Sugar Developer Guide Version 5.1

Business Logic Hooks

Custom Logic (or "Business Logic Hooks") allows you to add functionality to certain actions, such as before a bean save, in an upgrade-safe manner. This is accomplished by defining hooks, which are placed in the custom/ directory, which will be called in the SugarBean in response to events at runtime. Because the code is located separate from the core SugarCRM code, it is upgrade-safe.

See this SugarForge project for a complete example of a useful business hook.