Features added after version 1

he following lists summarize the additions and changes to JavaScript since Navigator 2.0. The lists show new functionality and changed functionality.

Note

Language features added in Navigator 3.0 are not incorporated in LiveWire 1.0.

New functionality

The following table lists objects, properties, methods, event handlers, and other features added in JavaScript for Navigator 3.0.

Category	Feature	Description
New objects	Applet	Includes a Java applet in a web page
	Area	Defines image maps
	Array	Lets you create arrays and work with them
	Boolean	Lets you work with Boolean values
	FileUpload	A file upload element on an HTML form; a file upload element lets the user supply a file as input
	Function	Specifies a string of JavaScript code to be compiled as a function
	Image	An image on an HTML form
	MimeType	A MIME type (Multipart Internet Mail Extension) supported by the client
	Number	Lets you work with numeric values
	Option	A Select object option created using the Option() constructor
	Plugin	A plug-in module installed on the client
	Object deletion	You can remove an object by setting its object reference to null. See "Object deletion".
New properties	border	A string specifying the width, in pixels, of an image border
	closed	Specifies whether a window is closed
	complete	A boolean value that indicates whether Navigator has completed its attempt to load an image
	constructor	Specifies the function that creates an object prototype
	current	A string specifying the complete URL of the current history entry
	description	A description of a MIME type or plug-in
	domain	Specifies the domain name of the server that served a document
	enabledPlugin	The Plugin object for the plug-in that is configured for the specified MIME type
	filename	The name of a plug-in file on disk
	height	A string specifying the height of an image in pixels
	hspace	A string specifying a margin in pixels between the left and right edges of an image and the surrounding text
	lowsrc	A string specifying the URL of a low-resolution version of an image to be displayed in a document
	MAX_VALUE	The maximum numeric value representable in JavaScript
	MIN_VALUE	The smallest positive numeric value representable in JavaScript
	NaN	A special value representing Not-A-Number. This value is represented as NaN
	NEGATIVE_INFINITY	A special numeric value representing negative infinity; this value is represented as "-Infinity"
	next	A string specifying the complete URL of the next history entry
	opener	Specifies the window of the calling document when a window is opened using the open method
	POSITIVE_INFINITY	A special numeric value representing infinity. This value is represented as "Infinity"
	previous	A string specifying the complete URL of the previous history entry
	prototype	Defines a property that is shared by all objects of the specified type
	src	A string specifying the URL of an image to be displayed in a document
	suffixes	A string listing possible file suffixes (also known as file name extensions) for the MIME type
	type	Specifies the type of form element or the name of a MIME type
	vspace	A string specifying a margin in pixels between the top and bottom edges of an image and the surrounding text
	width	A string specifying the width of an image in pixels
New arrays	applets	Reflects all the <APPLET> tags in a document in source order
	embeds array	Reflects all the <EMBED> tags in a document in source order
	history array	Reflects all the history entries in a window in source order
	images	Reflects all the <IMG> tags in a document in source order (images created with the Image() constructor are not included in the images array)
	mimeTypes	Reflects all the MIME types supported by the client (either internally, via helper applications, or by plug-ins)
	plugins	Reflects all the plug-ins installed on the client in source order
New methods	javaEnabled	Specifies whether Java is enabled
	join	Joins all elements of an array into a string
	refresh	Makes newly installed plug-ins available, updates related arrays such as the plugins array, and optionally reloads open documents that contain plug-ins
	reload	Forces a reload of the window's current document
	replace	Loads the specified URL over the current history entry
	reset method	Simulates a mouse click on a reset button
	reverse	Transposes the elements of an array: the first array element becomes the last and the last becomes the first
	scroll	Scrolls a window to a specified coordinate
	sort	Sorts the elements of an array
	split	Splits a String object into an array of strings by separating the string into substrings
	taintEnabled	Specifies whether data tainting is enabled
	valueOf	Returns the primitive value of an object
New functions	taint	Adds tainting to a data element or script
	untaint	Removes tainting from a data element or script
New event handlers	onAbort	Executes JavaScript code the user aborts the loading of an image
	onError	Executes JavaScript code when the loading of a document or image causes an error
	onMouseOut	Executes JavaScript code when the mouse pointer leaves an area (client-side image map) or link
	onReset	Executes JavaScript code when a reset event occurs
	Resetting event handlers from within JavaScript	In JavaScript for Navigator 3.0, you can reset an event handler specified by HTML from within JavaScript. See "Calling event handlers explicitly".
New operators	typeof	Returns the data type of its operand
	void	Specifies an expression to be evaluated without returning a value
New HTML tags and attributes	JavaScript entities	JavaScript entities for HTML attribute values. See "Using JavaScript expressions as HTML attribute values".
	SRC attribute of <SCRIPT> the tag	Allows you to use JavaScript code in an external file. See "Specifying a file of JavaScript code".
	LANGUAGE attribute of <SCRIPT> the tag	Allows you to specify the JavaScript version. See "Specifying the JavaScript version".
	<NOSCRIPT> tag	Displays alternate content for old browsers or when the user has disabled JavaScript in Navigator. See "Specifying alternate content with the NOSCRIPT tag".
Java-JavaScript communication	LiveConnect	LiveConnect enables communication between JavaScript and Java applets in a page and between JavaScript and plug-ins loaded on a page. See Chapter 4, "LiveConnect."
Plug-in detection	Determining installed plug-ins	You can use JavaScript to determine whether a user has installed a particular plug-in. You can also determine whether a client is capable of handling a particular MIME (Multipart Internet Mail Extension) type. See "Determining installed plug-ins".
Security	Data tainting	Navigator prevents scripts from fetching private information such as directory structures or user session history. Data tainting retains the security restriction but provides a means of secure access to specific components on a page. See "Using data tainting for security".

