Refactor case prior display: extract prior card markup into a separate partial for improved maintainability and readability

atlas/views.py

@@ -2758,33 +2758,71 @@ def collection_take_start(request, pk, cid=None, passcode=None):
 @user_is_collection_author_or_atlas_editor
 def collection_case_priors(request, exam_id, case_id):
     case_detail = CaseDetail.objects.get(case=case_id, collection=exam_id)
+    collection = case_detail.collection
 
     if request.htmx:
+        # Ensure we can render the updated single-card partial and return it so HTMX
+        # can swap the card on the client side.
         if "remove" in request.POST:
-            p = CasePrior.objects.get(
-                case_detail=case_detail, prior_case=request.POST["remove"]
+            prior_pk = request.POST["remove"]
+            try:
+                p = CasePrior.objects.get(case_detail=case_detail, prior_case=prior_pk)
+                p.delete()
+            except CasePrior.DoesNotExist:
+                # Already removed; continue and render the not-added card
+                pass
+
+            prior_case = Case.objects.get(pk=prior_pk)
+            added = False
+            relation = ""
+            visibility = "AL"
+
+            html = render_to_string(
+                "atlas/partials/_prior_card.html",
+                {
+                    "case": prior_case,
+                    "added": added,
+                    "relation": relation,
+                    "visibility": visibility,
+                    "case_detail": case_detail,
+                    "collection": collection,
+                },
+                request=request,
             )
-            p.delete()
-            return HttpResponse(f"Case removed")
+            return HttpResponse(html)
         elif "prior_case_id" in request.POST:
-            if not request.POST["relation"]:
+            if not request.POST.get("relation"):
                 return HttpResponse(
-                    "You need to enter text to describe the relationship between the cases"
+                    "You need to enter text to describe the relationship between the cases",
+                    status=400,
                 )
             prior_case = Case.objects.get(pk=request.POST["prior_case_id"])
             p, created = CasePrior.objects.get_or_create(
                 case_detail=case_detail, prior_case=prior_case
             )
-            p.relation_text = request.POST["relation"]
-
-            p.prior_visibility = request.POST["prior_visibility"]
-
+            p.relation_text = request.POST.get("relation", "")
+            p.prior_visibility = request.POST.get("prior_visibility", "AL")
             p.save()
 
-            return HttpResponse(f"Case added")
+            added = True
+            relation = p.relation_text
+            visibility = p.prior_visibility
+
+            html = render_to_string(
+                "atlas/partials/_prior_card.html",
+                {
+                    "case": prior_case,
+                    "added": added,
+                    "relation": relation,
+                    "visibility": visibility,
+                    "case_detail": case_detail,
+                    "collection": collection,
+                },
+                request=request,
+            )
+            return HttpResponse(html)
         else:
-            return HttpResponse("False")
-            raise Http404()
+            return HttpResponse("False", status=400)
 
     collection = case_detail.collection