The next step will be to attach a Pentaho PDI Transformation to a project. The web app will check the transformation for rule engine steps and extract the field names from the transformation. This allows the user of the tool to choose from a list of fields instead of typing them in by hand. Also the type of the individual fields does not need to be specified, as its extracted from the transformation.
I have started with the implementation and hope to have it finished by mid to end of January.