UnknownLayer

Class: esri/layers/UnknownLayer
Inheritance: UnknownLayer Layer Accessor
Since: ArcGIS API for JavaScript 4.0

Represents a layer whose type could not be determined. For example, when loading a layer from a URL and the layer type cannot be determined, then it is represented as an instance of this class.

An instance of this class may also be used when loading a WebMap or a WebScene. If the service of one of the layers in the WebMap/WebScene is not available and the layer type cannot be determined, then it is represented as an UnknownLayer. It is important to note that constructing layers from this class is not supported.

See also:

Property Overview

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

The name of the class.

more details
more detailsAccessor
Extent

The full extent of the layer.

more details
more detailsLayer
String

The unique ID assigned to the layer.

more details
more detailsLayer
String

Indicates how the layer should display in the LayerList widget.

more details
more detailsLayer
Boolean

Indicates whether the layer's resources have loaded.

more details
more detailsLayer
Error

The Error object returned if an error occurred while loading.

more details
more detailsLayer
String

Represents the status of a load operation.

more details
more detailsLayer
Object[]

A list of warnings which occurred while loading.

more details
more detailsLayer
Number

The opacity of the layer.

more details
more detailsLayer
String

The title of the layer used to identify it in places such as the Legend and LayerList widgets.

more details
more detailsLayer
String

For UnknownLayer the type is unknown.

more details
more detailsUnknownLayer
Boolean

Indicates if the layer is visible in the View.

more details
more detailsLayer

Property Details

declaredClassStringreadonly inherited

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

The full extent of the layer. By default, this is worldwide. This property may be used to set the extent of the view to match a layer's extent so that its features appear to fill the view. See the sample snippet below.

Example:
// Once the layer loads, set the view's extent to the layer's fullextent
layer.then(function(){
  view.extent = layer.fullExtent;
});

The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded.

Indicates how the layer should display in the LayerList widget. The known values are listed below.

ValueDescription
showThe layer is visible in the table of contents.
hideThe layer is hidden in the table of contents.
hide-childrenIf the layer is a GroupLayer, hide the children layers from the table of contents.
Default Value: show

loadedBooleanreadonly inherited

Indicates whether the layer's resources have loaded. When true, all the properties of the object can be accessed.

Default Value: false

loadErrorErrorreadonly inherited

The Error object returned if an error occurred while loading.

Default Value: null

loadStatusStringreadonly inherited

Represents the status of a load operation.

ValueDescription
not-loadedThe object's resources have not loaded.
loadingThe object's resources are currently loading.
loadedThe object's resources have loaded without errors.
failedThe object's resources failed to load. See loadError for more details.
Default Value: not-loaded

loadWarningsObject[]readonly inherited

A list of warnings which occurred while loading.

The opacity of the layer. This value can range between 1 and 0, where 0 is 100 percent transparent and 1 is completely opaque.

Default Value: 1
Example:
// Makes the layer 50% transparent
layer.opacity = 0.5;

The title of the layer used to identify it in places such as the Legend and LayerList widgets.

typeStringreadonly

For UnknownLayer the type is unknown.

Indicates if the layer is visible in the View. When false, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.

Default Value: true
Example:
// The layer is no longer visible in the view
layer.visible = false;

Method Overview

NameReturn TypeSummaryClass
Promise

An instance of this class is a Promise.

more details
more detailsLayer

Cancels a load() operation if it is already in progress.

more details
more detailsLayer

Emits an event on the instance.

more details
more detailsLayer
Promise<Object>

Fetches custom attribution data for the layer when it becomes available.

more details
more detailsLayer
Boolean

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

more details
more detailsLayer
Boolean

An instance of this class is a Promise.

more details
more detailsLayer
Boolean

An instance of this class is a Promise.

more details
more detailsLayer
Boolean

An instance of this class is a Promise.

more details
more detailsLayer
Promise

Loads the resources referenced by this class.

more details
more detailsLayer
Object

Registers an event handler on the instance.

more details
more detailsLayer
Promise

An instance of this class is a Promise.

more details
more detailsLayer
Promise

An instance of this class is a Promise.

more details
more detailsLayer

Method Details

always(callbackOrErrback){Promise}inherited

An instance of this class is a Promise. Therefore always() may be used to execute a function if the promise is rejected or resolved. The input function will always execute no matter the response. For more information about promises, see the Working with Promises guide page.

Parameter:
callbackOrErrback Function
optional

The function to execute when the promise is rejected or resolved.

