Resolve "update of appointment clears data from daily planning"

Closes #166 (closed)

smash/web/forms.py

@@ -241,11 +241,20 @@ class AppointmentEditForm(ModelForm):
 
     def save(self, commit=True):
         appointment = super(AppointmentEditForm, self).save(commit)
-        AppointmentTypeLink.objects.filter(appointment=appointment).delete()
+        appointment_type_links = AppointmentTypeLink.objects.filter(appointment=appointment).all()
+        appointment_types_from_links = []
         appointment_types = self.cleaned_data['appointment_types']
+        for appointment_type_link in appointment_type_links:
+            if appointment_type_link.appointment_type not in appointment_types:
+                # we delete appointment links for appointments types that have been removed
+                appointment_type_link.delete()
+            else:
+                appointment_types_from_links.append(appointment_type_link.appointment_type)
         for appointment_type in appointment_types:
-            appointment_type_link = AppointmentTypeLink(appointment=appointment, appointment_type=appointment_type)
-            appointment_type_link.save()
+            if appointment_type not in appointment_types_from_links:
+                # we create new appointment links for appointements types that have been added
+                appointment_type_link = AppointmentTypeLink(appointment=appointment, appointment_type=appointment_type)
+                appointment_type_link.save()
         return appointment