manager: add error when deleting an EventType linked to an Agenda (#85974)

chrono/manager/views.py

@@ -44,6 +44,7 @@ from django.utils.encoding import force_str
 from django.utils.formats import date_format
 from django.utils.functional import cached_property
 from django.utils.html import format_html
+from django.utils.safestring import SafeString
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext
 from django.views.generic import (
@@ -884,6 +885,41 @@ class EventsTypeDeleteView(DeleteView):
             raise PermissionDenied()
         return super().dispatch(request, *args, **kwargs)
 
+    def can_be_deleted(self):
+        return self.get_object().agendas.count() == 0
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        if self.can_be_deleted():
+            return ctx
+
+        obj = self.get_object()
+        ctx['cannot_delete'] = True
+
+        title = '<h3>%(title)s</h3>' % {
+            'title': _('Cannot delete event type "%(event_type_name)s"') % {'event_type_name': obj}
+        }
+        msg = _('Following agendas are style using this event type :')
+        lst = '<ul><li>%(agendas)s</li></ul>' % {
+            'agendas': '</li><li>'.join(
+                [
+                    '<a href="%s">%s</a>'
+                    % (reverse('chrono-manager-agenda-view', kwargs={'pk': agenda.pk}), agenda)
+                    for agenda in obj.agendas.all()
+                ]
+            )
+        }
+        ctx['cannot_delete_msg'] = SafeString(
+            '%(title)s %(msg)s %(agendas)s' % {'title': title, 'msg': msg, 'agendas': lst}
+        )
+
+        return ctx
+
+    def post(self, *args, **kwargs):
+        if self.can_be_deleted():
+            return super().post(*args, **kwargs)
+        raise PermissionDenied()
+
     def get_success_url(self):
         return reverse('chrono-manager-events-type-list')
 

tests/manager/test_events_type.py

@@ -164,10 +164,7 @@ def test_delete_events_type(app, admin_user):
 
 def test_delete_referenced_events_type(app):
     events_type = EventsType.objects.create(label='Foobar')
-    events_type.save()
-
-    agenda = Agenda(label='Foo Bar', events_type=events_type)
-    agenda.save()
+    agenda = Agenda.objects.create(label='Foo Bar', events_type=events_type)
 
     events_type.delete()
 
@@ -176,6 +173,34 @@ def test_delete_referenced_events_type(app):
     assert agenda.events_type is None
 
 
+def test_delete_referenced_events_type_error(app, admin_user):
+    events_type = EventsType.objects.create(label='Foobar')
+    agenda = Agenda.objects.create(label='Foo Bar', events_type=events_type)
+
+    app = login(app)
+
+    resp = app.get('/manage/events-types/', status=200)
+    resp = resp.click(href='/manage/events-type/%s/delete/' % events_type.pk)
+
+    resp.form.submit(status=403)
+
+    assert EventsType.objects.get(pk=events_type.pk)
+    assert 'Cannot delete event type "' in resp
+    assert '<a href="/manage/agendas/%s/">%s</a>' % (agenda.pk, agenda) in resp
+
+    agenda.delete()
+
+    # Now deletion should be OK
+    resp = app.get('/manage/events-types/', status=200)
+    resp = resp.click(href='/manage/events-type/%s/delete/' % events_type.pk)
+
+    assert 'Cannot delete event type "' not in resp
+    assert '<a href="/manage/agendas/%s/">%s</a>' % (agenda.pk, agenda) not in resp
+
+    resp.form.submit()
+    assert EventsType.objects.exists() is False
+
+
 def test_delete_events_type_as_manager(app, manager_user):
     agenda = Agenda(label='Foo Bar')
     agenda.view_role = manager_user.groups.all()[0]