Don't cache tournaments/rounds for API views

Getting odd intermittent 404 errors, and which were Django HTML rather
than DRF JSON, so was either a wrong URL or the Tournament/Round not
getting found.

For that, the debate middleware will ignore API paths, and the
properties in the API mixins will not use cached values, returning DRF
404s.

tabbycat/api/mixins.py

@@ -1,18 +1,25 @@
 import operator
 
+from rest_framework.generics import get_object_or_404
 from rest_framework.permissions import IsAdminUser
 
-from tournaments.mixins import RoundFromUrlMixin, TournamentFromUrlMixin
+from tournaments.models import Round, Tournament
 
 from .permissions import APIEnabledPermission, IsAdminOrReadOnly, PublicIfReleasedPermission, PublicPreferencePermission
 
 
-class TournamentAPIMixin(TournamentFromUrlMixin):
+class TournamentAPIMixin:
     tournament_field = 'tournament'
 
     access_operator = operator.eq
     access_setting = True
 
+    @property
+    def tournament(self):
+        if not hasattr(self, "_tournament"):
+            self._tournament = get_object_or_404(Tournament, slug=self.kwargs['tournament_slug'])
+        return self._tournament
+
     def lookup_kwargs(self):
         return {self.tournament_field: self.tournament}
 
@@ -28,10 +35,16 @@ def get_serializer_context(self):
         return context
 
 
-class RoundAPIMixin(TournamentAPIMixin, RoundFromUrlMixin):
+class RoundAPIMixin(TournamentAPIMixin):
     tournament_field = 'round__tournament'
     round_field = 'round'
 
+    @property
+    def round(self):
+        if not hasattr(self, "_round"):
+            self._round = get_object_or_404(Round, tournament=self.tournament, seq=self.kwargs['round_seq'])
+        return self._round
+
     def perform_create(self, serializer):
         serializer.save(**{self.round_field: self.round})
 

tabbycat/utils/middleware.py

@@ -14,7 +14,7 @@ def __call__(self, request):
         return response
 
     def process_view(self, request, view_func, view_args, view_kwargs):
-        if 'tournament_slug' in view_kwargs:
+        if 'tournament_slug' in view_kwargs and request.path.split('/')[1] != 'api':
             cached_key = "%s_%s" % (view_kwargs['tournament_slug'], 'object')
             cached_tournament_object = cache.get(cached_key)