fieldUtils

AMD: require(["esri/layers/support/fieldUtils"], (fieldUtils) => { /* code goes here */ });
ESM: import * as fieldUtils from "@arcgis/core/layers/support/fieldUtils";
Object: esri/layers/support/fieldUtils
Since: ArcGIS API for JavaScript 4.11

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

Method Overview

Name Return Type Summary Object
String

Gets the appropriate display field name to label a feature.

more details
fieldUtils
Promise<string[]>

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.

more details
fieldUtils
Promise<string[]>

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.

more details
fieldUtils
String[]

Returns an array of editor tracking field names for a given feature layer.

more details
fieldUtils
String[]

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

more details
fieldUtils
Promise<string[]>

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

more details
fieldUtils
Promise<string[]>

Returns an array of field names related to time.

more details
fieldUtils

Method Details

getDisplayFieldName(layer){String}
Since: ArcGIS API for JavaScript 4.15

Gets the appropriate display field name to label a feature.

Parameter

An array of fields to determine the display field from.

Returns
Type Description
String The name of the display field to use for labeling.
getElevationFields(layer){Promise<string[]>}

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.

Parameter
layer FeatureLayer

The featureLayer to extract fields required for calculating feature z-values.

Returns
Type Description
Promise<string[]> When resolved, returns an array of field names.
getExpressionFields(layer, expressions){Promise<string[]>}
Since: ArcGIS API 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.

Parameters

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
Type Description
Promise<string[]> Returns an array of field names declared either by the $feature.fieldName or $feature[fieldName] syntax.
See also
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);
 });
getFeatureEditFields(layer){String[]}

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

Parameter
layer FeatureLayer

The Feature Layer from which to extract editor tracking fields.

Returns
Type Description
String[] An array of field names used for editor tracking.
getFeatureGeometryFields(layer){String[]}
Since: ArcGIS API for JavaScript 4.19

Returns an array of geometry field names for a given feature layer. It includes the fields from the FeatureLayer.geometryProperties.

Parameter
layer FeatureLayer

The featureLayer to extract geometry fields from.

Returns
Type Description
String[] An array of geometry field names.
getLabelingFields(layer){Promise<string[]>}

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

Parameter
layer FeatureLayer

The Feature Layer from which to extract label fields.

Returns
Type Description
Promise<string[]> When resolved, returns an array of field names used for labeling.
getTimeFields(layer){Promise<string[]>}

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

Parameter
layer FeatureLayer

The Feature Layer from which to extract time fields.

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

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