FeatureReductionBinning

This class configures binning as a means of reducing and summarizing point features in a FeatureLayer, CSVLayer, GeoJSONLayer, WFSLayer, or OGCFeatureLayer. This feature reduction method spatially groups points into bins in geographic space based on predefined geohashes.

Display all points	Points aggregated to bins

Binning only applies to layers with Point geometries in a MapView. It currently does not apply to layers with polyline and polygon geometries.

Known Limitations

• Not supported in 3D SceneView.
• Not supported in MapImageLayer.
• Only supported for layers with a point geometry type.
• Layer views with an applied FeatureEffect cannot be binned.

See also

• Sample - Binning - basic configuration

• Sample - Binning - Filter by category

• Sample - Binning with aggregate fields

• Sample - Summarize binned data using Arcade

• CSVLayer.featureReduction
• FeatureLayer.featureReduction
• GeoJSONLayer.featureReduction
• OGCFeatureLayer.featureReduction

Example

layer.featureReduction = {
  type: "binning",
  fields: [{
    name: "aggregateCount",
    statisticType: "count"
  }]
  renderer: {
    type: "simple",  // autocasts as new SimpleRenderer()
    symbol: {
      type: "simple-fill",  // autocasts as new SimpleFillSymbol()
      outline: {  // autocasts as new SimpleLineSymbol()
        width: 0.5,
        color: "white"
      }
    },
    visualVariables: [{
      type: "color",
      field: "aggregateCount",
      stops: [
        { value: 1, color: "white" },
        { value: 1000, color: "blue" }
      ]
    }]
  },
  popupTemplate: {
    content: "This bin contains <b>{aggregateCount}</b> features.",
    fieldInfos: [{
      fieldName: "aggregateCount",
      format: {
        digitSeparator: true,
        places: 0
      }
    }]
  }
};

Constructors

new FeatureReductionBinning(properties)

Parameter

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

Property Overview

Property Details

declaredClass Stringreadonly inherited

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

fields AggregateField[]autocast

Autocasts from Object[]

An array of aggregate fields that summarize layer fields from features contained within each bin. These fields may be used by the popupTemplate, labelingInfo, and renderer.

Example

featureReduction.fields = [{
  name: "aggregateCount",
  statisticType: "count"
}, {
  name: "SUM_population",
  onStatisticField: "population",
  statisticType: "sum"
}, {
  name: "AVG_age",
  onStatisticField: "age",
  statisticType: "avg"
}, {
  name: "AVG_population_density",
  alias: "Average population density",
  onStatisticExpression: {
    expression: "$feature.population / AreaGeodetic($feature, 'square-miles')",
    title: "population density",
    returnType: "number"
  },
  statisticType: "avg"
}];

fixedBinLevel Number

The fixed geohash level used to create bins. Currently, bin sizes do not dynamically change as the user zooms in and out of the map. Larger numbers will create smaller bins. Levels range from 1 - 9. The following table suggests which bin level to use depending on the approximate view scale.

fixedBinLevel	view.scale
1	> 120,000,000
2	~88,000,000
3	~14,000,000
4	~3,000,000
5	~500,000
6	~84,000
7	~10,000
8	~3,000
9	~400

Default Value:3

Example

featureReduction.fixedBinLevel = 4;

labelingInfo LabelClass[]autocast

Autocasts from Object[]

Defines labels for bins as an array of LabelClass. When set, labels independent of the layer.labelingInfo are used to convey information about each bin. This can include the count of all features in the bin, the average, or sum of a numeric attribute.

Any aggregate field defined in fields can be referenced in the label.

Multiple Label classes with different where clauses can be used to define several labels with varying styles on the same feature. Likewise, multiple label classes may be used to label different types of bins (e.g. blue labels for bins with few features and red labels for bins with many features).

Example

// Displays the count inside the bin
layer.featureReduction = {
  type: "binning",
  fields: [{
    name: "aggregateCount",
    statisticType: "count"
  }],
  labelingInfo: [{
    labelExpressionInfo: {
      expression: "$feature.aggregateCount"
    },
    symbol: {
      type: "text",
      color: "white",
      font: {
        size: "12px"
      },
      haloSize: 1,
      haloColor: "black"
    }
  }]
};

labelsVisible Boolean

Indicates whether to display labels for the bins. If true, labels will appear as defined in the labelingInfo property.

Default Value:true

Example

// Turns off bin labels, but preserves labelingInfo
const featureReduction = layer.featureReduction.clone();
featureReduction.labelsVisible = false;
layer.featureReduction = featureReduction;

maxScale Number

Since: ArcGIS Maps SDK for JavaScript 4.26

Defines the maximum view scale at which binning is enabled. If the user zooms in beyond the scale specified here, binning will be disabled and only individual features will be displayed in the view. Once the user zooms out past this scale, binning will be re-enabled. A value of 0 means binning is always enabled, and therefore binning will be visible at all view scales.

Default Value:0

Example

// binning is disabled when the user zooms
// in beyond a 1:50,000 view scale
layer.featureReduction = {
  type: "binning",
  maxScale: 50000
};

popupEnabled Boolean

Indicates whether to display a popup when a user clicks or touches a bin. If false, the popup as defined in the popupTemplate will be persisted, but won't be displayed on click/tap.

