Callbacks

External Callbacks enable you to add Listeners to an ObjectContainer for the following db4o events

QueryStarted and QueryFinished events accept QueryEventArgs as a parameter and can be used to gather query statistics information.

Created, Activated, Deactivated, Updated and Deleted events accept ObjectEventArgs and can be used to gather statistics information or to initiate some special behavior after the action has been taken.

Creating, Activating, Deactivating, Updating and Deleting events accept CancellableObjectEventArgs. Their primary usage is to perform action validity check and to stop the execution if necessary.

Committing event can be used to check some application-specific conditions before commit. For example it can

be used to check unique constraints. Committing event accepts CommitEventArgs as a parameter.

Committed event is raised when the container has completely finished the commit operation. Event subscribers get the notification in a separate thread. Committed event accepts CommitEventArgs.