HOOK METHODS in View Controller:
Hook Methods are standard SAP methods in web dynpro programming which are automatically created by SAP to control the execution flow of a web dynpro application.
These methods are similar to events in SAP reports (classical reports).
Method for initialization logic, this is the first method displayed before view is displayed. This method is used to initialize variables, default data etc.
This method is used to modify view dynamically based on user actions, this is used for dynamic programming.
This method is used to validate user input.
Method for all common logic used in all methods or event handler methods.
This method is used for clearing/refreshing nodes, attributes etc.