From 58ac291f9ffee4efa57f154f1f3e7172268a84c0 Mon Sep 17 00:00:00 2001
From: yshepilov <buggygm@gmail.com>
Date: Sat, 18 Mar 2023 16:08:44 +0100
Subject: [PATCH] #320 fixed missing observable notifications in case of an
 exception + fixed swallowing a websocket future exception

---
 src/model/script_config.py      |  1 -
 src/react/properties.py         | 16 +++++++++++-----
 src/web/script_config_socket.py | 11 +++++++++--
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/model/script_config.py b/src/model/script_config.py
index 507c493e..8f854db5 100644
--- a/src/model/script_config.py
+++ b/src/model/script_config.py
@@ -1,5 +1,4 @@
 import logging
-import logging
 import os
 from collections import OrderedDict
 from dataclasses import dataclass, field
diff --git a/src/react/properties.py b/src/react/properties.py
index acfe79c4..398447fd 100644
--- a/src/react/properties.py
+++ b/src/react/properties.py
@@ -1,11 +1,13 @@
+import logging
 from collections import UserList, UserDict
-
 from typing import Optional, Iterable as Iterable, Mapping as Mapping, TypeVar
 
 _T = TypeVar('_T')
 _KT = TypeVar('_KT')
 _VT = TypeVar('_VT')
 
+LOGGER = logging.getLogger('script_server.properties')
+
 
 class Property:
     def __init__(self, value=None):
@@ -152,9 +154,7 @@ def __setitem__(self, key: _KT, item: _VT) -> None:
 
         super().__setitem__(key, item)
 
-        if self._observers:
-            for observer in self._observers:
-                observer(key, old_value, item)
+        self._notify_observers(key, old_value, item)
 
     def __delitem__(self, key: _KT) -> None:
         old_value = self.get(key)
@@ -164,9 +164,15 @@ def __delitem__(self, key: _KT) -> None:
         if old_value is None:
             return
 
+        self._notify_observers(key, old_value, None)
+
+    def _notify_observers(self, key, old_value, new_value):
         if self._observers:
             for observer in self._observers:
-                observer(key, old_value, None)
+                try:
+                    observer(key, old_value, new_value)
+                except:
+                    LOGGER.exception('Failed to notify observer ' + repr(observer))
 
 
 def observable_fields(*fields):
diff --git a/src/web/script_config_socket.py b/src/web/script_config_socket.py
index c742405a..691a5058 100644
--- a/src/web/script_config_socket.py
+++ b/src/web/script_config_socket.py
@@ -70,13 +70,20 @@ def on_message(self, text):
             data = message.get('data')
 
             if type == 'parameterValue':
+                param = data.get('parameter')
                 set_parameter_func = functools.partial(
                     self._set_parameter_value,
-                    data.get('parameter'),
+                    param,
                     data.get('value'),
                     data.get('clientStateVersion'))
 
-                self._start_task(set_parameter_func)
+                def handle_future_exception(result):
+                    if result.exception():
+                        LOGGER.exception(f'Failed to set parameter {param} value', exc_info=result.exception())
+
+                future = self._start_task(set_parameter_func)
+                future.add_done_callback(handle_future_exception)
+
                 return
             elif type == 'reloadModelValues':
                 parameter_values = data.get('parameterValues')