• esri/form

ExpressionInfo

AMD: require(["esri/form/ExpressionInfo"], (ExpressionInfo) => { /* code goes here */ });
ESM: import ExpressionInfo from "@arcgis/core/form/ExpressionInfo";
Class: esri/form/ExpressionInfo
Inheritance: ExpressionInfo Accessor
Since: ArcGIS Maps SDK for JavaScript 4.16

The ExpressionInfo class defines the makeup of visibility expressions, required expressions, editable expressions, and value expressions. Expressions are set on field elements, (visibility expressions also being available on group elements). These elements are contained within a formTemplate set directly on either a FeatureForm or FeatureLayer.

All of the Arcade expressions referenced above, excluding value expressions, must follow the specification defined in the Constraint Profile. This profile may reference field values using the $feature variable and the expression must return true or false.

Value expressions must follow the specification defined in the Form Calculation Profile. It may reference field values within an individual $feature or in other layers and must return either a date, number, or string value. Once the expression evaluates, the form's field value updates to the expressions' result.

It is required to set the view property when instantiating a FeatureForm widget and using expressions that use the $map variable.

See also

Constructors

new ExpressionInfo(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

An Arcade expression following the specification defined by the Constraint or Form Calculation profiles.

more details
ExpressionInfo
String

The name of the expression.

more details
ExpressionInfo
String

Indicates the return type of the Arcade expression.

more details
ExpressionInfo
String

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

more details
ExpressionInfo

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 Constraint or Form Calculation profiles. Visibility expressions, required expressions, and editable expressions follow the specification defined in the Constraint profile. These expressions may reference field values using the $feature profile variable and must return either true or false.

Value expressions adhere to the specification defined in the Form Calculation profile. The available profile variables when working with value expressions extend beyond just $feature since it is also possible to access values beyond the individual feature that is being displayed.

See also
Example
// Sets the visibility of a field in the form template only if the date is within the last 24 hours.
expressionInfo.expression = "IIF(DateDiff(Now(), $feature.incident_date, 'hours') < 24)";
name String

The name of the expression. Set this name to the visibility expression, required expression, editable expression, and/or value expression properties of its respective elements.

Example
expressionInfo.name = "withinRange";
returnType String

Indicates the return type of the Arcade expression. In FeatureForm expressions, the returnType can be boolean, date, number or string. This is dependant upon the type of expression used. For example, visibility expressions, required expressions, and editable expressions only return a boolean, whereas value expressions return either date, number, or string.

Possible Values:"boolean"|"date"|"number"|"string"

See also
title String

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

Example
expressionInfo.title = "Did the incident occur within the last 24 hours?";

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
ExpressionInfo

Creates a deep clone of the ExpressionInfo class.

more details
ExpressionInfo
*

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

more details
ExpressionInfo
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
ExpressionInfo

Method Details

addHandles(handleOrHandles, groupKey)inherited
Since: ArcGIS Maps SDK 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(){ExpressionInfo}

Creates a deep clone of the ExpressionInfo class.

Returns
Type Description
ExpressionInfo A deep clone of the ExpressionInfo instance.
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 Maps SDK 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 Maps SDK 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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