I am trying to implement a Map-Structured rule to read/write a Fixed Length text file, however I am unable to get the expected output .

Do you have any other post which explains the Map-Structured rule other than the below. Or is there any OOTB method available to generate a Fixed length text file. Because I want to create a reusable generic activity which can be used across my application for creating a Fixed length file.

https://pdn.pega.com/how-process-structured-streams-using-map-structured-rule