Exit points

An exit point is a callback function that you write. It is executed at a predefined strategic point by the server.

Four types of exit points are supported: pre-data access, post-data access, validation, and on-fail.

Pre-data access
The pre-data access function is called before the DAL function (but after validate functions).
Post-data access
The post-data access function is called after the DAL function.
Validation
The validation function is called before standard insert and standard update operations, and also before the pre-data access functions. It provides a common place to put validation code.
On-fail
The on-fail function is called if an error occurs in the data access function.
Exit point parameters
In most cases, the parameters to an exit point method must include the parameters to the method to which the exit point belongs and the return type of the method to which the exit point belongs.
Exit point uses
Use exit points for validation or for completing a business process.
Exit point misuses
Do not use exit points to populate incomplete fields in incoming parameters.