CSSStyleDeclaration

Summary

CSSStyleDeclaration represents a collection of CSS property-value pairs. It is used in a few APIs:

HTMLElement.style - to manipulate the style of a single element (<elem style="...">);
(TODO: reword) is an interface to the declaration block returned by the style property of a cssRule in a stylesheet, when the rule is a CSSStyleRule.
CSSStyleDeclaration is also a read-only interface to the result of window.getComputedStyle().

Attributes

CSSStyleDeclaration.cssText: Textual representation of the declaration block. Setting this attribute changes the style.
CSSStyleDeclaration.length: The number of properties. See the item method below.
CSSStyleDeclaration.parentRule: The containing CssRule.

Methods

CSSStyleDeclaration.getPropertyPriority(): Returns the optional priority, "important". Example: priString= styleObj.getPropertyPriority('color')
CSSStyleDeclaration.getPropertyValue(): Returns the property value. Example: valString= styleObj.getPropertyValue('color')
CSSStyleDeclaration.item(): Returns a property name. Example: nameString= styleObj.item(0) Alternative: nameString= styleObj[0]
CSSStyleDeclaration.removeProperty(): Returns the value deleted. Example: valString= styleObj.removeProperty('color')
CSSStyleDeclaration.setProperty(): No return. Example: styleObj.setProperty('color', 'red', 'important')
CSSStyleDeclaration.getPropertyCSSValue(): Only supported via getComputedStyle. Returns an ROCSSPrimitiveValue in Firefox (CSSPrimitiveValue, in others, which implements CSSValue), or null for Shorthand properties. Example: cssString= window.getComputedStyle(elem, null).getPropertyCSSValue('color').cssText;
Note: Gecko 1.9 returns null unless using getComputedStyle().
Note: This method may be deprecated by the W3C , and it is not present in the latest CSSOM draft. It is not supported by IE and even though the function exists in Opera, calling it throws a DOMException NOT_SUPPORTED_ERR.

Example

var styleObj= document.styleSheets[0].cssRules[0].style;
alert(styleObj.cssText);
for (var i = styleObj.length-1; i >= 0; i--) {
   var nameString = styleObj[i];
   styleObj.removeProperty(nameString);
}
alert(styleObj.cssText);

Notes

The declaration block is that part of the style rule that appears within the braces and that actually provides the style definitions (for the selector, the part that comes before the braces).

Specification

CSSOM: CSSStyleDeclaration