Form errors in ListFormsetView created by adding methods to a ListView.

[VISHESH MANGLA]

Hello, 

I am consistently getting this bizarre error and formset_invalid is getting triggered.

I just tried to make a generic ListFormSetView.

[11/Jun/2021 12:48:24] "GET /adminuser/print-report/?page=1 HTTP/1.1" 200 5244
[{'PAN_ID': ['User with this Pan ID already exists.']}]
[11/Jun/2021 12:59:29] "POST /adminuser/print-report/?page=2 HTTP/1.1" 200 5250

In my model the USERNAME_FIELD  is PAN_ID.

Webpage looks like this

https://ibb.co/CHT4nKB

Code:

class PrintStatementView(ListFormSetView):

    paginate_by = 1

    model = User

    form_class = PrintReportModelForm

    template_name = "adminuser/printstatement.html"

    context_formset_name = "formset"

    ordering = ("PAN_ID",)

    def get_factory_object(self):

        return modelformset_factory(

            self.model,

            form=self.form_class,

            extra=0,

        )

    def formset_valid(self, formset):

        self.request.session.setdefault("to_download", [])

        self.request.session["to_download"][self.kwargs["page"]] = [

            x["PAN_ID"]

            for x in formset.cleaned_data

            if x["print_report_check"]

        ]

        return HttpResponseRedirect(

            f"{reverse('print-report')}?page={self.kwargs['page']}"

        )

    def get_success_url(self):

        return reverse("adminuser:trading-window-list")

class ListFormSetView(ListView):

    def get_factory_object(self):

        return NotImplementedError(" Implement yourself ")

    def get_context_data(self, *, object_list=None, **kwargs):

        context_formset_name = (

            getattr(self, "context_formset_name", None) or "formset"

        )

        context_data = super().get_context_data(**kwargs)

        object_list = context_data["object_list"]

        context_data[context_formset_name] = self.get_factory_object()(

            queryset=object_list, initial=self.get_initial(object_list)

        )

        return context_data

    def get_form_kwargs(self):

        context_data = super().get_context_data()

        object_list = context_data["object_list"]

        kwargs = {

            "initial": self.get_initial(object_list),

            "queryset": object_list,

        }

        if self.request.method in ("POST", "PUT"):

            kwargs.update(

                {

                    "data": self.request.POST,

                    "files": self.request.FILES,

                }

            )

        return kwargs

    def get_initial(self, queryset=[]):

        """ Generate the initial data for the paginated queryset for the current page"""

        try:

            return self.initial

        except AttributeError:

            data = serializers.serialize("json", queryset)

            data = json.loads(data)

            return data

    def post(self, request, *args, **kwargs):

        self.object_list = self.get_queryset()

        formset = self.get_factory_object()(**self.get_form_kwargs())

        if formset.is_valid():

            return self.formset_valid(formset)

        else:

            return self.formset_invalid(formset)

    def formset_valid(self, formset):

        return HttpResponseRedirect(self.get_success_url())

    def formset_invalid(self, formset):

        print(formset.errors)

        return self.render_to_response(self.get_context_data(formset=formset))

[Lalit Suthar]

possibly you are requesting with the same pan id again

[VISHESH MANGLA]

Sorry , I should have posted the template

well, the error is,  hmm,

suppose you are at  page 1  , now you clicked next and you got to page 2 and the `post` method is hit. It will get page number as 2. But for  formset , the initial data will have to be compared with  page "1" s data not "2". In the current scenario ,the initial_data  was the page2's but the data that was posted was for page 1. So you see the problem? It took me quite long to understand this.

 

 

{% extends 'adminuser/portal.html' %} 

{% block main-content %}

{% load my_extra_filters %}

 {% if messages %}

{% for message in messages %}

<div class="alert alert-success" role="alert">{{ message }}</div>

{% endfor %}

 {% endif %}

<form method="post" >

  {% csrf_token %}

  {{ formset.management_form }}

  <table class="table">

    <thead>

      <tr>

        <th scope="col">Name</th>

        <th scope="col">Pan ID</th>

        <th scope="col">Print Report?</th>

      </tr>

    </thead>

    <tbody>

      {% for user_form in formset %}

        {% for user_data in object_list %}

          {% if forloop.counter0 == forloop.parentloop.counter0 %}

              <tr>

                <td>{{user_data.get_full_name.}}</td>

                <td>{{user_data.PAN_ID}}</td>

                {{user_form.PAN_ID}}

                

                <td>{{user_form.print_report_check}}</td>

              </tr>

      

          {% endif %}

        {% endfor %}

    

      {% endfor %}

    </tbody> 

  </table>

<div class="pagination">

    <span class="step-links">

        {% if page_obj.has_previous %}

            <button class="btn btn-dark"  formaction="?page=1">&laquo; first</button>

            <button class="btn btn-dark" formaction="?page={{ page_obj.previous_page_number }}">previous</button>

        {% endif %}

        <span class="current">

            Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}.

        </span>

        {% if page_obj.has_next %}

            <button class="btn btn-dark" formaction="?page={{ page_obj.next_page_number }}">next</button>

            <button class="btn btn-dark" formaction="?page={{ page_obj.paginator.num_pages }}">last &raquo;</button>

        {% endif %}

    </span>

</div>

  <button class="btn btn-dark">Print</button>

</form>

{% endblock main-content%}