Register Event Class

Class: CJL_RegisterEvent

Summary:

JavaScript Class that allows for generic setting and removing of event listeners.

Submitted: 01/28/2003

Created by: CodeHouse.com

Browser Compatibility for all Methods in this Module:

Internet Explorer for Windows 5.0+
Netscape 6.1+
Mozilla 1.0+
Opera 7.0+
Safari 1.0+

Demo

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Source Code

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/******************************************************** * Copyright (C) 2002-2003, CodeHouse.com. All rights reserved. * CodeHouse(TM) is a registered trademark. * * THIS SOURCE CODE MAY BE USED FREELY PROVIDED THAT * IT IS NOT MODIFIED OR DISTRIBUTED, AND IT IS USED * ON A PUBLICLY ACCESSIBLE INTERNET WEB SITE. * * CodeHouse.com JavaScript Library Module: Register Event Class * * You can obtain this script at http://www.codehouse.com ********************************************************/ function CJL_RegisterEvent(elem, type, listener, useCapture, noAutoStart) { var proto = arguments.callee.prototype; this.e = elem; this.type = type; this.cap = useCapture; this.l = listener; proto.start = function() { if( this.e.attachEvent ) { this.e.attachEvent("on" + this.type, this.l); } else if( this.e.addEventListener ) { this.e.addEventListener(this.type, this.l, this.cap); } } if( ! noAutoStart ) { this.start(elem, type, listener); } proto.stop = function() { if( this.e.detachEvent ) { this.e.detachEvent("on" + this.type, this.l); } else if( this.e.removeEventListener ) { this.e.removeEventListener(this.type, this.l, this.cap); } } }

Class Index

CJL_RegisterEvent

start()
stop()

Constructor: CJL_RegisterEvent

CJL_RegisterEvent(elem, type, listener, noAutoStart, useCapture)

Description:

Creates a new CJL_RegisterEvent class for attaching a listener method to an element, for a specific event type. Also allows for the programmatic starting and stopping of event listening.

Example Usage:

Attaches a mousedown listener, named myListener to the document element:

new CJL_RegisterEvent(document, "mousedown", myListener);

Parameters

elem:

Element to attach the event listener method to

type:

Event type to set the event listener method to listen to

listener:

Event listening method that gets called to process events for elem

noAutoStart:

If this parameter is true, listener is not automatically attached to elem. If this parameter is false, listener is automatically attached to elem.

In the example below, since the noAutoStart parameter was not supplied to the constructor, noAutoStart is implicitly false. Because noAutoStart is false, the constructor automatically attaches the listener — myListener to the element — document.

new CJL_RegisterEvent(document, "mousedown", myListener);

The example below does exactly the same thing as the example above. However, it does not attach myListener to document in the constructor. It tells the constructor not to automatically attach a listener by supplying a true value for the noAutoStart paramater. myListener is attached to document by calling the start() method.

reg = new CJL_RegisterEvent(document, "mousedown", myListener, false, true);
reg.start();

useCapture:

This parameter allows event capturing only for browsers which support DOM Level 2 Event Capture. This parameter is ignored for browsers which don't support the standard.

Methods

start()

Starts listening for events for the target element — elem specified in the constructor.

stop()

Stops listening for events for the target element — elem specified in the constructor.

Support

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