Using transformation language to define source data

When data is being mapped from the input to the output, TML allows the user to specify how the source data should be handled. Specifically, TML allows the user to specify whether the data path for the source should be processed iteratively (i.e. for each occurrence) or whether the data path should be processed only once. This is to handle single parent-multiple child structures, such as one header, many lines.

Generally, where a field in the input represents a single data value, this data should be processed only once. When the source specifies a containing record (e.g. a header contains lines), the source should be processed iteratively (i.e. in a for-each loop).