes
     
    def get_forms(self, form_classes, form_names=None, bind_all=False):
        return dict([(key, self._create_form(key, klass, (form_names and key in form_names) or bind_all)) \
            for key, klass in form_classes.items()])
    
    def get_form_kwargs(self, form_name, bind_form=False):
        kwargs = {}
        kwargs.update({'initial':self.get_initial(form_name)})
        kwargs.update({'prefix':self.get_prefix(form_name)})
        
        if bind_form:
            kwargs.update(self._bind_form_data())

        return kwargs
    
    def forms_valid(self, forms, form_name):
        form_valid_method = '%s_form_valid' % form_name
        if hasattr(self, form_valid_method):
            return getattr(self, form_valid_method)(forms[form_name])
        else:
            return HttpResponseRedirect(self.get_success_url(form_name))
     
    def forms_invalid(self, forms):
        return self.render_to_response(self.get_context_data(forms=forms))
    
    def get_initial(self, form_name):
        initial_method = 'get_%s_initial' % form_name
        if hasattr(self, initial_method):
            return getattr(self, initial_method)()
        else:
            return self.initial.copy()
        
    def get_prefix(self, form_name):
        return self.prefixes.get(form_name, self.prefix)
        
    def get_success_url(self, form_name=None):
        return self.success_urls.get(form_name, self.success_url)
    
    def _create_form(self, form_name, klass, bind_form):
        form_kwargs = self.get_form_kwargs(form_name, bind_form)
        form_create_method = 'create_%s_form' % form_name
        if hasattr(self, form_create_method):
            form = getattr(self, form_create_method)(**form_kwargs)
        else:
            form = klass(**form_kwargs)
        return form
           
    def _bind_form_data(self):
        if self.request.method in ('POST', 'PUT'):
            return{'data': self.request.POST,
                   'files': self.request.FILES,}
        return {}


class ProcessMultipleFormsView(ProcessFormView):
    
    def get(self, request, *args, **kwargs):
        form_classes = self.get_form_classes()
        forms = self.get_forms(form_classes)
        return self.render_to_response(self.get_context_data(forms=forms))
     
    def post(self, request, *args, **kwargs):
        form_classes = self.get_form_classes()
        form_name = request.POST.get('action')
        if self._individual_exists(form_name):
            return self._process_individual_form(form_name, form_classes)
        elif self._group_exists(form_name):
            return self._process_grouped_forms(form_name, form_classes)
        else:
            return self._process_all_forms(form_classes)
        
    def _individual_exists(self, form_name):
        return form_name in self.form_classes
    
    def _group_exists(self, group_name):
        return group_name in self.grouped_forms
              
    def _process_individual_form(self, form_name, form_classes):
        forms = self.get_forms(form_classes, (form_name,))
        form = forms.get(form_name)
        if not form:
            return HttpResponseForbidden()
        elif form.is_valid():
            return self.forms_valid(forms, form_name)
        else:
            return self.forms_invalid(forms)
        
    def _process_grouped_forms(self, group_name, form_classes):
        form_names = self.grouped_forms[group_name]
        forms = self.get_forms(form_classes, form_names)
        if all([forms.get(form_name).is_valid() for form_name in form_names.values()]):
            return self.forms_valid(forms)
        else:
            return self.forms_invalid(forms)
        
    def _process_all_forms(self, form_classes):
        forms = self.get_forms(form_classes, None, True)
        if all([form.is_valid() for form in forms.values()]):
            return self.forms_valid(forms)
        else:
            return self.forms_invalid(forms)
 
 
class BaseMultipleFormsView(MultiFormMixin, ProcessMultipleFormsView):
    """
    A base view for displaying several forms.
    """
 
class MultiFormsView(TemplateResponseMixin, BaseMultipleFormsView):
    """
    A view for displaying several forms, and rendering a template response.
    """

@caiopaje could you add a screenshot of your view?
From the error, you didn't exposed the field "atividade" field from your forms or you don't have such field in your model "NovaAtividade"

Hi guys, could you help me with a trial to use your approach for my needs?

https://stackoverflow.com/questions/76357340/cannot-proceed-with-multiform-view-in-class-based-views