require(["esri/layers/support/AggregateField"], (AggregateField) => { /* code goes here */ });
import AggregateField from "@arcgis/core/layers/support/AggregateField.js";
esri/layers/support/AggregateField
Defines the aggregate fields used in a layer visualized with FeatureReductionBinning or FeatureReductionCluster. An aggregate field aggregates data from a layer's field using a statistic type such as the average or sum.
featureReduction.fields = [{
name: "SUM_population",
alias: "Total population",
onStatisticField: "population",
statisticType: "sum"
}, {
name: "AVG_age",
alias: "Average age",
onStatisticField: "age",
statisticType: "avg"
}];
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 display name that describes the aggregate field in the Legend, Popup, and other UI elements. | AggregateField | ||
The name of the class. | Accessor | ||
Indicates whether the field was created internally by the JS API's rendering engine for default FeatureReductionCluster visualizations. | AggregateField | ||
The name of the aggregate field. | AggregateField | ||
An object containing an Arcade expression, which evaluates for each child feature represented by the aggregate graphic. | AggregateField | ||
The name of the layer field to summarize with the given statisticType. | AggregateField | ||
Defines the type of statistic used to aggregate data returned from onStatisticField or onStatisticExpression. | AggregateField |
Property Details
-
alias
alias String
-
- Default Value:null
ExampleaggregateField.alias = "Total population";
-
isAutoGenerated
isAutoGenerated Boolean
Since: ArcGIS Maps SDK for JavaScript 4.25AggregateField since 4.24, isAutoGenerated added at 4.25. -
Indicates whether the field was created internally by the JS API's rendering engine for default FeatureReductionCluster visualizations. You should avoid setting or changing this value. If
true
, then all other properties of the AggregateField are read-only.- Default Value:false
-
name
name String
-
The name of the aggregate field. This should describe the layer's field and aggregation method used. For example, if creating a field that contains the total population for a set of features with a population field, then you could name this field
total_population
orpopulation_sum
.This field name must start with a letter, and may only contain alphanumeric characters and underscore.
Example// names the aggregate field that will display the sum of the population // for all points representing cities in the bin aggregateField.name = "SUM_population";
-
onStatisticExpression
onStatisticExpression ExpressionInfo
Since: ArcGIS Maps SDK for JavaScript 4.25AggregateField since 4.24, onStatisticExpression added at 4.25. -
An object containing an Arcade expression, which evaluates for each child feature represented by the aggregate graphic. All results of the expression will be aggregated using the given statisticType. This expression must follow the specification defined by the Arcade Visualization Profile. Expressions must return a string or a number and may access data values from the layer's feature with the
$feature
profile variable.Example// will create an aggregate field for the Population field of the layer. aggregateField.onStatisticExpression = new ExpressionInfo({ title: "Population per square kilometer", returnType: "number", expression: "$feature.population / AreaGeodetic($feature, 'square-kilometers')" });
-
onStatisticField
onStatisticField String
Since: ArcGIS Maps SDK for JavaScript 4.25AggregateField since 4.24, onStatisticField added at 4.25. -
The name of the layer field to summarize with the given statisticType.
Example// will create an aggregate field for the Population field of the layer. aggregateField.onStatisticField = "Population";
-
statisticType
statisticType String
Since: ArcGIS Maps SDK for JavaScript 4.25AggregateField since 4.24, statisticType added at 4.25. -
Defines the type of statistic used to aggregate data returned from onStatisticField or onStatisticExpression.
Possible Values
Value Description avg
The average of values in the aggregate. Only available for fields and expressions that return numbers. count
The total number of features in the aggregate. A field does not need to be specified in this case. max
The maximum of all values in the aggregate. Only available for fields and expressions that return numbers. min
The minimum of all values in the aggregate. Only available for fields and expressions that return numbers. mode
The most common or predominant value in the aggregate. Available for fields and expressions that return numbers or strings. sum
The sum of all values in the aggregate. Only available for fields and expressions that return numbers. Possible Values:"avg" |"count" |"max" |"min" |"mode" |"sum" |"avg_angle"
Example// will calculate the sum of the field specified in onStatisticField for all features in the bin. outStatistic.statisticType = "sum";
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 the AggregateField object. | AggregateField | ||
* | Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. | AggregateField | |
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. | AggregateField |
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.
-
clone
clone(){AggregateField}
-
Creates a deep clone of the AggregateField object.
ReturnsType Description AggregateField A deep clone of the object that invoked this method. Example// Creates a deep clone of the AggregateField object const sumPopulationField = layer.featureReduction.fields.find( field => field.name === "SUM_population" ).clone();
-
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.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.
ReturnsType Description * Returns a new instance of this class.
-
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 true
if 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");
-
toJSON
toJSON(){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.