Which event handler always needs to return a boolean value?

The before commit event handler is designed to allow you to implement validation or business logic right before the changes to the data are committed to the database. This handler needs to return a boolean value because it determines whether the commit process should proceed or be aborted based on the conditions you define in your logic.

If the handler returns true, it indicates that the commit can proceed. Conversely, if it returns false, it prevents the transaction from being completed, allowing for the management of data integrity and implementing necessary validations. This is crucial in scenarios where specific conditions must be met to ensure the data being saved is valid or acceptable.

In contrast, the other event handlers like after commit, on change, or before delete do not require a boolean return value because their purposes are different. For example, after commit functions are executed after the data has been saved, and validating or preventing actions isn't applicable. Similarly, the on change handler reacts to changes in a user interface element and does not influence commit logic. The before delete handler can include logic but does not strictly require a boolean return value to influence deletion in the same manner.