external.MenuSelectHandler - string - Read/Write. Specifies the
script function to be called to handle the notification. Only the
function name must be specified (no brackets or parameters). For
example:
external.MenuSelectHandler = "MySelectMenuHandler";
In the page function should be defined as:
function MySelectMenuHandler(sender) {
// Implementation ...
}
sender parameter is the MenuItem
object currently selected by the user.
The property can be inspected by the script in order to
determine the currently registered handler.
external.MenuSelectHandlerNamespace - string - Read/Write.
Specifies the namespace that holds the function specified in the MenuSelectHandler property. the string syntax is "namespacetype=namespacename".
Currently only frame is supported as namespace type. In case of
no frames property should be empty (i.e. care about it only if you
have frames). Example:
external.MenuSelectHandlerNamespace = "frame=main";
If you have a FRAMESET with a frame called "main" or
IFRAME with that name.
Most of the desktop applications track the pop-up menus and for
example display some hint text about the menu items selected by the
user in the status bar. With ALPFrame DTHML pages are able to do
something similar or more complex in response to the menu tracking.
Handler function receives as parameter the menu item that is
currently selected (not yet clicked) and is able to use for example
its info property or more complex logic to determine what to do. For
example this function is able to change the DHTML page, some text in
it or/and a hint images and so on.
The only suggestion to the developers is to take care about the
time needed to perform the task. Menu selection changes as the user
moves the mouse through the menu thus for example downloading an
image from the network for the selection will be too slow, but
changing a text and/or style of some elemnt(s) of the page will be
fast enough. It is recommended to make a test on a slower machine if
you are going to implement a complex processing and optimize that
part of your page for higher performance.
For example usage see the elements example in the ALPFrame
samples.
Note that the similar properties - InitMenuHandler
and InitMenuHandlerNamespace have different purpose. They are used
to specify a routine to inspect the menu items state before entering
the window menu and MenuSelectHandler is used to specify handler for
the menu tracking - changing the state of the menu items in the code
that handles the menu selection is not appropriate.
