HistogramViewModel | API Reference | ArcGIS Maps SDK for JavaScript 4.31

Provides the logic for the Histogram widget.

See also

Constructors

HistogramViewModel Constructor new HistogramViewModel(properties)

Parameter

properties Object

optional

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

Property Overview

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

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Type	Summary	Class
Number	The statistical average of the data in the histogram.	HistogramViewModel
Number	The range of values for the histogram calculated from the bins.	HistogramViewModel
Bin []	An array of objects representing each bin in the histogram.	HistogramViewModel
String	The name of the class.	Accessor
LabelFormatter	A function used to format labels.	HistogramViewModel
Number	The maximum value or bound of the entire histogram.	HistogramViewModel
Number	The minimum value or bound of the entire histogram.	HistogramViewModel
Number	The range of values for the histogram.	HistogramViewModel
String	The current state of the view model.	HistogramViewModel

Property Details

average Property average Number

The statistical average of the data in the histogram. You would typically get this value from the avg property of SummaryStatisticsResult, which is the result of the summaryStatistics function.

When set, this value will render on the histogram with a symbol indicating it is the average.

Examples

// sets result returned from a smart mapping method
// to the histogram
histogramVM.average = response.statistics.avg;

histogramVM.average = 34.5;

binRange Property binRange Numberreadonly

The range of values for the histogram calculated from the bins. This is calculated by subtracting the min value of the first bin from the max value of the last bin.

bins Property bins Bin[]

An array of objects representing each bin in the histogram. This information is typically returned from the histogram function.

Examples

// sets the bins of the histogram from the bins in the histogram() result
histogramVM.bins = histogramResult.bins;

// Creates a histogram with 7 bins.
histogramVM.bins = [
  { minValue: 0, maxValue: 10, count: 4 },
  { minValue: 10.1, maxValue: 20, count: 14 },
  { minValue: 20.1, maxValue: 30, count: 9 },
  { minValue: 30.1, maxValue: 40, count: 34 },
  { minValue: 40.1, maxValue: 50, count: 351 },
  { minValue: 50.1, maxValue: 60, count: 100 },
  { minValue: 60.1, maxValue: 70, count: 1 }
];

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor

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

labelFormatFunction Property labelFormatFunction LabelFormatter

A function used to format labels. Overrides the default label formatter.

Example

// For thumb values, rounds each label to whole numbers.
slider.viewModel.labelFormatFunction = function(value) {
  return value.toFixed(0);
}

max Property max Number

The maximum value or bound of the entire histogram. This should match the maximum bound of the last bin.

Examples

histogramVM.max = 100;

// sets result returned from a smart mapping method
// to the histogram
histogramVM.max = response.statistics.max;

min Property min Number

The minimum value or bound of the entire histogram. This should match the minimum bound of the first bin.

Examples

histogramVM.min = 0;

// sets result returned from a smart mapping method
// to the histogram
histogramVM.min = response.statistics.min;

range Property range Numberreadonly

The range of values for the histogram. This is calculated by subtracting the min from the max.

state Property state Stringreadonly

The current state of the view model.

Possible Values:"ready" |"disabled"

Method Overview

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Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
Boolean	Returns true if a named group of handles exist.	Accessor
	Removes a group of handles owned by the object.	Accessor

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor 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();

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.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 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 Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 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");