5.2 Extensibility in Backend Coding

This topic describes about the extensibility in backend coding.

Release specific code has to be written in the Hook Packages generated. Structure of a Maintenance and Transaction Call Form hook packages are almost the same.

Note:

though structure is almost the same ,arguments differ in transaction and maintenance call forms .Hence Transaction Call Form can be attached only with Transaction screen and similarly for Maintenance screens

Different functions available in the Hook Package of a Call Form are:

1. Skip Handler : Pr_Skip_Handler

   This can be used to skip the logic written in another release.

   Example: logic written in KERNEL release can be skipped in CLUSTER release

2. Fn Main

   This is called form the fn_main in main package.

3. Fn_pre_query
4. Fn_post_query

   Any specific logic while querying can be written in these functions. It is called from fn_query of the main package

5. Fn_pre_upload_db
6. Fn_post_upload_db

   Any logic while uploading data to tables can be written here.

7. Fn_pre_default_and_validate
8. Fn_post_default_and_validate

   Any release specific logic for defaulting and validation can be written here . It is called from the fn_default_and_validate in the main package

9. Fn_pre_check_mandatory
10. Fn_post_check_mandatory

    Any mandatory checks can be validated here.

11. Fn_pre_process
12. Fn_post_process

    These hook functions are specific to transaction call form screens. These are called from fn_process of the main package which in turn is called from fn_process of the calling function id

Refer maintenance and Transaction Screen development document for further explanation.