[BUG] NoUpdate.is_no_update can't handle ndarray #2173
Description
Describe your context
currently running project using dash for data display, callbacks pass ndarrays of certain sections of data to view
dash 2.6.0 dash-bootstrap-components 1.2.0 dash-core-components 2.0.0 dash-daq 0.5.0 dash-extensions 0.1.5 dash-html-components 2.0.0 dash-table 5.0.0 Describe the bug
if callback passes an ndarray, NoUpdate.is_no_update on line 441 of _callback.py raises a ValueError, this issue was not seen in previous versions.
[2022-07-31 16:27:03,570] ERROR in app: Exception on /_dash-update-component [POST] Traceback (most recent call last): File "...\venv\lib\site-packages\flask\app.py", line 2077, in wsgi_app response = self.full_dispatch_request() File "...\venv\lib\site-packages\flask\app.py", line 1525, in full_dispatch_request rv = self.handle_user_exception(e) File "...\venv\lib\site-packages\flask\app.py", line 1523, in full_dispatch_request rv = self.dispatch_request() File "...\venv\lib\site-packages\flask\app.py", line 1509, in dispatch_request return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args) File "...\venv\lib\site-packages\dash\dash.py", line 1260, in dispatch ctx.run( File "...\venv\lib\site-packages\dash\_callback.py", line 441, in add_context if NoUpdate.is_no_update(output_value): ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all() Workaround for this is wrapping ndarray with list, like this:
return [myndArr]