uniqueValues

import uniqueValues from "@arcgis/core/smartMapping/statistics/uniqueValues.js";

Since: ArcGIS Maps SDK for JavaScript 4.4

A function that queries for unique values from a field in a Layer.

Known Limitations

SceneLayers must have the supportsRenderer and supportsLayerQuery capabilities enabled unless a predefined statistics object is provided to the statistics parameter of the method. To check a SceneLayer's capabilities, use the SceneLayer.getFieldUsageInfo() method. You cannot generate unique values using SQL expressions for client-side FeatureLayers in a SceneView.

Functions

Name	Return Type	Object
`uniqueValues`	`Promise<UniqueValuesResult>`

Function

Returns an object containing an array of unique values queried from a given field (or values returned from an expression) in a Layer along with the total count of features that belong to the given category.

Signature: uniqueValues (parameters: UniqueValuesParameters): Promise<UniqueValuesResult>

Parameters

Parameter	Type	Description	Required
parameters	`UniqueValuesParameters`	The function parameters.

Returns: Promise<UniqueValuesResult>
Returns a promise that resolves to UniqueValuesResult.

Example

let layer = new FeatureLayer({
  portalItem: { id: "5ce5374a461e45bab714b43ffedf151d" }
});

uniqueValues({
  layer: layer,
  field: "Candidate"
}).then(function(response){
  // prints each unique value and the count of features containing that value
  let infos = response.uniqueValueInfos;
  infos.forEach(function(info){
    console.log("CANDIDATE: ", info.value, " # OF CAMPAIGN STOPS: ", info.count);
  });
});