Fewer requests with shotgunable reventes

bda.views.revente_shotgun:
- 2 requests instead of ~#spectacles requests

bda/views.py

@@ -15,7 +15,7 @@ from django.contrib.auth.decorators import login_required
 from django.contrib import messages
 from django.db import transaction
 from django.core import serializers
-from django.db.models import Count, Q
+from django.db.models import Count, Q, Prefetch
 from django.forms.models import inlineformset_factory
 from django.http import (
     HttpResponseBadRequest, HttpResponseRedirect, JsonResponse
@@ -560,13 +560,13 @@ def buy_revente(request, spectacle_id):
 
     # Si l'utilisateur veut racheter une place qu'il est en train de revendre,
     # on supprime la revente en question.
-    if reventes.filter(seller=participant).exists():
-        revente = reventes.filter(seller=participant)[0]
-        revente.delete()
+    own_reventes = reventes.filter(seller=participant)
+    if len(own_reventes) > 0:
+        own_reventes[0].delete()
         return HttpResponseRedirect(reverse("bda-shotgun",
                                             args=[tirage.id]))
 
-    reventes_shotgun = list(reventes.filter(shotgun=True).all())
+    reventes_shotgun = reventes.filter(shotgun=True)
 
     if not reventes_shotgun:
         return render(request, "bda-no-revente.html", {})
@@ -598,16 +598,21 @@ def buy_revente(request, spectacle_id):
 @login_required
 def revente_shotgun(request, tirage_id):
     tirage = get_object_or_404(Tirage, id=tirage_id)
-    spectacles = tirage.spectacle_set.filter(
-        date__gte=timezone.now())
-    shotgun = []
-    for spectacle in spectacles:
-        reventes = SpectacleRevente.objects.filter(
-            attribution__spectacle=spectacle,
-            shotgun=True,
-            soldTo__isnull=True)
-        if reventes.exists():
-            shotgun.append(spectacle)
+    spectacles = (
+        tirage.spectacle_set
+        .filter(date__gte=timezone.now())
+        .select_related('location')
+        .prefetch_related(Prefetch(
+            'attribues',
+            queryset=(
+                Attribution.objects
+                .filter(revente__shotgun=True,
+                        revente__soldTo__isnull=True)
+            ),
+            to_attr='shotguns',
+        ))
+    )
+    shotgun = [sp for sp in spectacles if len(sp.shotguns) > 0]
 
     return render(request, "bda-shotgun.html",
                   {"shotgun": shotgun})