Fix add snapshot page

nummi/main/templates/main/snapshot.html

@@ -32,6 +32,7 @@
 	</div>
 </form>
 
+{% if categories %}
 <h2>Plot</h2>
 <div class="chart">
 	{% for cat in categories %}
@@ -83,6 +84,7 @@
 	</div>
 	{% endfor %}
 </div>
+{% endif %}
 
 {% if snapshot.transactions %}
 <h2>Transactions ({{ sum|pmvalue }} / {{ snapshot.diff|pmvalue }})</h2>

nummi/main/views.py

@@ -163,27 +163,28 @@ def snapshot(request, uuid=None):
             "form": _form,
         }
 
-    context["categories"] = (
+    if _snapshot.transactions:
-        _snapshot.transactions.values("category", "category__name", "category__icon")
+        context["categories"] = (
-        .annotate(
+            _snapshot.transactions.values("category", "category__name", "category__icon")
-            sum=models.Sum("value"),
+            .annotate(
-            sum_m=models.Sum("value", filter=models.Q(value__lt=0)),
+                sum=models.Sum("value"),
-            sum_p=models.Sum("value", filter=models.Q(value__gt=0)),
+                sum_m=models.Sum("value", filter=models.Q(value__lt=0)),
-        )
+                sum_p=models.Sum("value", filter=models.Q(value__gt=0)),
-        .order_by("-sum")
-    )
-    context["cat_lim"] = max(
-        map(
-            abs,
-            context["categories"]
-            .aggregate(
-                max=models.Max("sum_p"),
-                min=models.Min("sum_m"),
             )
-            .values(),
+            .order_by("-sum")
         )
-    )
+        context["cat_lim"] = max(
-    context["cat_lim_m"] = -context["cat_lim"]
+            map(
+                abs,
+                context["categories"]
+                .aggregate(
+                    max=models.Max("sum_p"),
+                    min=models.Min("sum_m"),
+                )
+                .values(),
+            )
+        )
+        context["cat_lim_m"] = -context["cat_lim"]
     return render(
         request,
         "main/snapshot.html",