grails install-plugin falcone-util

class InvoiceService {
    def writeOffInvoice(def invoice) {
      invoice.hasBeenWrittenOff = true
      notifyAccounting()
      publishEvent("invoiceWriteOff", invoice)
    }
  }

class SomeSpringBean {
  EventBroker eventBroker
  def someSpringMethod() {
    //Do something
    eventBroker.publish("someSpringMethodCalled", this) 
  }
}

def doWithEvents = {ctx ->
       tenantChanged() { //The name of the event to subscribe to
           event-> //The event object
           println "Tenant changed from ${event.old} to ${event.new}" //Your event handling code
       }
      
       //The "invalidateCredentials" parameter used below is an optional 
       //parameter to uniquely identify your event consumer for debugging 
       //purposes.  If your consumer throws an exception, for example, 
       //the event processing system can print out that string to help you 
       //track down the problem better.
       tenantChanged("invalidateCredentials") {event->
           SecurityUtils.logOutCurrentUser()
       }
       hibernate.criteriaCreated("onlyReturnActiveRecords") {
           criteriaContext -> criteriaContext.criteria.add(Expression.eq("status", "active"))
       }  
  }

grails-app/conf/events.groovy:

consumers = {
    
    tenantChanged() {
        event->
        //Code goes here
    }

    hibernate.criteriaCreated {
        criteria->
    }
}

class SomeBean {
    EventBroker eventBroker
    void init() {
        eventBroker.subscribe("someEvent") {
            event ->
            //When the event is thrown, reload this instance.
            this.reload();
        }
    }

}