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Behavior Events

Pro Behavior

A behavior is triggered by a source event. The event determines what context values are available to expressions and actions.

EventTypical use
OnTagAddedValidate or react when a tag is added.
OnTagRemovedClean up or report after a tag is removed.
OnTagReplacedValidate migrations and redirect resolution.
OnActorAddedToLevelCheck newly placed Actors.
OnActorRenamedValidate naming conventions or tag-dependent rules.
OnActorClassChangedValidate class and tag combinations.
OnComponentAddedToActorAuto-tag or validate added components.
OnComponentRemovedFromActorReport follow-up problems.
OnComponentRenamedValidate component naming conventions.
OnAssetOpenedCheck Asset Tags or metadata when an asset is opened.
OnAssetSavedValidate asset tags before save.
OnManualTriggerRun a behavior manually from editor tooling.

Depending on the event, these values can be available:

  • Actor
  • Component
  • Source Object
  • Tag Name
  • Previous Tag Name
  • Asset Object
  • flags such as auto tag or assign operation

The helper functions in UJ2TagBehaviorBlueprintLibrary expose common event context reads such as GetEventActor, GetEventComponent, GetEventTagName, and GetEventSourceObject.

OnManualTrigger is useful for checks that should not run on every editor change. Manual behaviors can be launched from the Behavior Editor or from supported tag context actions.

Choose the narrowest event that matches the rule. A behavior that only needs to react to tag assignment should not run from broader Actor lifecycle events.