| Document |
represents an HTML document |
Availability
JavaScript 1.0; enhanced in JavaScript
1.1, Netscape 4, and IE 4
Inherits from/Overrides
Inherits from HTMLElement
Synopsis
window.document
document
Properties
Document
inherits properties from HTMLElement and defines the following
properties. Netscape and Internet Explorer both define a number of
incompatible Document properties that are used mostly for DHTML; they
are listed separately after these properties.
- alinkColor
-
alinkColor is
a string property that specifies the color of activated links in
document. Browsers may display this color
between the times that the user presses and releases the mouse button
over the link. The alink attribute of the
<body> HTML tag specifies the initial value
of this property. This property may be set, but only in the
<head> of the document. See also the color
properties of HTMLBodyElement in the DOM reference section.
- anchors[]
-
An array of Anchor objects, one for
each anchor that appears in document. An
anchor is a named position within the document that can serve as the
target of a hypertext link. The anchors[] array
has anchors.length elements, numbered from zero to
anchors.length-1. Do not confuse anchors with
hypertext links, which are represented in JavaScript by the Link
objects in the Document.links[] array.
Prior to JavaScript 1.2, the Anchor object was unimplemented, and the
elements of anchors[] were all
null.
- applets[] [ JavaScript 1.1]
-
An array of Applet objects, one for each applet that appears in the
document. You can use the Applet object to read and write all public
variables in the applet, and you can invoke all of the applet's
public methods. If an <applet> tag has a
name attribute, the applet may also be referred to
by using the name as a property of document or as
an index into the applets array. Thus, if the
first applet in a document has name="animator",
you can refer to it in any of these ways:
document.applets[0]
document.animator
document.applets["animator"]
- bgColor
-
A string property that specifies the background color of
document. The initial value of this
property comes from the bgcolor attribute of the
<body> tag. The background color may be
changed by assigning a value to bgColor. Unlike
the other color properties, bgColor can be set at
any time. See also the color properties of HTMLBodyElement in the DOM
reference section.
- cookie
-
A string that is the value of a cookie associated with this document.
See the Document.cookie reference page.
- domain
-
A string that specifies the document's Internet domain. Used
for security purposes. JavaScript 1.1 and higher. See the
Document.domain reference page.
- embeds[] [ JavaScript 1.1]
-
An array of objects that represent data embedded in the
document with the <embed> tag. The objects
in the embeds[] array do
not refer to the embedded data directly but refer instead to the
object that displays that data. You can use the objects in the
embeds[] array to interact with embedded data. The
way you do this, however, is specific to the type of embedded data
and the plugin or ActiveX control used to display it. Consult the
developer's documentation for the plugin or ActiveX control to
learn whether it can be scripted from JavaScript and, if so, what the
supported APIs are.
Document.plugins[] is a synonym for
Document.embeds[]. Do not confuse it with
Navigator.plugins[].
- fgColor
-
A string property that specifies the default color of
text in
document. The initial value of this
property is from the text attribute of the
<body> tag, and you can set the value of
this property from a script within the
<head> of the document. See also the color
properties of HTMLBodyElement in the DOM reference section.
- forms[]
-
An array of Form objects, one for each
HTML form that appears in document. The
forms[] array has forms.length
elements, numbered from zero to forms.length-1.
- images[] [ JavaScript 1.1]
-
An array
of Image objects, one for each image that is embedded in the
document with the HTML <img> tag. If the
name attribute is specified in the
<img> tag for an Image, a reference to that
image is also stored in a property of the Document object. This
property has the same name as the image. So if an image has a
name="toggle" attribute, you can refer to the
image with document.toggle.
- lastModified
-
A read-only string that specifies the date of the most recent change
to the document (as reported by the web server). See the
Document.lastModified reference page.
- linkColor
-
A string property that specifies the color of unvisited links in the
document. The value of this property is set by the
link attribute of the
<body> tag, and it may also be set by a
script in the <head> of the document. See
also the color properties of HTMLBodyElement in the DOM reference
section.
- links[]
-
An array
of Link objects, one for each hypertext link that appears in the
document. The links[] array has
links.length elements, numbered from zero to
links.length-1.
- location [Deprecated]
-
A Location object that contains the
complete URL of the current document; a synonym for the
Window.location property. In JavaScript 1.0, this
property was instead a read-only string object that served the same
purpose as the Document.URL property.
- plugins[] [ JavaScript 1.1]
-
A synonym for the
embeds[] array. Refers to an array of objects that
represent the plugins or ActiveX controls used to display embedded
data in a document. The embeds property is the
preferred way to access this array, since it avoids confusion with
the Navigator.plugins[] array.
- referrer
-
A
read-only string property that contains the URL of the document, if
any, from which the current document was reached. For example, if the
user follows a link in document A to document B, the
Document.referrer property in document B contains
the URL of document A. On the other hand, if the user types the URL
of document B directly and does not follow any link to get there, the
Document.referrer property for document B is an
empty string.
