fieldUtils | References | ArcGIS Maps SDK for JavaScript

import { getDisplayFieldName, getElevationFields, getTimeFields, getFeatureEditFields, getFeatureGeometryFields } from "@arcgis/core/layers/support/fieldUtils.js";

Since: ArcGIS Maps SDK for JavaScript 4.11

Convenience methods for getting field names used for feature layer labeling, elevation, editor tracking and time span.

Functions

Name	Return Type	Object
`getDisplayFieldName`	`string \| null \| undefined`
`getElevationFields`	`Promise<string[]>`
`getTimeFields`	`Promise<string[]>`
`getFeatureEditFields`	`string[]`
`getFeatureGeometryFields`	`string[]`
`getLabelingFields`	`Promise<string[]>`
`FieldValue`
`getExpressionFields`	`Promise<string[]>`
`getRendererFields`	`Promise<string[]>`

getDisplayFieldName

Function

Since: ArcGIS Maps SDK for JavaScript 4.15

Gets the appropriate display field name to label a feature.

Signature: getDisplayFieldName (layer: FeatureLayer | CSVLayer | GeoJSONLayer | OGCFeatureLayer | SceneLayer | StreamLayer): string | null | undefined

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| CSVLayer \| GeoJSONLayer \| OGCFeatureLayer \| SceneLayer \| StreamLayer`	An array of fields to determine the display field from.

Returns: string | null | undefined
The name of the display field to use for labeling.

getElevationFields

Function

Returns an array of field names used in the Arcade expression for calculating the z-values of features in the given feature layer's FeatureLayer.elevationInfo.

Signature: getElevationFields (layer: FeatureLayer | null | undefined): Promise<string[]>

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| null \| undefined`	The featureLayer to extract fields required for calculating feature z-values.

Returns: Promise<string[]>
When resolved, returns an array of field names.

getTimeFields

Function

Returns an array of field names related to time. It includes the fields from the FeatureLayer.timeInfo, and the trackIdField.

Signature: getTimeFields (layer: FeatureLayer | null | undefined): Promise<string[]>

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| null \| undefined`	The Feature Layer from which to extract time fields.

Returns: Promise<string[]>
When resolved, returns an array of time field names.

getFeatureEditFields

Function

Returns an array of editor tracking field names for a given layer. It includes the fields from the FeatureLayer.editFieldsInfo.

Signature: getFeatureEditFields (layer: FeatureLayer | SubtypeGroupLayer): string[]

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| SubtypeGroupLayer`	The layer from which to extract editor tracking fields.

Returns: string[]
An array of field names used for editor tracking.

getFeatureGeometryFields

Function

Since: ArcGIS Maps SDK for JavaScript 4.19

Returns an array of geometry field names for a given layer.

Signature: getFeatureGeometryFields (layer: FeatureLayer | SubtypeGroupLayer): string[]

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| SubtypeGroupLayer`	The layer to extract geometry fields from.

Returns: string[]
An array of geometry field names.

getLabelingFields

Function

Returns an array of field names used in the Arcade expression for labeling features in the given feature layer's FeatureLayer.labelingInfo.

Signature: getLabelingFields (layer: FeatureLayer | null | undefined): Promise<string[]>

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| null \| undefined`	The Feature Layer from which to extract label fields.

Returns: Promise<string[]>
When resolved, returns an array of field names used for labeling.

getExpressionFields

Function

Since: ArcGIS Maps SDK for JavaScript 4.15

Returns an array of field names referenced in one or more Arcade expressions to be set on the given layer in either the renderer, labels, or popup template. This is useful for when you want to request the data for these fields prior to updating a renderer for fast visual updates or when you want to execute a client-side query on that data prior to setting the Arcade expressions on the layer.

See also

Arcade - expression language

Signature: getExpressionFields (layer: FeatureLayer | CSVLayer | GeoJSONLayer | SceneLayer | StreamLayer, expressions: string[]): Promise<string[]>

Parameters

Parameter	Type	Description	Required
layer	`FeatureLayer \| CSVLayer \| GeoJSONLayer \| SceneLayer \| StreamLayer`	The layer for which the Arcade `expressions` are authored. This layer must have a `fields` property.
expressions	`string[]`	An array of Arcade expressions to be set on the given `layer`.

Returns: Promise<string[]>
Returns an array of field names declared either by the $feature.fieldName or $feature[fieldName] syntax.

Example

const windDirectionExpression = `
  $feature["WIND_DIRECT"];
  $feature["WIND_SPEED"];
  var DEG = $feature.WIND_DIRECT;
  var SPEED = $feature.WIND_SPEED;
  var DIR = When( SPEED == 0, "",
    (DEG < 22.5 && DEG >= 0) || DEG > 337.5, "N",
    DEG >= 22.5 && DEG < 67.5, "NE",
    DEG >= 67.5 && DEG < 112.5, "E",
    DEG >= 112.5 && DEG < 157.5, "SE",
    DEG >= 157.5 && DEG < 202.5, "S",
    DEG >= 202.5 && DEG < 247.5, "SW",
    DEG >= 247.5 && DEG < 292.5, "W",
    DEG >= 292.5 && DEG < 337.5, "NW", "" );
  return SPEED + " mph " + DIR;
`;

const labelExpressions = [
  "Round($feature.TEMP) + '° F';",
  "$feature.R_HUMIDITY + '% RH'",
  "$feature.STATION_NAME",
  windDirectionExpression
];

// Assume the layer has only requested the OBJECTID field
fieldUtils.getExpressionFields(layer, labelExpressions)
 .then(function(fieldNames){

  // fieldNames = ["R_HUMIDITY", "STATION_NAME", "TEMP", "WIND_DIRECT", "WIND_SPEED"]
  layer.outFields = fieldNames;

  // Do something else like a client-side query with those fields
 }).catch(function(error){
   console.error(error);
 });

getRendererFields

Function

Since: ArcGIS Maps SDK for JavaScript 4.30

Returns an array of field names used in the layer's Renderer.

Signature: getRendererFields (renderer: RendererUnion | null | undefined, fieldsIndex: FieldsIndex<Field>): Promise<string[]>

Parameters

Parameter	Type	Description	Required
renderer	`RendererUnion \| null \| undefined`	Layer's renderer to collect field names used in that renderer.
fieldsIndex	`FieldsIndex<Field>`	The field index of the layer. It can be used to make case-insensitive lookups for a field by name.

Returns: Promise<string[]>
When resolved, returns an array of field names required by the layer's renderer, sorted in ascending order.

Example

const rendererFields = fieldUtils.getRendererFields(layer.renderer, layer.fieldsIndex);

Type definitions

FieldValue

Type definition

Value from a specified field.

Type: null | undefined | string | number