Returns:
TypeDescription
PromiseReturns a new promise for the result of callbackOrErrback.
Example:
// Although this example uses MapView, any class instance that is a promise may use always() in the same way
var view = new MapView();
view.always(function(){
  // This function will always execute whether or not the promise is resolved or rejected
});

cancelLoad()inherited

Cancels a load() operation if it is already in progress.

emit(type, event)protectedinherited

Since: ArcGIS API for JavaScript 4.5

Emits an event on the instance. This method should only be used when creating subclasses that inherit from Evented.

Parameters:
type String

The name of the event.

event Object

The event payload.

fetchAttributionData(){Promise<Object>}inherited

Fetches custom attribution data for the layer when it becomes available.

Returns:
TypeDescription
Promise< Object>Resolves to an object containing custom attribution data for the layer.

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.

isFulfilled(){Boolean}inherited

An instance of this class is a Promise. Therefore isFulfilled() may be used to verify if the promise is fulfilled (either resolved or rejected). If it is fulfilled, true will be returned. See the Working with Promises guide page for more information about promises.

Returns:
TypeDescription
BooleanIndicates whether the promise has been fulfilled (either resolved or rejected).

isRejected(){Boolean}inherited

An instance of this class is a Promise. Therefore isRejected() may be used to verify if the promise is rejected. If it is rejected, true will be returned. See the Working with Promises guide page for more information about promises.

Returns:
TypeDescription
BooleanIndicates whether the promise has been rejected.

isResolved(){Boolean}inherited

An instance of this class is a Promise. Therefore isResolved() may be used to verify if the promise is resolved. If it is resolved, true will be returned. See the Working with Promises guide page for more information about promises.

Returns:
TypeDescription
BooleanIndicates whether the promise has been resolved.

Loads the resources referenced by this class. This method automatically executes for a View and all of the resources it references in Map if the view is constructed with a map instance.

This method must be called by the developer when accessing a resource that will not be loaded in a View.

Returns:
TypeDescription
PromiseResolves when the resources have loaded.

on(type, listener){Object}inherited

Registers an event handler on the instance. Call this method to hook an event with a listener. See the Events summary table for a list of listened events.

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);
});

otherwise(errback){Promise}inherited

An instance of this class is a Promise. Use otherwise() to call a function once the promise is rejected.

Parameter:
errback Function
optional

The function to execute when the promise fails.

Returns:
TypeDescription
PromiseReturns a new promise for the result of errback.
Example:
// Although this example uses MapView, any class instance that is a promise may use otherwise() in the same way
var view = new MapView();
view.otherwise(function(error){
  // This function will execute if the promise is rejected due to an error
});

then(callback, errback, progback){Promise}inherited

An instance of this class is a Promise. Therefore then() may be leveraged once an instance of the class is created. This method takes two input parameters: a callback function and an errback function. The callback executes when the promise resolves (when the instance of the class loads). The errback executes if the promise fails. See the Working with Promises guide page for additional details.

Parameters:
callback Function
optional

The function to call when the promise resolves.

errback Function
optional

The function to execute when the promise fails.

progback Function
optional

The function to invoke when the promise emits a progress update.

Returns:
TypeDescription
PromiseReturns a new promise for the result of callback that may be used to chain additional functions.
Example:
// Although this example uses MapView, any class instance that is a promise may use then() in the same way
var view = new MapView();
view.then(function(){
  // This function will execute once the promise is resolved
}, function(error){
  // This function will execute if the promise is rejected due to an error
});

Event Overview

NameTypeSummaryClass
{view: View,layerView: LayerView}

Fires after the layer's LayerView is created and rendered in a view.

more details
more detailsLayer
{view: View,layerView: LayerView}

Fires after the layer's LayerView is destroyed and no longer renders in a view.

more details
more detailsLayer

Event Details

layerview-createinherited

Fires after the layer's LayerView is created and rendered in a view.

Properties:
view View

The view in which the layerView was created.

layerView LayerView

The LayerView rendered in the view representing the layer in layer.

See also:
Example:
// This function will fire each time a layer view is created for this
// particular view.
layer.on("layerview-create", function(event){
  // The LayerView for the layer that emitted this event
  event.layerView;
});

layerview-destroyinherited

Fires after the layer's LayerView is destroyed and no longer renders in a view.

Properties:
view View

The view in which the layerView was destroyed.

layerView LayerView

The destroyed LayerView representing the layer.

API Reference search results

NameTypeModule

There were no match results from your search criteria.