Understanding PeopleCode Programs and Events
Every PeopleCode program is associated with an aspect of a Application Designer definition and an event. Events are predefined points either in the Component Processor flow or in the program flow. As each event is encountered, it fires on each component, triggering any PeopleCode program associated with that component and that event. Each definition in Application Designer can have an event set, that is, a group of events appropriate to that definition. A definition can have zero or one PeopleCode programs for each event in its event set.
Some definitions have events that fall outside the Component Processor flow. These definitions include Application Engine programs, component interfaces, and application packages. In addition, security has a signon event,. which is described in the documentation for the definition or topic.