Type Alias EventOptions

When set to true this registration is guarded. Further attempts to register an event by the same name will not be possible as long as a guarded event exists with the same name.

Provides a hint on the trigger type. It may be a string 'sync' or 'async'. Any other value is not recognized and internally type will be set to undefined. If the callback is a function defined with the async modifier it will automatically be detected as async.