var legend = new Legend({
  view: view,
  layerInfos: [{
    layer: featureLayer,
    title: "Legend"
  }]
});

view.ui.add(legend, "bottom-right");

Property Overview

Property Details

activeLayerInfos Collection<ActiveLayerInfo>autocast

Autocasts from Object[]

Collection of ActiveLayerInfo objects used by the legend view to display data in the legend. The legend widget watches this property to hide or display the layer's legend when an ActiveLayerInfo is removed from or added to this collection.

container String|HTMLElement inherited

The ID or node representing the DOM element containing the widget. This property can only be set once.

declaredClass Stringreadonly inherited

Since: ArcGIS API for JavaScript 4.7

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

destroyed Boolean inherited

When true, this property indicates whether the widget has been destroyed.

iconClass String

Since: ArcGIS API for JavaScript 4.7

The widget's default CSS icon class.

id String inherited

The unique ID assigned to the widget when the widget is created. If not set by the developer, it will default to the container ID, or if that is not present then it will be automatically generated.

label String

Since: ArcGIS API for JavaScript 4.7

The widget's default label.

layerInfos Object[]

Specifies a subset of the layers to display in the legend. If this property is not set, all layers in the map will display in the legend. Objects in this array are defined with the properties listed below.

Properties:

title String optional Specifies a title for the layer to display above its symbols and descriptions. If no title is specified the service name is used.

layer Layer A layer to display in the legend.

style Object|String

Since: ArcGIS API for JavaScript 4.7

Indicates the style of the legend. The style determines the legend's layout and behavior. You can either specify a string or an object to indicate the style. The known string values are the same values listed in the table within the type property.

Properties:

type String Specifies the style of the legend. There are two possible values listed in the table below: Value Description classic The legend has a portrait orientation. The user can scroll vertically when many elements are included in the legend's content. card In wide views, the legend has a landscape orientation that allows users to scroll horizontally to view all legend elements. This style can be responsive, making it ideal for mobile web apps. In smaller views, the legend collapses to occupy less space. One element is shown at a time in a card-style layout, which the user can navigate horizontally.

layout String optional Default Value:stack When a card type is specified, you can specify one of the following layout options. Value Description auto This layout is responsive so that in wide views the legend has a side-by-side layout, and a stack layout in smaller (mobile) views. side-by-side The legend has a landscape orientation that allows users to scroll horizontally to view multiple legend cards at a time. stack The legend cards are stacked, which conserves space, but restricts the user to seeing only one card at a time.

Default Value:classic

Examples:

// renders the legend in the card style with a "stack" layout
legend.style = "card";

// renders the legend in the card style with a responsive
// layout that toggles between "stack" and "side-by-side"
legend.style = {
  type: "card",
  layout: "auto"
};

// renders the legend in the classic layout
legend.style = "classic";

view MapView|SceneView

A reference to the MapView or SceneView. Set this to link the widget to a specific view.

viewModel LegendViewModelautocast

The view model for this widget. This is a class that contains all the logic (properties and methods) that controls this widget's behavior. See the LegendViewModel class to access all properties and methods on the widget.

Method Overview

Method Details

classes(classNames){String}inherited

Since: ArcGIS API for JavaScript 4.7

A utility method used for building the value for a widget's class property. This aids in simplifying CSS class setup.

Parameter:

classNames (String|String[]|Object)[] repeatable The class names.

Returns:

Type	Description
String	The computed class name.

See also:

• Guide - Widget development (rendering)

Example:

// .tsx syntax showing how to set CSS classes while rendering the widget

render() {
  const dynamicIconClasses = {
    [CSS.myIcon]: this.showIcon,
    [CSS.greyIcon]: !this.showIcon
  };

  return (
    <div class={classes(CSS.root, CSS.mixin, dynamicIconClasses)} />
  );
}

destroy()inherited

Destroys the widget instance.

emit(type, event){Boolean}inherited

Since: ArcGIS API for JavaScript 4.5

Emits an event on the instance. This method should only be used when creating subclasses of this class.

Parameters:

type String The name of the event.

event Object optional The event payload.

Returns:

Type	Description
Boolean	true if a listener was notified

hasEventListener(type){Boolean}inherited

Indicates whether there is an event listener on the instance that matches the provided event name.

Parameter:

type String The name of the event.

Returns:

Type	Description
Boolean	Returns true if the class supports the input event.

on(type, listener){Object}inherited

Registers an event handler on the instance. Call this method to hook an event with a listener.

Parameters:

type String|String[] A event type, or an array of event types, to listen for.

listener Function The function to call when the event is fired.

Returns:

Type	Description
Object	Returns an event handler with a remove() method that can be called to stop listening for the event(s). Property Type Description remove Function When called, removes the listener from the event.

Example:

view.on("click", function(event){
  // event is the event handle returned after the event fires.
  console.log(event.mapPoint);
});

own(handles)inherited

Widget teardown helper. Any handles added to it will be automatically removed when the widget is destroyed.

Parameter:

handles WatchHandle|WatchHandle[] Handles marked for removal once the widget is destroyed.

postInitialize()inherited

This method is primarily used by developers when implementing custom widgets. Executes after widget is ready for rendering.

render(){Object}inherited

This method is primarily used by developers when implementing custom widgets. It must be implemented by subclasses for rendering.

Returns:

Type	Description
Object	The rendered virtual node.

renderNow()inherited

Renders widget to the DOM immediately.

scheduleRender()inherited

This method is primarily used by developers when implementing custom widgets. Schedules widget rendering. This method is useful for changes affecting the UI.