eventHandlerComponent

<!--c:eventHandler-->
<aura:component>
    <aura:attribute name="messageFromEvent" type="String"/>
    <aura:attribute name="numEvents" type="Integer" default="0"/>

    <!-- Note that name="cmpEvent" in aura:registerEvent
     in ceNotifier.cmp -->
    <aura:handler name="cmpEvent" event="c:testEvent" action="{!c.handleComponentEvent}"/>

    <!-- handler contains the notifier component -->
    <c:eventNotifier />
    
    <p>{!v.messageFromEvent}</p>
    <p>Number of events: {!v.numEvents}</p>

</aura:component>