require(["esri/rest/support/TopFilter"], (TopFilter) => { /* code goes here */ });
import TopFilter from "@arcgis/core/rest/support/TopFilter.js";
esri/rest/support/TopFilter
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 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 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
-
Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
| Name | Type | Summary | Class |
|---|---|---|---|
The name of the class. | Accessor | ||
When one or more field names are provided in this property, the output result will be grouped based on unique values from those fields. | TopFilter | ||
One or more field names used to order the query results. | TopFilter | ||
Defines the number of features to be returned from the top features query. | TopFilter |
Property Details
-
When one or more field names are provided in this property, the output result will be grouped based on unique values from those fields.
-
One or more field names used to order the query results. Specify
ASC(ascending) orDESC(descending) after the field name to control the order. The default order isASC.Exampleconst query = new TopFeaturesQuery({ outFields: ["State, Pop_total, County"], topFilter: new TopFilter({ topCount: 3, groupByFields: ["State"], orderByFields: ["Pop_total DESC"] }) });
-
Defines the number of features to be returned from the top features query.
Exampleconst query = new TopFeaturesQuery({ outFields: ["State, Pop_total, County"], topFilter: new TopFilter({ topCount: 3, groupByFields: ["State"], orderByFields: ["Pop_total DESC"] }) });
Method Overview
| Name | Return Type | Summary | Class |
|---|---|---|---|
Adds one or more handles which are to be tied to the lifecycle of the object. | Accessor | ||
Creates a deep clone of TopFilter object. | TopFilter | ||
Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. | TopFilter | ||
Returns true if a named group of handles exist. | Accessor | ||
Removes a group of handles owned by the object. | Accessor | ||
Converts an instance of this class to its ArcGIS portal JSON representation. | TopFilter |
Method Details
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, addHandles added at 4.25. -
Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.
// Manually manage handles const handle = reactiveUtils.when( () => !view.updating, () => { wkidSelect.disabled = false; }, { once: true } ); this.addHandles(handle); // Destroy the object this.destroy();ParametershandleOrHandles WatchHandle|WatchHandle[]Handles marked for removal once the object is destroyed.
groupKey *optionalKey identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.
-
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
jsonparameter 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.Parameterjson ObjectA 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
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hasHandles
InheritedMethodhasHandles(groupKey){Boolean}Inherited from AccessorSince: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, hasHandles added at 4.25. -
Returns true if a named group of handles exist.
ParametergroupKey *optionalA group key.
ReturnsType Description Boolean Returns trueif a named group of handles exist.Example// Remove a named group of handles if they exist. if (obj.hasHandles("watch-view-updates")) { obj.removeHandles("watch-view-updates"); }
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, removeHandles added at 4.25. -
Removes a group of handles owned by the object.
ParametergroupKey *optionalA group key or an array or collection of group keys to remove.
Exampleobj.removeHandles(); // removes handles from default group obj.removeHandles("handle-group"); obj.removeHandles("other-handle-group");
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toJSON
MethodtoJSON(){Object} -
Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.
ReturnsType Description Object The ArcGIS portal JSON representation of an instance of this class.