Reduce the number of database queries in the view.

home/forms.py

@@ -31,8 +31,8 @@ def make_choices(question: Question) -> list[tuple[str, str]]:
 
 
 class BaseSurveyForm(forms.Form):
-    def __init__(self, survey, user, *args, **kwargs):
-        self.survey = survey
+    def __init__(self, instance, user, *args, **kwargs):
+        self.survey = instance
         self.user = user if user.is_authenticated else None
         self.field_names = []
         self.questions = self.survey.questions.all().order_by("ordering")
@@ -161,11 +161,11 @@ def save(self):
 
 
 class UserSurveyResponseForm(BaseSurveyForm):
-    def __init__(self, user_survey_response, *args, **kwargs):
-        self.survey = user_survey_response.survey
-        self.user_survey_response = user_survey_response
+    def __init__(self, instance, *args, **kwargs):
+        self.survey = instance.survey
+        self.user_survey_response = instance
         super().__init__(
-            survey=self.survey, user=user_survey_response.user, *args, **kwargs
+            survey=self.survey, user=instance.user, *args, **kwargs
         )
         self._set_initial_data()
 

home/tests/test_user_survey_response_form_views.py

@@ -82,28 +82,40 @@ def setUpTestData(cls):
             name="Test Survey", description="This is a description of the survey!"
         )
         cls.user = UserFactory.create()
-        cls.question = QuestionFactory.create(
+        cls.question_1 = QuestionFactory.create(
             survey=cls.survey,
             label="How are you?",
         )
+        cls.question_2 = QuestionFactory.create(
+            survey=cls.survey,
+            label="What is your favourite food?",
+        )
         cls.survey_response = UserSurveyResponseFactory(
             survey=cls.survey, user=cls.user
         )
         UserQuestionResponseFactory(
             user_survey_response=cls.survey_response,
-            question=cls.question,
+            question=cls.question_1,
             value="Very good",
         )
+        UserQuestionResponseFactory(
+            user_survey_response=cls.survey_response,
+            question=cls.question_2,
+            value="Pizza",
+        )
         cls.url = reverse("user_survey_response", kwargs={"pk": cls.survey_response.id})
 
     def test_success_get(self):
         self.client.force_login(self.user)
-        response = self.client.get(self.url)
+        with self.assertNumQueries(2):
+            response = self.client.get(self.url)
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, "Test Survey")
         self.assertContains(response, "This is a description of the survey!")
         self.assertContains(response, "How are you?")
         self.assertContains(response, "Very good")
+        self.assertContains(response, "What is your favourite food?")
+        self.assertContains(response, "Pizza")
         self.assertNotContains(response, "Submit")
 
     def test_cannot_view_others_survey_response(self):

home/views.py

@@ -5,6 +5,7 @@
 from django.contrib import messages
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.contrib.auth.mixins import UserPassesTestMixin
+from django.db.models import Prefetch
 from django.shortcuts import render
 from django.urls import reverse_lazy
 from django.views.generic.detail import DetailView
@@ -16,6 +17,7 @@
 from .models import Event
 from .models import Session
 from .models import Survey
+from .models import UserQuestionResponse
 from .models import UserSurveyResponse
 
 
@@ -115,21 +117,19 @@ class CreateUserSurveyResponseFormView(
     template_name = "home/surveys/form.html"
 
     def test_func(self):
-        survey = self.get_object()
         user = self.request.user
         return (
             user.profile.email_confirmed
-            and not UserSurveyResponse.objects.filter(survey=survey, user=user).exists()
+            and not UserSurveyResponse.objects.filter(survey_id=self.kwargs.get(self.pk_url_kwarg), user=user).exists()
         )
 
     def get_form_kwargs(self):
         kwargs = super().get_form_kwargs()
-        kwargs["survey"] = self.get_object()
         kwargs["user"] = self.request.user
         return kwargs
 
     def get_context_data(self, **kwargs):
-        survey = self.get_object()
+        survey = self.object
         kwargs["title_page"] = survey.name
         kwargs["sub_title_page"] = survey.description
         return super().get_context_data(**kwargs)
@@ -154,18 +154,22 @@ class UserSurveyResponseView(
     success_url = reverse_lazy("session_list")
     template_name = "home/surveys/form.html"
 
-    def test_func(self):
-        survey_response = self.get_object()
-        user = self.request.user
-        return user == survey_response.user
+    def get_queryset(self):
+        return UserSurveyResponse.objects.select_related("survey").prefetch_related(
+            Prefetch(
+                "userquestionresponse_set",
+                queryset=UserQuestionResponse.objects.select_related("question"),
+            )
+        )
 
-    def get_form_kwargs(self):
-        kwargs = super().get_form_kwargs()
-        kwargs["user_survey_response"] = self.get_object()
-        return kwargs
+    def test_func(self):
+        return UserSurveyResponse.objects.filter(
+            user=self.request.user,
+            id=self.kwargs.get(self.pk_url_kwarg)
+        ).exists()
 
     def get_context_data(self, **kwargs):
-        survey = self.get_object().survey
+        survey = self.object.survey
         kwargs["title_page"] = survey.name
         kwargs["sub_title_page"] = survey.description
         kwargs["read_only"] = True