ui:menuTriggerPress

Indicates that a menu trigger is clicked.

For example, the ui:menuTrigger component registers this event so it can be fired by the component.

1<aura:registerEvent name="menuTriggerPress"  type="ui:menuTriggerPress"
2                    description="The event fired when the trigger is clicked." />

You can handle this event in a component that extends ui:menuTrigger, such as in a ui:menuTriggerLink component instance.

1<ui:menu>
2    <ui:menuTriggerLink aura:id="trigger" label="Contacts" menuTriggerPress="{!c.triggered}"/>
3        <ui:menuList class="actionMenu" aura:id="actionMenu">
4            <ui:actionMenuItem aura:id="item1" label="All Contacts" click="{!c.doSomething}"/>
5            <ui:actionMenuItem aura:id="item2" label="All Primary" click="{!c.doSomething}"/>
6        </ui:menuList>
7</ui:menu>

This client-side controller retrieves the label of the trigger when it’s clicked.

1({
2    triggered : function(component, event, helper) {
3        var trigger = component.find("trigger");
4        
5        // Get the label on the trigger
6        var triggerLabel = trigger.get("v.label");
7    }
8})

Lightning Components Developer Guide

ui:menuTriggerPress