Django Select2: How to write a auto select dropdown form with django select2

[abhishek-ntt]

Hi, I'm writing a form @applegrew

forms/invoices.py

from django import forms
from django_select2.forms import ModelSelect2Widget

class CreditNoteFilterForm(forms.Form):
    credit_note_id = LimitedIntegerField(label="Credit Note ID",
                                         required=False, help_text="CN")
    customer = forms.ChoiceField(
                                 label="Choose customer", required=False,
                                 widget=ModelSelect2Widget(model=Customer,
                                        queryset = Customer.objects.all().exclude(is_active=False),
                                        search_fields = ["customer_name__istartswith",
                                                         "description__istartswith",
                                                         "user__first_name__istartswith",
                                                         "user__last_name__istartswith",
                                                         ]),
    )

template - templates/invoice/list.html

            {% if filter_form %}
                <div id="toolbar" class="search-form">
                    <form method="get" action="" id="changelist-search" class="changelist-search">
                        <table>
                            {{ filter_form.as_table }}
                            <tr>
                                <td></td>
                                <td>
                                    <input name="form_search_button" type="submit" value="Filter">
                                    {% block new_object_link %}
                                        <a class="link" href="{% url 'new_invoice' %}">New invoice</a>
                                    {% endblock new_object_link %}
                                </td>
                            </tr>
                        </table>
                    </form>
                </div>
            {% endif %}

and a class based view
views/invoices/listings.py

class BaseInvoiceLikeListView(ListView):

    def get_context_data(self, **kwargs):
        context = super(BaseInvoiceLikeListView, self).get_context_data(**kwargs)
        order_by_query, field, direction = get_order_by_from_request(
            self.request, self.columns)
        context["title"] = self.title
        context["sorting"] = field
        context["sorting_direction"] = direction
        context["columns"] = self.columns

    def get_filter_form(self):
        if not hasattr(self, "filter_form"):
            request = self.request
            self.filter_form = self.filter_form_class(request.GET)
            self.valid_filter_form = self.filter_form.is_valid()
        return self.valid_filter_form, self.filter_form

    def filter_with_form(self, qs):
        valid, form = self.get_filter_form()
        if valid:
            pk = form.cleaned_data.get(self.filter_key)
            customer = form.cleaned_data.get("customer")
            if pk:
                qs = qs.filter(pk=pk)
            if customer:
                qs = qs.filter(customer__id=customer.id)
        return qs

    def get_queryset(self):
        qs = super(BaseInvoiceLikeListView, self).get_queryset()
        qs = self.filter_with_form(qs)
        qs = self.sort_orders_queryset(qs)
        return qs

Application is running and we can see the Customer dropdown box and if we enter 2 letters it will start displaying the customers with those letters and once we select the customer and click on submit button, it is showing the error as Select a valid choice. 814 is not one of the available choices. But it is a valid customer id and there is a database record and after submit, the selected option is not selected in the form.

[Johannes Maron]

Hi @abhishek-ntt,

thanks for reaching out. I believe you are seeing this validation error, because you didn't pass any choices to your forms.ChoiceField. So even if the widget shows choices, the Django's form validation will think they are not valid. I would advise you to use a forms.ModelChoiceField and also pass the same queryset, that you pass to the widget queryset=Customer.objects.all().exclude(is_active=False).

I hope that solves your problem. If not, please reach out any time.

Best
-Joe