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getExpression

Method of css/cssom/methodscss/cssom/methods

Syntax

var object = object.getExpression(PropertyName);

Parameters

PropertyName

Data-type
String

String that specifies the name of the property from which to retrieve the expression.

Return Value

Returns an object of type DOM NodeDOM Node

A variant value representing the expression of the property.

Examples

The following examples demonstrate how to use the getExpression method to retrieve CSS properties. This example retrieves the width property of a span object.

<body>
<span id="trueBlueSpan"
    style="background-color:lightblue; width:100px">
    The width of this blue span is set inline at 100 pixels.
</span>
<span id="oldYellowSpan" style="background-color:lightyellow;
    width:200px">
    The width of this yelllow span is set inline at 200 pixels.
</span>
<br>
<span id="AlGreenSpan" style="background-color:lightgreen;
    width:expression(trueBlueSpan.style.pixelWidth +
    oldYellowSpan.style.pixelWidth)">
    Click the button below to see the expression used to set
    the width of this span.
</span>
<br>
<button onclick=alert(AlGreenSpan.style.getExpression("width"));>
    See Expression</button>
</body>

In the following example, the setExpression method is used to set the width property of a blue input type=text object equal to the sum of the values in two other input type=text objects. When the user clicks the input type=button element, the getExpression method is used to display the expression.

<html>
<head>
<script language="JScript">
var s;
function fnInit() {
Box3.style.setExpression("width","eval(Box1.value) + eval(Box2.value)",
"jscript");
}
function getexp() {
s=Box3.style.getExpression("width");
alert("Expression for the width of the blue box is \n\n" + s +
"\n\nThe width property has a value of " + Box3.style.width);
}
</script>
</head>
<body onload=fnInit();>
<input type=text id="Box1" value=40>
<br><input type=text id="Box2" value=40>
<br><input type=text id="Box3" style="background-color:blue">
<br><input type=button id="Button2" value="Get expression" onclick="getexp()">
</body>
</html>

View live example

Notes

Remarks

The following syntax sections show how to retrieve an expression from supported Cascading Style Sheets (CSS) and DHTML Properties.

  • Use this syntax to retrieve an expression from a read/write property or from an expando property.

var sExpression = object.getExpression(sPropertyName)

  • Use this syntax to retrieve an expression from a CSS attribute.

var sExpression = object.style.getExpression(sPropertyName)

See also

Related pages

Attributions