- title
-
A read-only string property that
specifies the title of the current document. The title is any text
that appears between the <title> and
</title> tags in the
<head> of the document.
- URL
-
A read-only string that specifies the URL of the document. See the
Document.URL reference page.
- vlinkColor
-
A string property that specifies the color of visited links in
document. The value of this property is
set by the vlink attribute of the
<body> tag, and you can also set it from a
script within the <head> of the document.
See also the color properties of HTMLBodyElement in the DOM reference
section.
Netscape Properties
- height [Netscape 4]
-
The height, in pixels, of the
document.
- layers[] [Netscape 4 only]
-
An array of Layer objects that represent the layers contained within
a document. Each Layer object contains its own subdocument,
accessible through the document property of the
Layer object. This property is available only in Netscape 4; it has
been discontinued in Netscape 6.
- width [Netscape 4]
-
The width, in pixels, of the document.
Internet Explorer Properties
- activeElement [IE 4]
-
A read-only property that refers to the input element within the
document that is currently active (i.e., has the input focus).
- all[] [IE 4]
-
An array of all elements within the document. See the
Document.all[] reference page.
- charset [IE 4]
-
The character set of the document.
- children[] [IE 4]
-
An array that contains the HTML elements, in source order, that are
direct children of the document. Note that this is different than the
all[] array that contains all elements in the
document, regardless of their position in the containment hierarchy.
- defaultCharset
[IE 4]
-
The default character set of the document.
- expando [IE 4]
-
This property, if set to false, prevents
client-side objects from being expanded. That is, it causes a runtime
error if a program attempts to set the value of a nonexistent
property of a client-side object. Setting expando
to false can sometimes catch bugs caused by
property misspellings, which can otherwise be difficult to detect.
This property can be particularly helpful for programmers who are
switching to JavaScript after becoming accustomed to case-insensitive
languages. Although expando works only in IE 4, it
can be set safely (if ineffectively) in Netscape.
- parentWindow [IE 4]
-
The window that contains the document.
- readyState
-
Specifies the loading status of a document. It has one of the
following four string values:
- uninitialized
-
The document has not started loading.
- loading
-
The document is loading.
- interactive
-
The document has loaded sufficiently for the user to interact with it.
- complete
-
The document is completely loaded.
Methods
Document inherits methods from HTMLElement and defines the following
methods. Netscape and IE both define a number of incompatible
Document methods that are used mostly for DHTML; they are listed
separately.
- clear( )
-
Erases the contents of the document. This method is deprecated in
JavaScript 1.1.
- close( )
-
Closes a document stream opened with the open( )
method.
- open( )
-
Opens a stream to which document contents may be written.
- write( )
-
Inserts the specified string or strings into the document currently
being parsed or into a document stream opened with open(
).
- writeln( )
-
Identical to write( ), except that it appends a
newline character to the output.
Netscape Methods
- captureEvents( )
-
Requests events of specified types.
- getSelection( )
-
Returns the currently selected document text.
- releaseEvents
-
Stops capturing specified event types.
- routeEvent( )
-
Routes a captured event to the next interested element. See
Window.routeEvent( ).
Internet Explorer Methods
- elementFromPoint( )
-
Returns the element located at a given (X-coordinate, Y-coordinate)
point.
Event Handlers
The <body> tag has onload
and onunload attributes. Technically, however, the
onload and onunload event
handlers belong to the Window object rather than the Document object.
See Window.onload and Window.onunload.
HTML Syntax
The Document object
obtains values for a number of its properties from attributes of the
HTML <body> tag. Also, the HTML contents of
a document appear between the <body> and
</body> tags:
<body
[ background="imageURL" ] // A background image for the document
[ bgcolor="color" ] // A background color for the document
[ text="color" ] // The foreground color for the document's text
[ link="color" ] // The color for unvisited links
[ alink="color" ] // The color for activated links
[ vlink="color" ] // The color for visited links
[ onload="handler" ] // JavaScript to run when the document is loaded
[ onunload="handler" ] // JavaScript to run when the document is unloaded
>
// HTML document contents go here
</body>
Description
The Document object represents the HTML document displayed in a
browser window or frame (or layer, in Netscape 4). The properties of
this object provide details about many aspects of the document, from
the colors of the text, background, and anchors, to the date on which
the document was last modified. The Document object also contains a
number of arrays that describe the contents of the document. The
links[] array contains one Link object for each
hypertext link in the document. Similarly, the
applets[] array contains one object for each Java
applet embedded in the document, and the forms[]
array contains one Form object for each HTML form that appears in the
document.
The write( ) method of the Document object is
especially notable. When invoked in scripts that are run while the
document is loading, you can call document.write(
) to insert dynamically generated HTML text into the
document.
See Chapter 14 for an overview of the Document
object and of many of the JavaScript objects to which it refers. See
Chapter 17 for an overview of the DOM standard.
See Also
Form, the document property of the Window object;
Chapter 14; Document, HTMLDocument, and
HTMLBodyElement in the DOM reference section
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