I am trying to create a script tool, and I'd like to use the Field Mappings data type for my 2nd parameter (1st parameter is a Feature Class, Table, etc.). It seems like this type of parameter should have the Obtained from property enabled, but I cannot find a data type, for use with the 1st parameter, that enables the Obtained from property.
While trying to troubleshoot the issue, I place code in the updateParameters validation function that logs debug messages to a text file. When I try to find the data type of the Field Mappings parameter, using the type() function with self.params.value or self.params, I get: <type 'NoneType'>.
Can someone please explain how to use the Field Mapping data type with a script tool? Specifically, I'd like to know how to populate the control associated with the Field Mappings data type.