e.g. I've got a list of labels that the user can define, and a list of items they've ordered. If they don't have any custom labels there's no point in showing the drop down list for the label. However as soon as they add a custom label I want them to be able to select the label for one or more items.

show input.subform.field; gives an improper statement error.

show subform.field; gives an invalid task in subform action.

Finally I can't work out how to use a input.subform.field:ui.show option.

However the second one works in the form.load workflow.

I tried enabling and disabling too with the same result.