Faulty support for subscribing to all node events

[Daniel-J101]

I am trying to get websocket updates for attribute changes that happen on a node that I am following.
client.py's MatterClient offers this function:

    def subscribe_events(
        self,
        callback: Callable[[EventType, Any], None],
        event_filter: Optional[EventType] = None,
        node_filter: Optional[int] = None,
        attr_path_filter: Optional[str] = None,
    ) -> Callable[[], None]:

The issue arises as the callback is only provided with the EventType and the actual value changed. If I were to use the node filter on node 3, I would receive value updates without the knowledge of which attribute's value is changing.

However, in the underlying handling of event updates _handle_event_message, the necessary context is available yet stripped.

        if msg.event == EventType.ATTRIBUTE_UPDATED:
            # data is tuple[node_id, attribute_path, new_value]
            node_id, attribute_path, new_value = msg.data # <== All necessary context is available
            if self.logger.isEnabledFor(logging.DEBUG):
                self.logger.debug(
                    "Attribute updated: Node: %s - Attribute: %s - New value: %s",
                    node_id,
                    attribute_path,
                    new_value,
                )
            self._nodes[node_id].update_attribute(attribute_path, new_value)
            self._signal_event(
                EventType.ATTRIBUTE_UPDATED,
                data=new_value, # <== context is stripped from the tuple and only the value is returned for callback
                node_id=node_id,
                attribute_path=attribute_path,
            )
            return

The alternative would be manually looping through each node's attribute in order to get all updates for that node. Please let me know if there is a better way of doing what I am trying to accomplish, or if this function can be modified to include the necessary context.

[Apollon77]

The attributePath is the info about which attribute changes ... What else you need?

[odahoda]

I'm playing around with the client and just ran into the same issue.

But the issue isn't in _handle_event_message(), but in _signal_event(). That function does get all necessary context information, but when it calls the callback, it doesn't pass on the node_id and attribute_path:

python-matter-server/matter_server/client/client.py

Line 789 in c4e9f60

callback(event, data)