Default Value:true

Example

// Turns off popups, but preserves popupTemplate
const featureReduction = layer.featureReduction.clone();
featureReduction.popupEnabled = false;
layer.featureReduction = featureReduction;

popupTemplate PopupTemplateautocast

The PopupTemplate to apply to bins. When set, a popupTemplate independent of the layer.popupTemplate is used. This popup can display summary information for each bin, such as feature count or any other field defined in fields.

The PopupTemplate may contain one or more Arcade expressions following the specification defined by the Arcade Feature Reduction Popup Profile. Expressions must return a string or a number and may access data values from the bin and its aggregated features with the $feature and $aggregatedFeatures profile variables.

See also

• Arcade Feature Reduction Popup Profile

Examples

// enables binning on the layer with a
// popup describing the number of features represented by each bin
layer.featureReduction = {
  type: "binning",
  fields: [{
    name: "aggregateCount",
    statisticType: "count"
  }],
  popupTemplate: {
    content: "This bin contains <b>{aggregateCount}</b> features."
    fieldInfos: [{
      fieldName: "aggregateCount",
      format: {
        digitSeparator: true,
        places: 0
      }
    }]
  }
};

// enables binning on the layer with a
// popup describing the average value of
// the temperature field
layer.featureReduction = {
  type: "binning",
  fields: [{
    name: "avg_temperature",
    alias: "Average temperature",
    onStatisticField: "temperature",
    statisticType: "avg"
  }, {
    name: "aggregateCount",
    statisticType: "count"
  }],
  popupTemplate: {
    content: [{
      type: "text",
      text: "This bin contains <b>{aggregateCount}</b> features."
    }, {
      type: "text",
      text: "The average temperature in this bin is <b>{avg_temperature}° F</b>."
    }],
    fieldInfos: [{
      fieldName: "aggregateCount",
      format: {
        digitSeparator: true,
        places: 0
      }
    }, {
      fieldName: "avg_temperature",
      format: {
        places: 1
      }
    }]
  }
};

// Displays an ordered list of the top 5 categories
// of features contained within the bin
layer.popupTemplate = {
  title: "Power plant summary",
  content: [{
   type: "expression",
   // lists the top 5 most common fuel types in the bin
   expressionInfo: {
     expression: `
       Expects($aggregatedFeatures, "fuel1")

       var statsFS = GroupBy($aggregatedFeatures,
         [
           { name: 'Type', expression: 'fuel1'},
         ],
         [
           { name: 'num_features', expression: '1', statistic: 'COUNT' }
         ]
       );
       var ordered = Top(OrderBy(statsFs, 'num_features DESC'), 5);

       // create an HTML ordered list as a string and return in a rich text element
       var list = "<ol>";

       for (var group in ordered){
         list += \`<li>\${group.Type} (\${Text(group.num_features, "#,###")})</li>\`
       }
       list += "</ol>";

       return {
         type: "text",
         text: list
       }
     `,
     title: "List of fuel types"
   }
 }]
};

renderer Rendererautocast

The renderer used to style the bins. Depending on the renderer type, features may be visualized with the same symbol or with varying symbols based on the values of the provided fields. Since bins are defined geometrically as polygons, only renderer and symbol types suited for polygon geometries are supported (e.g. HeatmapRenderer is not supported).

Any aggregate field defined in fields may be used by the renderer. Typically, binning visualizations use a field for aggregate count in a color visual variable to visualize the total count of points within each bin.

See also

• Sample - Binning - basic configuration

Example

featureReduction.renderer = {
  type: "simple",  // autocasts as new SimpleRenderer()
  symbol: {
    type: "simple-fill",  // autocasts as new SimpleFillSymbol()
    outline: {  // autocasts as new SimpleLineSymbol()
      width: 0.5,
      color: "white"
    }
  },
  visualVariables: [{
    type: "color",
    field: "aggregateCount",
    stops: [
      { value: 1, color: "white" },
      { value: 1000, color: "blue" }
    ]
  }]
};

type String

The feature reduction type.

For FeatureReductionBinning the type is always "binning".

Example

// enables binning on the layer
layer.featureReduction = {
  type: "binning"
};

Method Overview

Method Details

addHandles(handleOrHandles, groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 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();

Parameters

handleOrHandles WatchHandle|WatchHandle[] Handles marked for removal once the object is destroyed.

groupKey * optional Key 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(){FeatureReductionBinning}

Creates a deep clone of the FeatureReductionBinning object.

Returns

Type	Description
FeatureReductionBinning	A deep clone of the object that invoked this method.

Example

// Creates a deep clone of the feature reduction object
const fr = layer.featureReduction.clone();
fr.fixedBinSize = 5;
layer.featureReduction = fr;

fromJSON(json){*}static

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.

Parameter

json Object 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

Type	Description
*	Returns a new instance of this class.

hasHandles(groupKey){Boolean}inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Returns true if a named group of handles exist.

Parameter

groupKey * optional A group key.

Returns

Type	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");
}

removeHandles(groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Removes a group of handles owned by the object.

Parameter

groupKey * optional A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

toJSON(){Object}

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

Returns

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.