Javascript [Electronic resources] : The Definitive Guide (4th Edition) نسخه متنی

Availability

JavaScript
1.0; enhanced in JavaScript 1.1

Inherits from/Overrides

Inherits from HTMLElement

Synopsis

>document.links[] >
document.links.length

Properties

Link
inherits properties from HTMLElement and defines the following
properties. Many of the properties represent portions of a URL. For
each of these properties, the example given is a portion of the
following (fictitious) URL:

http://www.oreilly.com:1234/catalog/searchl?q=JavaScript&m=10#results

hash

A read/write string property that specifies the anchor portion of the
Link's URL, including the leading hash (#) mark. For example:
"#result". This anchor portion of a URL refers to a named
position within the document referenced by the Link. In HTML files,
positions are named with anchors created with the ><a
name=>anchor_name>">
tag.

host

A read/write string property that specifies the hostname and port
portions of a Link's URL. For example,
"www.oreilly.com:1234".

hostname

A read/write string property that specifies the hostname portion of a
Link's URL. For example "www.oreilly.com".

href

A read/write string property that specifies the complete text of the
Link's URL, unlike other Link URL properties that specify only
portions of the URL.

pathname

A read/write string property that specifies the pathname portion of a
Link's URL. For example "/catalog/searchl".

port

A read/write string (not a number) property that specifies the port
portion of a Link's URL. For example "1234".

protocol

A read/write string property that specifies the protocol portion of a
Link's URL, including the trailing colon. For example,
"http:".

search

A read/write string property that specifies the query portion of a
Link's URL, including the leading question mark. For example,
"?q=JavaScript&m=10".

target

A read/write string property that specifies the name of a Window
object (i.e., a frame or a top-level browser window) in which the
linked document should be displayed. See the
Link.target reference page for details.

text [Netscape 4]

Specifies the plain text, if any, between the
><a> and ></a> tags
of a link. Note that this property works correctly only if there are
no intervening HTML tags between the ><a> and
></a> tags. If there are other HTML tags, the
>text property may contain only a portion of the
link text. >HTMLElement.innerText provides the IE 4
equivalent of this Netscape-specific property.

Methods

Link inherits the methods of HTMLElement.

Event Handlers

Link inherits the event handlers of
HTMLElement and defines special behavior for the following:

onclick

Invoked when the user clicks on the link. In JavaScript 1.1, this
event handler may prevent the link from being followed by returning
>false. On Windows platforms in Netscape 3, this
event handler does not work for links created with the
><area> tag.

onmouseout

Invoked when the user moves the mouse off the link. Available in
JavaScript 1.1 and later.

onmouseover

Invoked when the user moves the mouse over the link. The
>status property of the current window may be set
here. May return >true to tell the browser not to
display the URL of the link.

HTML Syntax

A Link object is created with standard
><a> and ></a> tags.
The >href attribute is required for all Link
objects. If the >name attribute is also specified,
an Anchor object is also created:

<a href=>url"                  // The destination of the link
[ name=>anchor_tag" ]      // Creates an Anchor object
[ target=>window_name" ]   // Where the new document should be displayed
[ onclick=>handler" ]      // Invoked when link is clicked
[ onmouseover=>handler" ]  // Invoked when mouse is over link
[ onmouseout=>handler" ]   // Invoked when mouse leaves link
>
>link text or image             // The visible part of the link
</a>

In JavaScript 1.1 and later, a Link object is also created by each
><area> tag within a client-side image map.
This is also standard HTML:

<map name=>map_name">
<area shape=>area_shape"
coords=>coordinates"
href=>url"                 // The destination of the link
[ target=>window_name" ]   // Where the new document should be displayed
[ onclick=>handler" ]      // Invoked when area is clicked
[ onmouseover=>handler" ]  // Invoked when mouse is over area
[ onmouseout=>handler" ]   // Invoked when mouse leaves area
>
...
</map>

Description

The Link object represents a hypertext link or a clickable area of a
client-side image map in an HTML document. All links created with the
><a> and ><area> tags
are represented by Link objects and stored in the
>links[] array of the Document object. Note that
links created by both the ><a> and
><area> tags are stored in the same
array -- there is no distinction between them.

The destination of a hypertext link is a URL, of course, and many of
the properties of the Link object specify the contents of that URL.
The Link object is similar to the Location object, which also has a
full set of URL properties. In the case of the Location object, these
properties describe the URL of the currently displayed document.

In addition to its properties, the Link object has three event
handlers. The >onmouseover( ), >onclick(
), and >onmouseout( ) event handlers
specify code to be executed when the mouse passes over the hypertext
link, clicks on it, and moves off or out of the link's region
of the screen.

See Also

Anchor, Location; HTMLAnchorElement in the DOM reference section