When doing the mapping for a very complex requirement, we often come across situations where just using the mapper to develop the complex logic is more troublesome than simply writing few lines of code using standard programming constructs. We may also simply want to use our preexisting code do some calculation or perform certain actions. In order to meet these requirements we have 5 powerful tools which are equivalent to programming tools :
Global Variables
Lookups
Functions
Classes
Prolog and Epilog Scripts
The details of all these tools and how to use them are explained below :
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