TrackInfo | References | ArcGIS Maps SDK for JavaScript

import TrackInfo from "@arcgis/core/layers/support/TrackInfo.js";

Inheritance:: TrackInfo→Accessor

Since: ArcGIS Maps SDK for JavaScript 4.32

beta

TrackInfo provides information about how to display and analyze temporal data in a layer. This information includes how to render the latest observations, previous observations, and track lines. It also includes information about how to aggregate data and display popups. TrackInfo is used in the StreamLayer and FeatureLayer classes.

See also

Constructors

Constructor

Parameters

Parameter	Type	Description	Required
properties	`TrackInfoProperties`

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
`enabled`	`boolean`
`fields`	`AggregateField[]`
`latestObservations`	`TrackPartInfo`
`maxDisplayDuration`	`TimeInterval \| null \| undefined`
`maxDisplayObservationsPerTrack`	`number`
`popupEnabled`	`boolean`
`popupTemplate`	`PopupTemplate \| null \| undefined`
`previousObservations`	`TrackPartInfo`
`timeField`	`"timeReceived" \| "startTimeField" \| "endTimeField"`
`trackLines`	`TrackPartInfo`

declaredClass

readonlyinherited Property

Type: string

Inherited from: Accessor

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

enabled

Property

Type: boolean

Indicates whether the track info is enabled.

Default value: true

Example

trackInfo.enabled = false;

fields

autocast Property

Type: AggregateField[]

An array of aggregate fields that summarize layer.fields in all observations of the track. Only visible observations are included in the aggregated data. Observations filtered out because of maxDisplayObservationsPerTrack or maxDisplayDuration are excluded from any aggregate field calculations.

These fields may only be used by the popupTemplate, and by the TrackPartInfo.labelingInfo and TrackPartInfo.renderer of trackLines.

Example

// Based on the fields in the layer, the following track info fields
// could be defined:
trackInfo.fields = [{
  name: "total_observations",
  statisticType: "count"
}, {
  name: "AVG_speed",
  onStatisticField: "speed",
  statisticType: "avg"
}];

latestObservations

autocast Property

Type: TrackPartInfo

Configuration properties for displaying the latest observations.

Example

trackInfo.latestObservations = {
  renderer: {
    type: "simple",
    symbol: {
      type: "simple-marker",
      style: "circle",
      color: "red",
      size: 10
    }
  }
};

maxDisplayDuration

autocast Property

Type: TimeInterval | null | undefined

The maximum age of displayed observations. Observations older than this will not be displayed. Age is calculated by subtracting the time indicated by timeField from the view.timeExtent.end. For StreamLayer, age is calculated by subtracting the time indicated by timeField from the system time. If no duration is specified, or if its value is 0, then displayed observations will not be limited by age.

Example

trackInfo.maxDisplayDuration = { value: 30, unit: "seconds" };

maxDisplayObservationsPerTrack

Property

Type: number

The maximum number of observations to display per track. If the value is 0, no limit will be imposed.

Default value: 0

Example

trackInfo.maxDisplayObservationsPerTrack = 10;

popupEnabled

Property

Type: boolean

Indicates whether to display the popup for the track as defined in the popupTemplate.

Default value: true

Example

trackInfo.popupEnabled = false;

popupTemplate

autocast Property

Type: PopupTemplate | null | undefined

The PopupTemplate to apply to the track. When set, a popupTemplate independent of the layer.popupTemplate is used. This popup can display summary information for each track, 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.

See also

Arcade Feature Reduction Popup Profile

Example

layer.trackInfo = {
  fields: [{
    name: "avg_speed",
    alias: "Average speed",
    onStatisticField: "speed",
    statisticType: "avg"
  }, {
    name: "total_observations",
    statisticType: "count"
  }],
  popupTemplate: {
    content: [{
      type: "text",
      text: "This track contains <b>{total_observations}</b> features."
    }, {
      type: "text",
      text: "The average speed in this track is <b>{avg_speed}</b>."
    }],
    fieldInfos: [{
      fieldName: "avg_speed",
      format: {
        digitSeparator: true,
        places: 1
      }
    }]
  }
};

previousObservations

autocast Property

Type: TrackPartInfo

Configuration properties for displaying previous observations.

Example

trackInfo.previousObservations = {
  renderer: {
    type: "simple",
    symbol: {
      type: "simple-marker",
      style: "circle",
      color: "blue",
      size: 10
    }
  }
};

timeField

Property

Type: "timeReceived" | "startTimeField" | "endTimeField"

Indicates which field from the layer's TimeInfo will be used to calculate observation ages for maxDisplayDuration. The timeReceived option is the system time when the client received the observation, and is only valid for StreamLayer.

Default value: "startTimeField"

Example

trackInfo.timeField = "timeReceived";

trackLines

autocast Property

Type: TrackPartInfo

Configuration properties for displaying track lines.

Example

trackInfo.trackLines = {
  renderer: {
    type: "simple",
    symbol: {
      type: "simple-line",
      color: "green",
      width: 2
    }
  }
};

Methods

Method	Signature	Class
`fromJSON` inherited static	`fromJSON(json: any): any`	JSONSupportMixin
`clone` inherited	`clone(): this`	ClonableMixin
`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

inherited Method

Signature: clone (): this

Inherited from: ClonableMixin

Creates a deep clone of this object. Any properties that store values by reference will be assigned copies of the referenced values on the cloned instance.

Returns: this
A deep clone of the class instance that invoked this method.

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.