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

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DOM Level 2 CSS

Also Implements

If the implementation supports the "CSS2" feature in
addition to the "CSS" feature (as most web browsers do),
all objects that implement this interface also implement the
CSS2Properties interface. CSS2Properties provides commonly used
shortcut properties for setting and querying the values of CSS
attributes. See CSS2Properties for details.

Properties

String cssText

The textual
representation of the style attributes and their values. This
property consists of the complete text of the style rule, minus the
element selector and the curly braces that surround the attributes
and values. Setting this property to an illegal value throws a
DOMException with a code of
SYNTAX_ERR. Setting it for a read-only style sheet
or rule throws a DOMException with a code of
NO_MODIFICATION_ALLOWED_ERR.

readonly unsigned long length

The number
of style attributes in this style declaration.

readonly

CSSRule

parentRule

The
CSSRule object that contains this CSSStyleDeclaration, or
null if this style declaration is not part of a
CSS rule (such as for CSSStyleDeclaration objects that represent
inline HTML style attributes).

Methods

getPropertyCSSValue( )

Returns a CSSValue object that represents the value of the named CSS
attribute, or null if that attribute is not
explicitly set in this style declaration block or if the named style
is a "shortcut" attribute.

getPropertyPriority( )

Returns the string "important" if the named CSS attribute
is explicitly set in this declaration block and has the
!important priority qualifier specified. If the
attribute is not specified, or has no priority, returns the empty
string.

getPropertyValue( )

Returns the value of the named CSS attribute as a string. Returns the
empty string if the attribute is not specified in this declaration
block.

item( )

Returns the name of the CSS attribute at the specified position in
this style declaration block. In JavaScript, the CSSStyleDeclaration
object can be treated as an array and indexed using square brackets
instead. See also the length property.

removeProperty( )

Deletes a named CSS attribute from this declaration block.

setProperty( )

Sets a named CSS attribute to the specified string value and priority
for this declaration block.

Description

This attribute represents a CSS style declaration
block: a set of CSS attributes and their values,
separated from each other by semicolons. The style declaration block
is the portion of a style rule within curly braces in a CSS style
sheet. The value of the HTML style attribute also
constitutes a style declaration block.

The item( ) method and the
length property allow you to loop through the
names of all CSS attributes specified in this declaration block. In
JavaScript, you can also simply treat the CSSStyleDeclaration object
as an array and index it using square-bracket notation instead of
calling the item( ) method explicitly. Once you
have the names of the CSS attributes specified in this declaration,
you can use other methods of this interface to query the values of
those attributes. getPropertyValue( ) returns the
value as a string, and getPropertyCSSValue( )
returns the attribute value as a CSSValue object. (Note that the DOM
API refers to CSS style attributes as "properties." I use
the term "attributes" here to avoid confusing them with
JavaScript object properties.)

In most web browsers, every object that implements
CSSStyleDeclaration also implements the CSS2Properties interface,
which defines an object property for each CSS attribute defined by
the CSS2 specification. You can read and write the values of these
convenience properties instead of calling getPropertyValue(
) and setProperty( ).

See Also

CSS2Properties

Type of

CSSFontFaceRule.style, CSSPageRule.style, CSSStyleRule.style,
HTMLElement.style

Returned by

Document.getOverrideStyle( ), AbstractView.getComputedStyle( )