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:


1	/*
2	Generic event handler used to log info about the DOM events for
3	the Menu instance.
4	*/
5
6	function onMenuEvent(p_sType, p_aArgs) {
7
8	var oDOMEvent = p_aArgs[0];
9
10	YAHOO.log(("Id: " + this.id + ", " +
11	"Custom Event Type: " + p_sType + ", " +
12	"DOM Event Type: " + oDOMEvent.type),
13	"info", "example10");
14	}
15
16
17	/*
18	Generic event handler used to log info about the DOM events for
19	each MenuItem instance.
20	*/
21
22	function onMenuItemEvent(p_sType, p_aArgs) {
23
24	var oDOMEvent = p_aArgs[0];
25
26	YAHOO.log(("Index: " + this.index + ", " +
27	"Group Index: " + this.groupIndex + ", " +
28	"Custom Event Type: " + p_sType + ", " +
29	"DOM Event Type: " + oDOMEvent.type
30	), "info", "example10");
31
32	}
33
34
35	/*
36	Instantiate a Menu: The first argument passed to the constructor
37	is the id for the Menu element to be created, the second is an
38	object literal of configuration properties.
39	*/
40
41	var oMenu = new YAHOO.widget.Menu("basicmenu", { fixedcenter: true });
42
43
44	// Subscribe to the Menu instance's "itemAdded" event
45
46	oMenu.subscribe("itemAdded", function (p_sType, p_aArgs) {
47
48	var oMenuItem = p_aArgs[0];
49
50	/*
51	Subscribe to each MenuItem instance's DOM events as they
52	are added to the Menu instance.
53	*/
54
55	oMenuItem.subscribe("mouseover", onMenuItemEvent);
56	oMenuItem.subscribe("mouseout", onMenuItemEvent);
57	oMenuItem.subscribe("mousedown", onMenuItemEvent);
58	oMenuItem.subscribe("mouseup", onMenuItemEvent);
59	oMenuItem.subscribe("click", onMenuItemEvent);
60	oMenuItem.subscribe("keydown", onMenuItemEvent);
61	oMenuItem.subscribe("keyup", onMenuItemEvent);
62	oMenuItem.subscribe("keypress", onMenuItemEvent);
63
64	});
65
66
67	// Subscribe to every DOM event for the Menu instance.
68
69	oMenu.subscribe("mouseover", onMenuEvent);
70	oMenu.subscribe("mouseout", onMenuEvent);
71	oMenu.subscribe("mousedown", onMenuEvent);
72	oMenu.subscribe("mouseup", onMenuEvent);
73	oMenu.subscribe("click", onMenuEvent);
74	oMenu.subscribe("keydown", onMenuEvent);
75	oMenu.subscribe("keyup", onMenuEvent);
76	oMenu.subscribe("keypress", onMenuEvent);
77
78
79	/*
80	Add items to the Menu instance by passing an array of object literals
81	(each of which represents a set of YAHOO.widget.MenuItem
82	configuration properties) to the "addItems" method.
83	*/
84
85	oMenu.addItems([
86
87	"MenuItem 0",
88
89	"MenuItem 1",
90
91	/*
92	Add a disabled menu item to demonstrate that disabled
93	items do not respond to DOM events.
94	*/
95	{ text: "MenuItem 2", disabled: true },
96
97	"MenuItem 3",
98
99	"MenuItem 4"
100
101	]);
102
103
104	/*
105	Since this Menu instance is built completely from script, call the
106	"render" method passing in the DOM element that it should be
107	appended to.
108	*/
109
110	oMenu.render("rendertarget");
	view plain \| print \| ?

/*
     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 Logger Output:

Logger Console

INFO 762ms (+0) 12:37:34 AM:

MenuManager

MenuItem yui-gen4 successfully registered.

INFO 762ms (+1) 12:37:34 AM:

Menu basicmenu

Item added. Text: MenuItem 4, Index: 4, Group Index: 0

INFO 761ms (+0) 12:37:34 AM:

MenuManager

MenuItem yui-gen3 successfully registered.

INFO 761ms (+0) 12:37:34 AM:

Menu basicmenu

Item added. Text: MenuItem 3, Index: 3, Group Index: 0

INFO 761ms (+0) 12:37:34 AM:

MenuManager

MenuItem yui-gen2 successfully registered.

INFO 761ms (+0) 12:37:34 AM:

Menu basicmenu

Item added. Text: MenuItem 2, Index: 2, Group Index: 0

INFO 761ms (+0) 12:37:34 AM:

MenuManager

MenuItem yui-gen1 successfully registered.

INFO 761ms (+0) 12:37:34 AM:

Menu basicmenu

Item added. Text: MenuItem 1, Index: 1, Group Index: 0

INFO 761ms (+1) 12:37:34 AM:

MenuManager

MenuItem yui-gen0 successfully registered.

INFO 760ms (+1) 12:37:34 AM:

Menu basicmenu

Item added. Text: MenuItem 0, Index: 0, Group Index: 0

INFO 759ms (+0) 12:37:34 AM:
MenuManager
Menu basicmenu successfully registered.

INFO 759ms (+0) 12:37:34 AM:
MenuManager
DOM event handlers initialized.

INFO 759ms (+3) 12:37:34 AM:

Menu basicmenu

No source element found. Created element with id: basicmenu

INFO 756ms (+756) 12:37:34 AM:
LogReader  instance0
LogReader initialized

INFO 0ms (+0) 12:37:33 AM:
global
Logger initialized

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:

Logger Console

Menu Family Examples:

More Menu Family Resources: