Make CheckNeedAppointment use simpler view pattern

Author: Themitchell

features/check_need_appointment.feature

@@ -27,4 +27,10 @@ Feature: Check if you need an appointment page
     When I check "No, I can continue online" and submit
     Then I am on "/height"
 
+  Scenario: Checking responses and changing them
+    Given I am logged in
+    When I go to "/check-if-you-need-an-appointment"
+    And I check "No, I can continue online" and submit
+    When I click "Back"
+    Then I see "No, I can continue online" selected
 

lung_cancer_screening/questions/views/check_need_appointment.py

@@ -1,47 +1,21 @@
-from django.shortcuts import render, redirect
-from django.urls import reverse
-from django.contrib.auth.mixins import LoginRequiredMixin
-from django.views import View
+from django.urls import reverse, reverse_lazy
 
-from .mixins.ensure_response_set import EnsureResponseSet
+from .question_base_view import QuestionBaseView
 from ..forms.check_need_appointment_form import CheckNeedAppointmentForm
-from ..models.check_need_appointment_response import CheckNeedAppointmentResponse
+from ..models.check_need_appointment_response import (
+    CheckNeedAppointmentResponse
+)
 
-class CheckNeedAppointmentView(LoginRequiredMixin, EnsureResponseSet, View):
-    def get(self, request):
-        response, _ = CheckNeedAppointmentResponse.objects.get_or_build(
-            response_set=request.response_set
-        )
 
-        return render_template(request, CheckNeedAppointmentForm(instance=response))
+class CheckNeedAppointmentView(QuestionBaseView):
+    template_name = "check_need_appointment.jinja"
+    form_class = CheckNeedAppointmentForm
+    model = CheckNeedAppointmentResponse
+    success_url = reverse_lazy("questions:height")
+    back_link_url = reverse_lazy("questions:date_of_birth")
 
-    def post(self, request):
-        response, _ = CheckNeedAppointmentResponse.objects.get_or_build(
-            response_set=request.response_set
-        )
-        form = CheckNeedAppointmentForm(
-            instance=response,
-            data=request.POST
-        )
-
-        if form.is_valid():
-            response.value = form.cleaned_data["value"]
-            response.save()
-
-            if form.cleaned_data["value"] :
-                return redirect(reverse("questions:book_an_appointment"))
-            else :
-                return redirect(reverse("questions:height"))
+    def get_success_url(self):
+        if self.object.value:
+            return reverse("questions:book_an_appointment")
         else:
-            return render_template(request, form, 422)
-
-def render_template(request, form, status=200):
-    return render(
-        request,
-        "check_need_appointment.jinja",
-        {
-            "form": form,
-            "back_link_url": reverse("questions:date_of_birth")
-        },
-        status=status
-    )
+            return super().get_success_url()