require(["esri/widgets/LayerList"], function(LayerList) { /* code goes here */ });
Class: esri/widgets/LayerList
Inheritance: LayerList Widget Accessor
Since: ArcGIS API for JavaScript 4.2

The LayerList widget provides a way to display a list of layers, and switching on/off their visibility.

For information about gaining full control of widget styles, see the Styling topic.
See also:
Example:
var layerList = new LayerList({
  view: view
});
// Adds widget below other elements in the top left corner of the view
view.ui.add(layerList, {
  position: "top-left"
});

Constructors

new LayerList(properties)
Parameter:
properties Object
optional

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

Example:
// typical usage
var layerlist = new LayerList({
  view: view
});

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.
NameTypeSummaryClass
String | HTMLElement

The ID or node representing the DOM element containing the widget.

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more detailsWidget
String

The name of the class.

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more detailsAccessor
Boolean

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

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more detailsWidget
String

The widget's default CSS icon class.

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more detailsLayerList
String

The unique ID assigned to the widget when the widget is created.

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more detailsWidget
String

The widget's default label.

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more detailsLayerList
ListItemCreatedHandler

Specifies a function that accesses each ListItem.

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more detailsLayerList
Collection<ListItem>

A collection of ListItems representing operational layers.

more details
more detailsLayerList
Boolean

Option for enabling status indicators, which indicate whether or not each layer is loading resources.

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more detailsLayerList
MapView | SceneView

A reference to the MapView or SceneView.

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more detailsLayerList
LayerListViewModel

The view model for this widget.

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more detailsLayerList

Property Details

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

declaredClassStringreadonly inherited
Since: ArcGIS API for JavaScript 4.7

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

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

iconClassStringreadonly
Since: ArcGIS API for JavaScript 4.7

The widget's default CSS icon class.

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.

labelStringreadonly
Since: ArcGIS API for JavaScript 4.7

The widget's default label.

listItemCreatedFunctionListItemCreatedHandler
Since: ArcGIS API for JavaScript 4.4

Specifies a function that accesses each ListItem. Each list item can be modified according to its modifiable properties. Actions can be added to list items using the actionsSections property of the ListItem.

See also:
Example:
var layerList = new LayerList({
  view: view,
  // executes for each ListItem in the LayerList
  listItemCreatedFunction: function (event) {

    // The event object contains properties of the
    // layer in the LayerList widget.
    var item = event.item;

    if (item.title === "US Demographics") {
      // open the list item in the LayerList
      item.open = true;
      // change the title to something more descriptive
      item.title = "Population by county";
      // set an action for zooming to the full extent of the layer
      item.actionsSections = [[{
        title: "Go to full extent",
        className: "esri-icon-zoom-out-fixed",
        id: "full-extent"
      }]];
    }
  }
});
operationalItemsCollection<ListItem>

A collection of ListItems representing operational layers.

statusIndicatorsVisibleBoolean
Since: ArcGIS API for JavaScript 4.5

Option for enabling status indicators, which indicate whether or not each layer is loading resources.

Default Value:true
Example:
// disable status indicators for all layers listed in LayerList
layerList.statusIndicatorsVisible = false;

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

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 LayerListViewModel class to access all properties and methods on the widget.

Method Overview

NameReturn TypeSummaryClass
String

A utility method used for building the value for a widget's class property.

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more detailsWidget

Destroys the widget instance.

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more detailsWidget

Emits an event on the instance.

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more detailsWidget
Boolean

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

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more detailsWidget
Object

Registers an event handler on the instance.

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more detailsWidget

Widget teardown helper.

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more detailsWidget

This method is primarily used by developers when implementing custom widgets.

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more detailsWidget
Object

This method is primarily used by developers when implementing custom widgets.

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more detailsWidget

Renders widget to the DOM immediately.

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more detailsWidget

This method is primarily used by developers when implementing custom widgets.

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more detailsWidget

Triggers the trigger-action event and executes the given action or action toggle.

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more detailsLayerList

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.

Prior to version 4.7, there were various approaches towards setting CSS classes. These were dependant upon variables, such as whether the classes were:

  • a single static class,
  • multiple static classes, or
  • dynamic classes.

This helper method takes all of these approaches into account and simplifies it to use one single pattern to accommodate these multiple approaches.

Parameter:
classNames Array<(String|String[]|Object)>
repeatable

The class names.

Returns:
TypeDescription
StringThe computed class name.
See also:
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)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

The event payload.

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:
TypeDescription
BooleanReturns 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

The name of event to listen for.

listener Function

The function to call when the event is fired.

Returns:
TypeDescription
ObjectReturns an event handler with a remove() method that can be called to stop listening for the event.
PropertyTypeDescription
removeFunctionWhen called, removes the listener from the event.
See also:
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 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:
TypeDescription
ObjectThe 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.

triggerAction(action, item)

Triggers the trigger-action event and executes the given action or action toggle.

Parameters:

The action to execute.

An item associated with the action.

Type Definitions

ListItemCreatedHandler(event)

Function definition for the listItemCreatedFunction property. See the example snippet in the listItemCreatedFunction documentation for more details.

Parameters:
event Object

An object containing a list item created by the LayerList.

Specification:

A list item created by the LayerList. You can modify the properties of this item to customize the text, actions, panel content, and visibility of the list item. See the documentation for the listItemCreatedFunction for more details.

Event Overview

NameTypeSummaryClass
{action: ActionButton,ActionToggle,item: ListItem}

Fires after the user clicks on an action or action toggle inside the LayerList widget.

more details
more detailsLayerList

Event Details

trigger-action

Fires after the user clicks on an action or action toggle inside the LayerList widget. This event may be used to define a custom function to execute when particular actions are clicked.

Properties:

The action clicked by the user.

An item associated with the action.

API Reference search results

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