fieldUtils | API Reference | ArcGIS Maps SDK for JavaScript 4.32

Method Overview

Return Type	Summary	Object
String\|null\|undefined	Gets the appropriate display field name to label a feature.	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.	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.	fieldUtils
String []	Returns an array of editor tracking field names for a given layer.	fieldUtils
String []	Returns an array of geometry field names for a given layer.	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.	fieldUtils
Promise<String []>	Returns an array of field names used in the layer's Renderer.	fieldUtils
Promise<String []>	Returns an array of field names related to time.	fieldUtils

Method Details

getDisplayFieldName Method getDisplayFieldName(layer){String |null |undefined} Since: ArcGIS Maps SDK for JavaScript 4.15 fieldUtils since 4.11, getDisplayFieldName added at 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 \| null \| undefined	The name of the display field to use for labeling.

getElevationFields Method 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|null|undefined

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 Method getExpressionFields(layer, expressions){Promise<String[]>} Since: ArcGIS Maps SDK for JavaScript 4.15 fieldUtils since 4.11, getExpressionFields added at 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

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

Type	Description
Promise<String []>	Returns an array of field names declared either by the `$feature.fieldName` or `$feature[fieldName]` syntax.

See also

Arcade - expression language

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 Method getFeatureEditFields(layer){String[]}

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

Parameter

layer FeatureLayer|SubtypeGroupLayer

The layer from which to extract editor tracking fields.

Returns

Type	Description
String []	An array of field names used for editor tracking.

getFeatureGeometryFields Method getFeatureGeometryFields(layer){String[]} Since: ArcGIS Maps SDK for JavaScript 4.19 fieldUtils since 4.11, getFeatureGeometryFields added at 4.19.

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

Parameter

layer FeatureLayer|SubtypeGroupLayer

The layer to extract geometry fields from.

Returns

Type	Description
String []	An array of geometry field names.

getLabelingFields Method 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|null|undefined

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.

getRendererFields Method getRendererFields(renderer, fieldsIndex){Promise<String[]>} Since: ArcGIS Maps SDK for JavaScript 4.30 fieldUtils since 4.11, getRendererFields added at 4.30.

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

Parameters

renderer RendererUnion|null|undefined

Layer's renderer to collect field names used in that renderer.

fieldsIndex FieldsIndex

The field index of the layer. It can be used to make case-insensitive lookups for a field by name.

Returns

Type	Description
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);

getTimeFields Method 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|null|undefined

The Feature Layer from which to extract time fields.

Returns

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