HTMLElement.onkeypress |
the handler invoked when the user presses a
key |
Availability
JavaScript 1.2; HTML 4.0
Synopsis
<element onkeypress="handler" ... >
element.onkeypress
Description
The onkeypress property of an HTMLElement object
specifies an event handler function that is invoked when the user
presses a key over the element. A keypress
event is generated after a key down event and before the
corresponding key up event. The keypress and key down events are
similar. Unless you care about receiving individual key up events,
you should use onkeypress instead of
onkeydown.
The initial value of this property is a function that contains the
JavaScript statements specified by the onkeypress
attribute of the HTML tag that defined the object. When an event
handler function is defined by an HTML attribute, it is executed in
the scope of element rather than in the
scope of the containing window.
In the Netscape 4 event model, the onkeypress
handler function is passed an Event object as an argument. In the IE
event model, no argument is passed, but the applicable Event object
is available as the event property of the Window
object that contains the element.
The character code of the key pressed is contained in the
which property of the Event object in Netscape and
in the keyCode property of the Event object in IE.
You can convert this keycode to a string with
String.fromCharCode( ). The modifier keys in
effect can be determined from the Event.modifiers
property in Netscape or with Event.shiftKey( ) and
related methods in IE.
In Netscape, you can cancel processing of the keystroke by returning
false from this handler. In IE, you cancel
processing by setting Event.returnValue to
false. In IE, this handler may return an alternate
keycode that is used in place of the key actually pressed by the
user.
See Also
Event; Chapter 19
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