Here is a sample mapping file, containing a value, an equal sign and a replacing value:
EUR=Europe
AFR=Africa
USA=United States
and so on - you get it.
If you have a column in your data named "region" and it contains the value "AFR", then you can use an action to replace all values in the column with their relevant mapping value.
All you have to do is to define an action, define the field in the data stream (data row) and define the file where the mappings are stored. The file is cached on first usage for optimal performance.
As you may know, actions in the ruleengine are fired based on the results of a rulegroup. A rulegroup contains one or more business rules that belong together and form a certain logic. When the rulegroup passes all rules (checks) or fails all or both an action (or multiple ones) may be fired.
The ruleengine, documentation, Nifi processor, Pentaho plugin and samples are available at:
http://github.com/uwegeercken
Give it a try and as always please send me some feedback.
Carpe Diem