wscalls: preview unflattened payload (#66916)

wcs/root.py

@@ -337,9 +337,9 @@ class RootDirectory(Directory):
             dump = json.dumps(unflatten_keys(payload), ensure_ascii=False, indent=2)
             r += htmltext('<pre>%s</pre>') % dump.replace('"{{', '{{').replace('}}"', '}}')
         except UnflattenKeysException as e:
-            r += htmltext('<div class="errornotice"><p>%s</p><p>%s%s</p></div>') % (
-                _('Unable to unflatten payload.'),
-                _('Error message: '),
+            r += htmltext('<div class="errornotice"><p>%s</p><p>%s<code>%s</code></p></div>') % (
+                _('Unable to generate payload.'),
+                _('Following error occured: '),
                 e,
             )
         r += htmltext('</div>')

wcs/wscalls.py

@@ -107,8 +107,8 @@ def unflatten_keys(d):
             assert isinstance(d, list)
             if len(d) < key:
                 raise UnflattenKeysException(
-                    _('incomplete array before %s in %s') % ('/'.join([str(x) for x in path[: i + 1]])),
-                    orig_key,
+                    _('incomplete array before %s in %s')
+                    % (('/'.join([str(x) for x in path[: i + 1]])), orig_key)
                 )
             if len(d) == key:
                 d.append(new)