Is it possible to set a dropdown as mandatory?
Can you define required? Technically, you could abort the callback if it is empty.
I tried setting “clearable = False”, but it didn’t work. How could I abort the callback?
Something like this:
if value is None or value == '': return no_update
Or with your return, you could output to a modal that tells the user they need to fill in that field.
You could also make it so there is a submit button that isnt enabled until all the proper fields are filled in.