home / documentation / reference / hm_onitemover

HM_OnItemOver

Description:

The custom (user defined) method that is called when the user rolls their mouse over a menu item.

Value:

JavaScript function.

Applies To:

Menu Items.

Browser Compatibility:

HM_OnItemOver is supported in all browsers.

Parameters:

(itemEl)

itemEl is the HTML element for the menu item

Comments:

HM_OnItemOver is a HierMenus Menu Event Hook; a means for you to execute your own custom JavaScript code from within normal HierMenus processing. All menu event hooks expect to be set to the name of a custom function (typically of your own creation, although the HM_Loader.js file contains some custom functions designed for use with event hooks), a function literal, or a dynamically generated function.

The function you create for use with this menu event hook should be designed as a method of the item object, i.e., the internal item object that HierMenus creates to track the various unique parameters of the item itself. Thus, the this keyword, within the context of your custom function, refers directly to the item object.

The item object (referred to by this) is not the same as the item element. The item object is the internal structure that HierMenus uses to track various pieces of information specific to this item. The item element is the actual HTML page element that represents the item itself. You access the item object via the this keyword within your custom method; you access the item element via the first parameter passed to the function.

When using HM_OnItemOver note that it is not guaranteed that the action that is being called for is strictly necessary on the item. Most browsers will refire the mouseover event on an element repeatedly as the mouse rolls over elements that are themselves contained within the target element. HierMenus attempts to avoid this behavior (i.e., HierMenus attempts to call the mouseoover handler for the item only once, when the mouse actually enters the item element) but this cannot be relied upon for all browsers. Your methods will need to be designed with this fact in mind.

For further usage and implementation information, see the mini-tutorial Menu Event Hooks.

Example Method:

// write a message to the status 
// bar when the user rolls over an item
function HM_fc_ItemOver() {
   window.status="Welcome to menu item "+
                 this.MenuID+" "+this.ItemCount+"!";
}

Example Settings:

// Ok:
HM_OnItemOver:HM_fc_ItemOver,
HM_OnItemOver:null,  // remove hook for this item

// Incorrect:
HM_OnItemOver:"HM_fc_ItemOver",
   // do not quote function names here
HM_OnItemOver:"null", 
   // do not quote null here

Default:

null

See Also:

HM_OnMove, HM_OnVisibilityToggle, HM_OnCreateMenu, HM_OnMenuCreated, HM_OnItemHilite, HM_OnBuildMenus, HM_OnItemClick, HM_OnItemHover, HM_OnCreateItem, HM_OnItemCreated, HM_OnMenuOver, HM_OnMenuOut, HM_OnItemOut, HM_OnLink, setTrans, killTrans, Menu Event Hooks Mini-Tutorial