ExpressionInfo

const expressionInfo = new ExpressionInfo({
  title: "Population per square kilometer",
  returnType: "number",
  expression: "$feature.population / AreaGeodetic($feature, 'square-kilometers')"
});

Property Overview

Property Details

declaredClass Stringreadonly inherited

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

expression String

An Arcade expression following the specification defined by the Arcade Visualization Profile. Expressions must return a string or a number and may access data values from the feature with the $feature profile variable.

See also

• Arcade Visualization Profile

Example

// Calculates the percentage of the population that is Asian
expressionInfo.expression = "($feature.Asian / $feature.TOT_POP) * 100";

returnType String

Indicates the return type of the Arcade expression.

Possible Values:"string"|"number"

title String

The title used to describe the value returned by the expression.

Example

expressionInfo.title = "Percent Asian";

Method Overview

Method Details

addHandles(handleOrHandles, groupKey)inherited

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 }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

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(){this}

Creates a deep clone of this object. Any properties that store values by reference will be assigned copies of the referenced values on the cloned instance.

Returns

Type	Description
this	A deep clone of the class instance that invoked this method.

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

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

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.