A command
element can be used to invoke an operation that can come from multiple sources. For example, a clipboard paste operation can be invoked from the Edit menu, a context menu and by pressing a keyboard shortcut. You attach the code to the command using the oncommand
attribute. It will be called no matter how it is invoked by the user. In addition, disabling the command will automatically disable the menu items and keyboard shortcuts.
Commands are identified by their
. If you include the script id
chrome://global/content/globalOverlay.js
in your window, you can use the function goDoCommand
function to invoke the command. Using this function has the advantage that the command will be sent to the part of the UI which will respond to it. Typically, this will be the currently focused element.
Like a broadcaster
, commands forward attributes to other elements.
More information is available in the XUL tutorial. See also: command
attribute, commandset
element
Examples
The following code will send a paste command (cmd_paste
) to the currently focused element:
// First include chrome://global/content/globalOverlay.js goDoCommand("cmd_paste");
Example with two buttons
<commandset><command id="cmd_openhelp" oncommand="alert('Help');"/></commandset> <button label="Help" command="cmd_openhelp"/> <button label="More Help" command="cmd_openhelp"/>
Attributes
-
disabled
- Type: boolean
-
Indicates whether the element is disabled or not. If this element is set to
true
the element is disabled. Disabled elements are usually drawn with grayed-out text. If the element is disabled, it does not respond to user actions, it cannot be focused, and thecommand
event will not fire. -
Visible controls have a
disabled
property which, except for menus and menuitems, is normally preferred to use of the attribute, as it may need to update additional state.
-
label
- Type: string
-
The label that will appear on the element. If this is left out, no text appears. For an editable
menuitem
element the value of this attribute is copied to themenulist
.value property upon user selection of themenuitem
.
oncommand
- Type: script code
- This event handler is called when the command is activated. This occurs when a user selects a menu item or presses a keyboard shortcut attached to the command.
Properties
Inherited Properties |