Fix registration count without ruining performance

shiftregister/app/models.py

@@ -57,12 +57,16 @@ class Shift(models.Model):
         return (self.start_at <= timezone.now()) and (not self.has_ended())
 
     def registration_count(self):
-        return self.shiftregistration_set.filter(
-            state__in=[
-                ShiftRegistration.RegState.REGISTERED,
-                ShiftRegistration.RegState.CHECKED_IN,
-            ]
-        ).count()
+        return (
+            self.reg_count
+            if hasattr(self, "reg_count")
+            else self.shiftregistration_set.filter(
+                state__in=[
+                    ShiftRegistration.RegState.REGISTERED,
+                    ShiftRegistration.RegState.CHECKED_IN,
+                ]
+            ).count()
+        )
 
 
 class Helper(models.Model):

shiftregister/app/templates/partials/shift_listitem.html

@@ -9,7 +9,7 @@
             <strong>Ort:</strong> {{ shift.room.name }}<br>
             <strong>Beginn:</strong> {{ shift.start_at }}<br>
             <strong>Dauer:</strong> {{ shift.duration|duration }}<br>
-            <strong>Belegung:</strong> {{ shift.reg_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
+            <strong>Belegung:</strong> {{ shift.registration_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
         </div>
         <div class="buttons is-right">
             <a class="button is-info is-small mr-0" href="{% url 'shift' shift.id %}">Details</a>

shiftregister/app/templates/shift.html

@@ -21,7 +21,7 @@
             <strong>Beginn:</strong> {{ shift.start_at }}<br>
             <strong>Dauer:</strong> {{ shift.duration|duration }}<br>
             <strong>Treffpunkt:</strong> {{ shift.room.meeting_location|linebreaksbr }}<br>
-            <strong>Belegung:</strong> {{ shift.reg_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
+            <strong>Belegung:</strong> {{ shift.registration_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
         </p>
         {% if shift.room.description %}
             <div class="description">

shiftregister/team/templates/partials/shift_box.html

@@ -6,7 +6,7 @@
         <strong>Ort:</strong> {{ shift.room.name }}<br>
         <strong>Beginn:</strong> {{ shift.start_at }}<br>
         <strong>Dauer:</strong> {{ shift.duration }}<br>
-        <strong>Belegung:</strong> {{ shift.reg_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
+        <strong>Belegung:</strong> {{ shift.registration_count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
     </div>
     <div class="is-flex is-justify-content-end">
         <a class="button is-info is-small" href="{% url 'team:shift' shift.id %}">Details</a>