CSSPrimitiveValue - Web APIs 编辑

The CSSPrimitiveValue interface derives from the CSSValue interface and represents the current computed value of a CSS property.

This interface represents a single CSS value. It may be used to determine the value of a specific style property currently set in a block or to set a specific style property explicitly within the block. An instance of this interface might be obtained from the getPropertyCSSValue() method of the CSSStyleDeclaration interface. A CSSPrimitiveValue object only occurs in a context of a CSS property.

Conversions are allowed between absolute values (from millimeters to centimeters, from degrees to radians, and so on) but not between relative values. (For example, a pixel value cannot be converted to a centimeter value.) Percentage values can't be converted since they are relative to the parent value (or another property value). There is one exception for color percentage values: since a color percentage value is relative to the range 0-255, a color percentage value can be converted to a number (see also the RGBColor interface).

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Properties

Inherits properties from its parent, CSSValue.

CSSPrimitiveValue.primitiveType Read only

An unsigned short representing the type of the value. Possible values are:

Constant	Description
CSS_ATTR	The value is an attr()() function. The value can be obtained by using the getStringValue() method.
CSS_CM	The value is a <length> in centimeters. The value can be obtained by using the getFloatValue() method.
CSS_COUNTER	The value is a counter or counters function. The value can be obtained by using the getCounterValue() method.
CSS_DEG	The value is an <angle> in degrees. The value can be obtained by using the getFloatValue() method.
CSS_DIMENSION	The value is a <number> with an unknown dimension. The value can be obtained by using the getFloatValue() method.
CSS_EMS	The value is a <length> in em units. The value can be obtained by using the getFloatValue() method.
CSS_EXS	The value is a <length> in ex units. The value can be obtained by using the getFloatValue() method.
CSS_GRAD	The value is an <angle> in grads. The value can be obtained by using the getFloatValue() method.
CSS_HZ	The value is a <frequency> in Hertz. The value can be obtained by using the getFloatValue method.
CSS_IDENT	The value is an identifier. The value can be obtained by using the getStringValue() method.
CSS_IN	The value is a <length> in inches. The value can be obtained by using the getFloatValue() method.
CSS_KHZ	The value is a <frequency> in Kilohertz. The value can be obtained by using the getFloatValue() method.
CSS_MM	The value is a <length> in millimeters. The value can be obtained by using the getFloatValue() method.
CSS_MS	The value is a <time> in milliseconds. The value can be obtained by using the getFloatValue() method.
CSS_NUMBER	The value is a simple <number>. The value can be obtained by using the getFloatValue() method.
CSS_PC	The value is a <length> in picas. The value can be obtained by using the getFloatValue() method.
CSS_PERCENTAGE	The value is a <percentage>. The value can be obtained by using the getFloatValue() method.
CSS_PT	The value is a <length> in points. The value can be obtained by using the getFloatValue() method.
CSS_PX	The value is a <length> in pixels. The value can be obtained by using the getFloatValue() method.
CSS_RAD	The value is an <angle> in radians. The value can be obtained by using the getFloatValue() method.
CSS_RECT	The value is a rect() function. The value can be obtained by using the getRectValue() method.
CSS_RGBCOLOR	The value is an <color>. The value can be obtained by using the getRGBColorValue() method.
CSS_S	The value is a <time> in seconds. The value can be obtained by using the getFloatValue() method.
CSS_STRING	The value is a <string>. The value can be obtained by using the getStringValue() method.
CSS_UNKNOWN	The value is not a recognized CSS2 value. The value can only be obtained by using the cssText attribute.
CSS_URI	The value is a <uri>(). The value can be obtained by using the getStringValue() method.

Methods

CSSPrimitiveValue.getCounterValue()

This method is used to get the counter value. If this CSS value doesn't contain a counter value, a DOMException is raised. Modification to the corresponding style property can be achieved using the Counter interface.

CSSPrimitiveValue.getFloatValue()

This method is used to get a float value in a specified unit. If this CSS value doesn't contain a float value or can't be converted into the specified unit, a DOMException is raised.

CSSPrimitiveValue.getRGBColorValue()

This method is used to get the RGB color. If this CSS value doesn't contain a RGB color value, a DOMException is raised. Modification to the corresponding style property can be achieved using the RGBColor interface.

CSSPrimitiveValue.getRectValue()

This method is used to get the Rect value. If this CSS value doesn't contain a rect value, a DOMException is raised. Modification to the corresponding style property can be achieved using the Rect interface.

CSSPrimitiveValue.getStringValue()

This method is used to get the string value. If the CSS value doesn't contain a string value, a DOMException is raised.

CSSPrimitiveValue.setFloatValue()

A method to set the float value with a specified unit. If the property attached with this value can not accept the specified unit or the float value, the value will be unchanged and a DOMException will be raised.

CSSPrimitiveValue.setStringValue()

A method to set the string value with the specified unit. If the property attached to this value can't accept the specified unit or the string value, the value will be unchanged and a DOMException will be raised.

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• CSSValue
• CSSValueList