This example creates context menu for an HTML table and illustrates how the content of a ContextMenu instance can be replaced on the fly based on the element that triggered its display.
Please Note: Opera users will need to do the following to use this example:
When adding context menus to large data structures like a
<table>
or large list (<ol>
or <ul>
), it is recommended to bind a single
YAHOO.widget.ContextMenu instance to the structure's root element, than to each of its
child nodes (<tr>
s or <li>
s).
Doing so significantly improves the performance of a web page or
application by reducing the number of "contextmenu" event handlers
as well as the number of YAHOO.widget.ContextMenu instances in memory.
Begin by creating an <table>
and giving
<tr>
elements that should have the same context menu a
similar class name.
Next, use the onContentReady
method of the Event utility to listen for when the <table>
element is are ready to be scripted.
Inside the function passed to the Event Utility's onContentReady
method, create a
shortcut to the Dom Utility (since it will be used frequently) and an object literal that maps each
class name to a set of MenuItem configuration properties.
Lastly, add a "triggerContextMenu" event handler to the ContextMenu instance.
This event handler makes use of the "contextEventTarget" property to determine
which <tr>
element was the target of the "contextmenu"
event. Once found, the <tr>
element's class name is
used to look up its corresponding menu items in the "oContextMenuItems"
map, which are then added to the ContextMenu instance via the "addItems" method.