YUI Library Examples: Menu Family: Listening For Menu Events

Adding DOM-based event handlers to Menu and MenuItem instances.

All of the events for Menu and MenuItem (including DOM-based events such as "mouseover" or "click") are implemented as instances of Custom Event (YAHOO.util.CustomEvent). Please note: To listen for DOM-based events always use the provided Custom Event-based interface rather than attaching handlers directly to a Menu's DOM elements.

Add event listeners through the subscribe method. The following example demonstrates how to subscribe to the "show" and "hide" events:

/*
     Generic event handler used to log info about the DOM events for 
     the Menu instance.
*/

function onMenuEvent(p_sType, p_aArgs) {

var oDOMEvent = p_aArgs[0];

YAHOO.log(("Id: " + this.id + ", " +
               "Custom Event Type: " + p_sType + ", " +                  
               "DOM Event Type: " + oDOMEvent.type), 
               "info", "example10");
}

/*
     Generic event handler used to log info about the DOM events for 
     each MenuItem instance.
*/

function onMenuItemEvent(p_sType, p_aArgs) {

var oDOMEvent = p_aArgs[0];

YAHOO.log(("Index: " + this.index + ", " +
               "Group Index: " + this.groupIndex + ", " +
               "Custom Event Type: " + p_sType + ", " +                  
               "DOM Event Type: " + oDOMEvent.type
               ), "info", "example10");
    
}

/*
	Instantiate a Menu:  The first argument passed to the constructor
	is the id for the Menu element to be created, the second is an 
	object literal of configuration properties.
*/

var oMenu = new YAHOO.widget.Menu("basicmenu", { fixedcenter: true });

// Subscribe to the Menu instance's "itemAdded" event

oMenu.subscribe("itemAdded", function (p_sType, p_aArgs) {

var oMenuItem = p_aArgs[0];
    
    /*
         Subscribe to each MenuItem instance's DOM events as they
         are added to the Menu instance.
    */

oMenuItem.subscribe("mouseover", onMenuItemEvent);
    oMenuItem.subscribe("mouseout", onMenuItemEvent);
    oMenuItem.subscribe("mousedown", onMenuItemEvent);
    oMenuItem.subscribe("mouseup", onMenuItemEvent);
    oMenuItem.subscribe("click", onMenuItemEvent);
    oMenuItem.subscribe("keydown", onMenuItemEvent);
    oMenuItem.subscribe("keyup", onMenuItemEvent);
    oMenuItem.subscribe("keypress", onMenuItemEvent);

});

//  Subscribe to every DOM event for the Menu instance.

oMenu.subscribe("mouseover", onMenuEvent);
oMenu.subscribe("mouseout", onMenuEvent);
oMenu.subscribe("mousedown", onMenuEvent);
oMenu.subscribe("mouseup", onMenuEvent);
oMenu.subscribe("click", onMenuEvent);
oMenu.subscribe("keydown", onMenuEvent);
oMenu.subscribe("keyup", onMenuEvent);
oMenu.subscribe("keypress", onMenuEvent);

/*
    Add items to the Menu instance by passing an array of object literals 
    (each of which represents a set of YAHOO.widget.MenuItem 
    configuration properties) to the "addItems" method.
*/

oMenu.addItems([

"MenuItem 0",

"MenuItem 1",

/*
             Add a disabled menu item to demonstrate that disabled 
             items do not respond to DOM events.
        */
        { text: "MenuItem 2", disabled: true },

"MenuItem 3",

"MenuItem 4"

]);

/*
    Since this Menu instance is built completely from script, call the 
    "render" method passing in the DOM element that it should be 
    appended to.
*/

oMenu.render("rendertarget");

Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.

YUI Library Examples: Menu Family: Listening For Menu Events

Adding DOM-based event handlers to Menu and MenuItem instances.

Configuration for This Example

YUI Logger Output:

Menu Family Examples:

More Menu Family Resources: