Expression

new Cesium.Expression(expression, defines)

An expression for a style applied to a Cesium3DTileset.

Evaluates an expression defined using the 3D Tiles Styling language.

Implements the StyleExpression interface.

Name Type Description
expression String optional The expression defined using the 3D Tiles Styling language.
defines Object optional Defines in the style.
Examples:
var expression = new Cesium.Expression('(regExp("^Chest").test(${County})) && (${YearBuilt} >= 1970)');
expression.evaluate(frameState, feature); // returns true or false depending on the feature's properties
var expression = new Cesium.Expression('(${Temperature} > 90) ? color("red") : color("white")');
expression.evaluateColor(frameState, feature, result); // returns a Cesium.Color object

Members

readonlyexpression : String

Gets the expression defined in the 3D Tiles Styling language.
Default Value: undefined

Methods

evaluate(frameState, feature, result) → Boolean|Number|String|RegExp|Cartesian2|Cartesian3|Cartesian4|Color

Evaluates the result of an expression, optionally using the provided feature's properties. If the result of the expression in the 3D Tiles Styling language is of type Boolean, Number, or String, the corresponding JavaScript primitive type will be returned. If the result is a RegExp, a Javascript RegExp object will be returned. If the result is a Cartesian2, Cartesian3, or Cartesian4, a Cartesian2, Cartesian3, or Cartesian4 object will be returned. If the result argument is a Color, the Cartesian4 value is converted to a Color and then returned.
Name Type Description
frameState FrameState The frame state.
feature Cesium3DTileFeature The feature whose properties may be used as variables in the expression.
result Object optional The object onto which to store the result.
Returns:
The result of evaluating the expression.

evaluateColor(frameState, feature, result) → Color

Evaluates the result of a Color expression, optionally using the provided feature's properties.

This is equivalent to Expression#evaluate but always returns a Color object.

Name Type Description
frameState FrameState The frame state.
feature Cesium3DTileFeature The feature whose properties may be used as variables in the expression.
result Color optional The object in which to store the result
Returns:
The modified result parameter or a new Color instance if one was not provided.