[CAUSEWAY-786] Allow event bus subscribers to veto interactions by throwing a RecoverableException or NonRecoverableException

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: core-1.4.0
• Fix Version/s: core-1.5.0
• Component/s: Core, Viewer Wicket
• Assignee: Daniel Keir Haywood
• Reporter: Daniel Keir Haywood
• Created: 21/May/14 07:01
• Updated: 09/Jun/14 23:25
• Resolved: 22/May/14 06:41

Description

If the subscriber method throws either an org.apache.isis.applib.RecoverableException or an org.apache.isis.applib.NonRecoverableException, then the transaction will be aborted and the interaction effectively vetoed.

A RecoverableException will be rendered in a user-friendly manner to the end-ser, a NonRecoverableException rendered as a serious/unexpected error.

Any other exception type (eg an "accidental" one such as NullPointerException) will be ignored. This preserves previous behaviour.