The Data Modification service action enables modification of fields in a data message through the use of a function you define. This function can perform calculations using the field values contained in an incoming data message as input. Based on the results of the calculations, field values in incoming data messages can be modified and replaced with output from the calculations. The replaced field values will appear in the features that are created from the data messages in the tracking layer. The function is only run for data messages that meet the trigger criteria you define.
For example, imagine that you are tracking shipments from different distributors, and the weight of each shipment is included in a field in your data. You discover there is one distributor that enters the weight in kilograms, but all the other distributors enter the weight in pounds. A Data Modification service action can be used to convert the weight from kilograms to pounds for shipments originating from that distributor.
Defining Data Modification functions
All functions in the Data Modification Action Language must be defined using the Edit Function dialog box. This dialog box allows the user to create a function by typing it into a large text box. The user can also make changes to an existing function being used by a Data Modification action. Any function that is created or modified must be validated in the Edit Function dialog box before it can be used in a Data Modification action.
Functions are defined for the Data Modification service action using a programming language called Data Modification Action Language. The language is simple but has enough power to perform a large variety of processing tasks.