Added the "default" filter to reduce the amount of logic in the templates, which differs from the Jinja2 "default" filter in that it looks for None instead of undefined values.

src/accounting/templates/accounting/report/ledger.html

@@ -163,9 +163,9 @@ First written: 2023/3/5
   {% for item in list %}
     <tr {% if item.transaction is not none %} class="accounting-clickable accounting-table-row-link" data-href="{{ url_for("accounting.transaction.detail", txn=item.transaction)|accounting_append_next }}" {% endif %}>
       <td>{{ item.date|accounting_format_date }}</td>
-      <td>{{ "" if item.summary is none else item.summary }}</td>
-      <td class="accounting-amount">{{ "" if item.debit is none else item.debit|accounting_format_amount }}</td>
-      <td class="accounting-amount">{{ "" if item.credit is none else item.credit|accounting_format_amount }}</td>
+      <td>{{ item.summary|accounting_default }}</td>
+      <td class="accounting-amount">{{ item.debit|accounting_format_amount|accounting_default }}</td>
+      <td class="accounting-amount">{{ item.credit|accounting_format_amount|accounting_default }}</td>
       <td class="accounting-amount">{{ item.balance|accounting_format_amount }}</td>
     </tr>
   {% endfor %}