wagtail/wagtail/contrib/forms/panels.py

from django.utils.functional import cached_property
from django.utils.translation import gettext as _

from wagtail.admin.panels import Panel


class FormSubmissionsPanel(Panel):
    def on_model_bound(self):
        if not self.heading:
            self.heading = _("%(model_name)s submissions") % {
                "model_name": self.model.get_verbose_name()
            }

    class BoundPanel(Panel.BoundPanel):
        template_name = "wagtailforms/panels/form_responses_panel.html"

        @cached_property
        def submissions(self):
            form_page_model = self.panel.model
            form_submissions_model = form_page_model().get_submission_class()
            return form_submissions_model.objects.filter(page=self.instance)

        @cached_property
        def submission_count(self):
            return self.submissions.count()

        def is_shown(self):
            return self.submission_count

        def get_context_data(self, parent_context=None):
            context = super().get_context_data(parent_context)

            context.update(
                {
                    "submission_count": self.submission_count,
                    "last_submit_time": self.submissions.order_by("submit_time")
                    .last()
                    .submit_time,
                }
            )

            return context