IHTMLStyle2::getExpression method

This element is obsolete and should no longer be used. Retrieves the expression for the given property.

Syntax

C++
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Variant* getExpression(
  [in] String sPropertyName
);

Parameters

sPropertyName [in]

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

Return value

C++

a variant value representing the expression of the property.

JavaScript

a variant value representing the expression of the property.

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.
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var sExpression = object.getExpression(sPropertyName)
  • Use this syntax to retrieve an expression from a CSS attribute.
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var sExpression = object.style.getExpression(sPropertyName)

Examples

The following examples demonstrate how to use the getExpression method to retrieve CSS properties.

This example uses the getExpression method to retrieve the width property of a span object.

JavaScript
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<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.

Code example: http://samples.msdn.microsoft.com/workshop/samples/author/dhtml/refs/getExpression.htm

JavaScript
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<html>
<head>
<script type="text/javascript">
var s;
function fnInit() {
Box3.style.setExpression("width","eval(Box1.value) + eval(Box2.value)",
"javascript");
}
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>

See also

IHTMLStyle2
IHTMLElement2
currentStyle
runtimeStyle
style
Reference
recalc
removeExpression
setExpression
Conceptual
CSS Attributes: Index
About Dynamic Properties

 

 

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