const opacityVisualVariable = {
  type: "opacity",
  field: "PERCENTAGE",
  // maps data values to opacity values
  stops: [
    { value: 0, opacity: 0.1 },
    { value: 100, opacity: 1 }
  ]
};
renderer.visualVariables = [ opacVisVar ];

// opacity visual variable with arcade
const opacityVisualVariable = {
  type: "opacity",
  // calculate a value to visualize with opacity
  valueExpression: "( $feature.TOT_VOTES / $feature.REG_VOTERS ) * 100",
  stops: [
    { value: 30, opacity: 0.15 },
    { value: 70, opacity: 0.15 }
  ]
};
renderer.visualVariables = [ opacityVisVar ];

Property Overview

Property Details

declaredClassStringreadonly inherited

The name of the class. The declared class name is formatted as esri.folder.className.

fieldString inherited

The name of the numeric attribute field that contains the data values used to determine the color/opacity/size/rotation of each feature.

indexString|Number inherited

The index of the visual variable in relation to its position in the visualVariables property of the renderer.

legendOptionsObject inherited

An object providing options for displaying the visual variable in the Legend.

Properties:

showLegend Boolean optional Indicates whether to show the visual variable in the legend.

title String optional The title describing the visualization of the visual variable in the Legend. This takes precedence over a field alias or valueExpressionTitle.

normalizationFieldString

Name of the numeric attribute field by which to normalize the data. If this field is used, then the values in stops should be normalized as percentages or ratios.

stopsOpacityStop[]autocast

Autocasts from Object[]

An array of objects that defines the opacity to apply to features in a layer in a sequence of stops. You must specify 2 - 8 stops. In most cases, no more than five are needed. Features with data values that fall between the given stops will be assigned opacity values linearly interpolated along the ramp in relation to the stop values. The stops must be listed in ascending order based on the value of the value property in each stop.

typeStringreadonly

The visual variable type. For OpacityVariable, this value is always opacity.

valueExpressionString inherited

An Arcade expression evaluating to a number. This expression can reference field values using the $feature global variable and perform mathematical calculations and logical evaluations at runtime. The values returned from this expression are the data used to drive the visualization. This takes precedence over field. Therefore, this property is typically used as an alternative to field in visual variables.

See also:

• Arcade - expression language

valueExpressionTitleString inherited

The title identifying and describing the associated Arcade expression as defined in the valueExpression property. This is displayed as the title of the corresponding visual variable in the Legend in the absence of a provided title in the legendOptions property.

Method Overview

Method Details

clone(){OpacityVariable}

Creates a deep clone of the OpacityVariable.

Returns:

Type	Description
OpacityVariable	A deep clone of the opacity visual variable that invoked this method.

Example:

// Creates a deep clone of the visual variable
var renderer = renderer.visualVariables[0].clone();

fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from a product in the ArcGIS platform. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter:

json Object A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns:

Type	Description
*	Returns a new instance of this class.

toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() topic in the Guide for more information.

Returns:

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.