ExpressionInfo | References | ArcGIS Maps SDK for JavaScript

import ExpressionInfo from "@arcgis/core/popup/ExpressionInfo.js";

Inheritance:: ExpressionInfo→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.11

The ExpressionInfo class references Arcade expressions following the specification defined by the Arcade Popup Profile. Expressions must return a string or a number and may access data values from the feature, its layer, or other layers in the map or datastore with the $feature, $layer, $map, and $datastore profile variables.

Expression names are referenced in a layer's PopupTemplate and execute once a layer's popup is opened. The values display within the view's popup as if they are field values. They can be displayed in a table using the FieldInfo of the popupTemplate's content or referenced within a simple string.

See also

Example

// Display a table in the popup's content referencing two values
// one from a field, and another returned from an Arcade expression
layer.popupTemplate = {
  title: "Population in {NAME}",
  content: [{
    type: "fields",
    fieldInfos: [{
      fieldName: "POP_2015",
      label: "Total population (2015)",
      format: {
        digitSeparator: true
      }
    }, {
      fieldName: "expression/per-asian"
    }]
  }]
};

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`ExpressionInfoProperties`

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

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.

Property	Type	Class
`declaredClass` readonly inherited	`string`	Accessor
`expression`	`string`
`name`	`string`
`returnType`	`"string" \| "number"`
`title`	`string \| null \| undefined`

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

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

expression

Property

Type: string

An Arcade expression following the specification defined by the Arcade Popup Profile. Expressions must return a string or a number and may access data values from the feature, its layer, or other layers in the map or datastore with the $feature, $layer, $map, and $datastore profile variables.

See also

Example

// Calculates the percentage of the population that is Asian
expressionInfo.expression = "Text($feature.Asian / $feature.TOT_POP, '#.#%')";

name

Property

Type: string

The name of the expression. This is used to reference the value of the given expression in the popupTemplate's PopupTemplate.content property by wrapping it in curly braces and prefacing it with expression/ (e.g. {expression/expressionName}).

Example

expressionInfo.name = "percent-asian";

returnType

Property

Type: "string" | "number"

Indicates the return type of the Arcade expression.

title

Property

Type: string | null | undefined

The title used to describe the value returned by the expression in the popup. This will display if the value is referenced in a FieldInfo table.

Example

expressionInfo.title = "Percent Asian";

Methods

Method	Signature	Class
`fromJSON` inherited static	`fromJSON(json: any): any`	JSONSupportMixin
`clone`	`clone(): ExpressionInfo`
`toJSON` inherited	`toJSON(): any`	JSONSupportMixin

fromJSON

inheritedstatic Method

Signature: fromJSON (json: any): any

Inherited from: JSONSupportMixin

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.

Parameters

Parameter	Type	Description	Required
json	`any`	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: any
Returns a new instance of this class.

clone

Method

Signature: clone (): ExpressionInfo

Creates a deep clone of the ExpressionInfo class.

Returns: ExpressionInfo
A deep clone of the ExpressionInfo instance.

toJSON

inherited Method

Signature: toJSON (): any

Inherited from: JSONSupportMixin

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

Returns: any
The ArcGIS portal JSON representation of an instance of this class.