OpacityVariable

AMD: require(["esri/renderers/visualVariables/OpacityVariable"], (OpacityVariable) => { /* code goes here */ });
ESM: import OpacityVariable from "@arcgis/core/renderers/visualVariables/OpacityVariable";
Class: esri/renderers/visualVariables/OpacityVariable
Inheritance: OpacityVariable VisualVariable Accessor
Since: ArcGIS API for JavaScript 4.10

The opacity visual variable defines the opacity of each feature's symbol based on a numeric field value or number returned from an expression. You must specify stops to construct the opacity ramp.

renderer-vv-opacity

See also
Examples
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 ];

Constructors

new OpacityVariable(properties)
Parameter
properties Object
optional

See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
Show inherited properties Hide inherited properties
Name Type Summary Class
String

The name of the class.

more details
Accessor
String

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

more details
VisualVariable
Object

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

more details
VisualVariable
String

Name of the numeric attribute field by which to normalize the data.

more details
OpacityVariable
OpacityStop[]

An array of objects that defines the opacity to apply to features in a layer in a sequence of stops.

more details
OpacityVariable
String

The visual variable type.

more details
OpacityVariable
String

An Arcade expression following the specification defined by the Arcade Visualization Profile.

more details
VisualVariable
String

The title identifying and describing the associated Arcade expression as defined in the valueExpression property.

more details
VisualVariable

Property Details

declaredClass Stringreadonly inherited

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

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

legendOptions Object 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.

normalizationField String

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.

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.

type Stringreadonly

The visual variable type.

For OpacityVariable the type is always "opacity".

valueExpression String inherited

An Arcade expression following the specification defined by the Arcade Visualization Profile. Expressions in visual variables may reference field values using the $feature profile variable and must return a number.

The values returned from this expression are the data used to drive the visualization as defined in the stops. This takes precedence over field. Therefore, this property is typically used as an alternative to field in visual variables.

See also
valueExpressionTitle String 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

Show inherited methods Hide inherited methods
Name Return Type Summary Class

Adds one or more handles which are to be tied to the lifecycle of the object.

more details
Accessor
OpacityVariable

Creates a deep clone of the OpacityVariable.

more details
OpacityVariable
*

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.

more details
OpacityVariable
Boolean

Returns true if a named group of handles exist.

more details
Accessor

Removes a group of handles owned by the object.

more details
Accessor
Object

Converts an instance of this class to its ArcGIS portal JSON representation.

more details
OpacityVariable

Method Details

addHandles(handleOrHandles, groupKey)inherited
Since: ArcGIS API for JavaScript 4.25

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

// Handle gets removed when the object is destroyed.
this.addHandles(handle);
Parameters
handleOrHandles WatchHandle|WatchHandle[]

Handles marked for removal once the object is destroyed.

groupKey *
optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

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
let 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 an ArcGIS product. 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.
hasHandles(groupKey){Boolean}inherited
Since: ArcGIS API for JavaScript 4.25

Returns true if a named group of handles exist.

Parameter
groupKey *
optional

A group key.

Returns
Type Description
Boolean Returns true if a named group of handles exist.
Example
// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}
removeHandles(groupKey)inherited
Since: ArcGIS API for JavaScript 4.25

Removes a group of handles owned by the object.

Parameter
groupKey *
optional

A group key or an array or collection of group keys to remove.

Example
obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");
toJSON(){Object}

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

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

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