Handle exceptions when retrieving account balances

src/gnucash_web/__init__.py

@@ -54,6 +54,7 @@ def create_app(test_config=None):
     app.jinja_env.filters['full_account_names'] = jinja_utils.full_account_names
     app.jinja_env.filters['contrasplits'] = jinja_utils.contra_splits
     app.jinja_env.filters['nth'] = jinja_utils.nth
+    app.jinja_env.filters['safe_get_balance'] = jinja_utils.safe_get_balance
     app.jinja_env.globals['is_authenticated'] = auth.is_authenticated
 
     with (Path(__file__).parent / 'version.txt').open() as version:

src/gnucash_web/templates/account.j2

@@ -28,7 +28,7 @@
       <div class="list-group-item">
         <b>Total</b>
         <span class="float-end">
-          {{ account.get_balance() | money(account.commodity) }}
+          {{ account | safe_get_balance | money(account.commodity) }}
         </span>
       </div>
     </div>
@@ -54,7 +54,7 @@
           </a>
 
           <span class="float-end">
-            {{ account.get_balance() | money(account.commodity) }}
+            {{ account | safe_get_balance | money(account.commodity) }}
           </span>
         </div>
 

src/gnucash_web/utils/jinja.py

@@ -1,4 +1,5 @@
 """Utilities for templates."""
+import logging
 import re
 from urllib.parse import quote_plus
 from itertools import islice, accumulate
@@ -8,6 +9,7 @@
 from babel import numbers
 from markupsafe import Markup, escape
 from jinja2 import Environment, BaseLoader, pass_eval_context
+from piecash import GnucashException
 
 
 def safe_display_string(string):
@@ -59,6 +61,9 @@ def money(eval_ctx, amount, commodity):
     :returns: HTML snippet
 
     """
+    if amount is None:
+        return Markup('<span class="text-danger">Error</span>')
+
     if numbers.get_currency_symbol(commodity.mnemonic) != commodity.mnemonic:
         value = numbers.format_currency(amount, commodity.mnemonic)
     else:
@@ -132,3 +137,12 @@ def contra_splits(split):
 def nth(iterable, n, default=None):
     "Returns the nth item or a default value"
     return next(islice(iterable, n, None), default)
+
+
+def safe_get_balance(account):
+    """Get balance of account, but catch piecash exceptions."""
+    try:
+        return account.get_balance()
+    except GnucashException as e:
+        logging.warning(f"Failed to retrieve balance for account {account}: {e}")
+        return None