Changed functionality

The following table lists changes to functionality that existed in JavaScript for Navigator 2.0.

Category	Feature	Description
Objects	Form object	Added reset method; added onReset event handler
	Frame	Added blur, focus, and scroll methods; added onBlur, onError, and onFocus event handlers
	history object	Added current, next, and previous properties
	Link object	Added onMouseOut event handler
	location	Added reload and replace methods; changed the way documents are loaded when location is set
	navigator	Added mimeTypes and plugins arrays; added javaEnabled method
	Object prototypes (see prototype)	Added ability to create properties to be shared by all objects of the same type
	Select object	Programmatically modifiable Select objects and the ability to add options and delete options
	String	Added String() constructor (in previous releases, you construct strings by quoting characters); added prototype property; added split method; added ability to pass strings among scripts in different windows or frames (in previous releases, you had to add an empty string to another window's string to reference it)
	window object	Added closed and opener properties; added blur, focus, and scroll methods; added onBlur, onError, and onFocus event handlers
	Indexing object properties	If you initially define a property by its name, you must always refer to it by its name, and if you initially define a property by an index, you must always refer to it by its index. See "Indexing object properties".
Properties	Indexing arrays with strings	Added ability to index arrays using strings (as in an associative array). See "Navigator's object arrays", "Array object", and "Array".
Methods	blur	Now works for window, frame, Button, Checkbox, FileUpload, Radio, Reset, and Submit objects
	close (window object)	Has new security enhancements
	eval	Now a method of every object (was previously a built-in function); it evaluates a string of JavaScript code in the context of the specified object
	focus	Now works for window, frame, Button, Checkbox, FileUpload, Radio, Reset, and Submit objects
	open (document object)	Added "replace" parameter, which causes the new document to reuse the history entry that the previous document used; document.open() or document.open("text/html") now clears the current document if it has finished loading
	random	Now works on all platforms
	toString	Added radix parameter, which specifies the base to use for representing numeric values
	write	Users can print and save generated HTML using the commands on the File menu
	writeln	Users can print and save generated HTML using the commands on the File menu
Functions	isNaN	Now works on all platforms (in previous releases, worked only on Unix platforms)
	parseFloat	Now returns NaN on all platforms if the first character of the specified string cannot be converted to a number; in previous releases, it returned NaN on Solaris and Irix and zero on all other platforms
	parseInt	Now returns NaN on all platforms if the first character of the specified string cannot be converted to a number; in previous releases, it returned NaN on Solaris and Irix and zero on all other platforms
Event handlers	onBlur	Now applies to window, frame, Button, Checkbox, FileUpload, Radio, Reset, and Submit objects
	onClick	Added the ability to return false to cancel the action associated with a click event
	onFocus	Now applies to window, frame, Button, Checkbox, FileUpload, Radio, Reset, and Submit objects