FlowRenderer

const renderer = new FlowRenderer({
  density: 1, // visualization will have the maximum amount of streamlines
  color: [50, 120, 240], // blue
  flowSpeed: 10,
  trailWidth: "2px"
});

Property Overview

Property Details

authoringInfo AuthoringInfoautocast

Contains metadata about renderers generated from the flowRendererCreator.createRenderer() method, including information for setting UI elements such as sliders and themes. This allows the authoring clients to save specific overridable settings so user selections can be remembered the next time they are accessed via the UI.

color Color

The color of the animated streamlines.

Default Value:[255, 255, 255, 1]

declaredClass Stringreadonly inherited

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

density Number

The density of the streamlines. This will determine how many lines appear in the visualization. Accepted values are between 0 and 1. A value of 0 means no lines will be rendered. A value of 1 will render the maximum number of lines.

density = 0.1	density = 0.5	density = 1

Default Value:0.8

flowRepresentation String

Defines the flow direction of the data. This can be modified to display meteorological (the direction it is flowing from) or climatological data (the direction it is flowing to).

Value	Description	Example
flow-from	Flow from angle.
flow-to	Flow to angle.

Possible Values:"flow-from"|"flow-to"

Default Value:"flow-from"

flowSpeed Number

The speed of the animated streamlines, relative to the simulation time. This serves as a multiple of the magnitude from the raster layer. For instance, if the magnitude is 2ms, and the flowSpeed is 10, then the actual speed of the streamline will be 20 pts/s. A speed of 0 will result in no animation.

Default Value:10

legendOptions Object

An object providing options for displaying the renderer in the Legend.

Property

title String optional Describes the variable driving the visualization. This is displayed as the title of the corresponding renderer in the Legend.

Example

renderer.legendOptions = {
  title: "Wind speed"
};

maxPathLength Numberautocast

Autocasts from Number|String

The maximum path length streamlines will travel in points. Only a portion of the streamline will be visible at a time depending on the magnitude or UV coming from the raster layer and the defined trailLength. During the course of the animation, the visible streamline will travel to reach the path length defined here, then will restart. This value may be autocast with a string expressing size in points or pixels (e.g. 100px).

Default Value:200

Examples

// width in points
flowRenderer.maxPathLength = 100;

// width in pixels
flowRenderer.maxPathLength = "200px";

// width in points
flowRenderer.maxPathLength = "100pt";

trailCap String

Since: ArcGIS Maps SDK for JavaScript 4.24

The front cap of the streamline. A round cap will only be applied if trailWidth is greater than 4px or 3pt.

Possible Values:"butt"|"round"

Default Value:"butt"

trailLength Number

The approximate visible length of the streamline in points. The streamlines will appear shorter when the trailLength is a smaller number, since they will start to fade before they reach the full maxPathLength.

trailLength = 20	trailLength = 100	trailLength = 250

Default Value:100

trailWidth Numberautocast

Autocasts from Number|String

The width of the streamline trail in points. This value may be autocast with a string expressing size in points or pixels (e.g. 3px).

Default Value:1.5

Examples

// width in points
flowRenderer.trailWidth = 4;

// width in pixels
flowRenderer.trailWidth = "2px";

// width in points
flowRenderer.trailWidth = "4pt";

type Stringreadonly

The type of Renderer.

For FlowRenderer the type is always "flow".

visualVariables VisualVariable[]autocast

Autocasts from Object[]

An array of VisualVariable objects. Each object must indicate the type of visual variable to apply (e.g. ColorVisualVariable), the numeric field from which to drive the visualization, and the visual values to map to the data. The following list identifies each visual variable type that is supported with the FlowRenderer and provides a link to the specification table of each: ColorVisualVariable, OpacityVisualVariable, and SizeVisualVariable. SizeVisualVariable will update the trailWidth property.

When setting fields for the visual variables set on the FlowRenderer, use the Magnitude field. Magnitude will return pixel values from the first band. If the data represents u (zonal) and v (meridional) speed components, values are automatically converted to Magnitude and Direction.

See also

• Styles and data visualization

Example

const renderer = new FlowRenderer({
   visualVariables: [{
      type: "color",
      field: "Magnitude",
      stops: [
        { value: 3, color: "#0080FF" },
        { value: 15, color: "#00FF00" }
      ]
    }, {
      type: "opacity",
      field: "Magnitude",
      stops: [
        { value: 1, opacity: 0.5 },
        { value: 8, opacity: 1 }
      ]
   }]
});

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(){FlowRenderer}

Creates a deep clone of the renderer.

Returns

Type	Description
FlowRenderer

Example

// Creates a deep clone of the first layer's renderer
let renderer = view.map.layers.getItemAt(0).renderer.clone();

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.