2 ways of doing this:You make the rest of the fields wrapped in a
subform and then set visibility of the subform so that only when field
is non-empty the subform is visible, by setting property :
Subform.presence="visible".You can set the access levels of the fields
initially to protected and later only in case field is non-null enable
users to edit the fields, using the access property:
TextField.access="open"; //"open" to unprotect the fields