TopFilter | References | ArcGIS Maps SDK for JavaScript

import TopFilter from "@arcgis/core/rest/support/TopFilter.js";

const TopFilter = await $arcgis.import("@arcgis/core/rest/support/TopFilter.js");

Inheritance: TopFilter→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.20

This class defines the top filter parameters for executing top features queries for features from a FeatureLayer. This parameter must be set on the TopFeaturesQuery.topFilter object when calling any of top query methods on a FeatureLayer. It is used to set the groupByFields, orderByFields, and count criteria used the top features query. For example, you can use FeatureLayer's FeatureLayer.queryTopFeatures() method to query the most populous three counties in each state of the United States.

// query the top three most populous counties from each state.
// Results will be ordered based the population of each county in descending order
// top query will run against all features available in the service
const query = new TopFeaturesQuery({
  outFields: ["State, Pop_total, County"],
  topFilter: new TopFilter({
    topCount: 3,
    groupByFields: ["State"],
    orderByFields: ["Pop_total DESC"]
  })
});
featureLayer.queryTopFeatures(query)
  .then(function(response){
     // returns a feature set with features containing the most populous
     // three counties in each state ordered by the number of population.
     // The following attributes are returned as well: State, Pop_total, County
   });

See also

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	TopFilterProperties

See the properties table for a list of all the properties that may be passed into the constructor.

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.

Property	Type	Class
declaredClass readonly inherited	string	Accessor
groupByFields	string[] \| null \| undefined
orderByFields	string[] \| null \| undefined
topCount	number \| null \| undefined

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

The name of the class. The declared class name is formatted as esri.folder.className.

groupByFields

Property

Type: string[] | null | undefined

When one or more field names are provided in this property, the output result will be grouped based on unique values from those fields.

orderByFields

Property

Type: string[] | null | undefined

One or more field names used to order the query results. Specify ASC (ascending) or DESC (descending) after the field name to control the order. The default order is ASC.

Example

const query = new TopFeaturesQuery({
  outFields: ["State, Pop_total, County"],
  topFilter: new TopFilter({
    topCount: 3,
    groupByFields: ["State"],
    orderByFields: ["Pop_total DESC"]
  })
});

topCount

Property

Type: number | null | undefined

Defines the number of features to be returned from the top features query.

Example

const query = new TopFeaturesQuery({
  outFields: ["State, Pop_total, County"],
  topFilter: new TopFilter({
    topCount: 3,
    groupByFields: ["State"],
    orderByFields: ["Pop_total DESC"]
  })
});

Methods

Method	Signature	Class
fromJSON inherited static	fromJSON(json: any): any	JSONSupportMixin
clone	clone(): TopFilter
toJSON inherited	toJSON(): any	JSONSupportMixin

fromJSON

inheritedstatic Method

Signature: fromJSON (json: any): any

Inherited from: JSONSupportMixin

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.

Parameters

Parameter	Type	Description	Required
json	any	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: any
Returns a new instance of this class.

clone

Method

Signature: clone (): TopFilter

Creates a deep clone of TopFilter object.

Returns: TopFilter
A new instance of a TopFilter object equal to the object used to call .clone().

toJSON

inherited Method

Signature: toJSON (): any

Inherited from: JSONSupportMixin

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns: any
The ArcGIS portal JSON representation of an instance of this class.