raise better error message if trying to make a callback with an incomplete set of inputs

Question

raise better error message if trying to make a callback with an incomplete set of inputs

chriddyp opened this issue 6 years ago · 3 comments

chriddyp commented 6 years ago

Right now, we just get a "Cannot concat on undefined".

Answer 1 · 2018-07-19T02:11:18.000Z

I think this is a duplicate of #57 which has a temporary fix in #60 and should also be addressed in plotly/dash#292

Answer 2 · 2018-08-14T00:07:39.000Z

I think this may have been fixed when #60 was merged. From experimenting it seems that:

inputs = [] -> callback is never fired
inputs has length less than the number of arguments -> a server error is thrown
inputs has proper length, but one of the ids does not exist in the DOM at the time the callback is fired -> an informative front-end exception is thrown due to #60

Is there an example of a dash app producing that error?

Answer 3 · 2019-05-22T15:43:35.000Z

I'm assuming this has been addressed by some of our recent devtools improvements, but @chriddyp if there's still a problem here please open a new issue in dash.