Loads a WebMap from ArcGIS Online or Portal for ArcGIS into a MapView.
To load a WebMap into a MapView, you must reference the ID of the webmap in the portalItem property of this class.
var webmap = new WebMap({
portalItem: { // autocasts as new PortalItem()
id: "e691172598f04ea8881cd2a4adaa45ba"
}
});
Then you must reference the WebMap instance in the map
property of the view.
var view = new MapView({
map: webmap, // The WebMap instance created above
container: "viewDiv"
});
Working with the WebMap is partially supported. This means it relies on capabilities already available in the API. For example, although it is possible to read WebMaps if they contain layer types that are not yet implemented (e.g. KML layers), only layer types supported by the API will display.
In these instances, the layer types that are not yet supported in the API will be created as an UnsupportedLayer. This layer type is used specifically in these instances where the layer may exist in a given WebMap, e.g. KML layers, but may not be currently supported in the version of the API accessing it (e.g. 4.4 does not support KML layers).
An UnknownLayer will be used if future versions of the WebMap contains a new type of layer. The API version may not recognize this layer type, therefore it would come across as an UnknownLayer.
Various sample WebMaps are made available and can be accessed here.
Constructors
new WebMap(properties)
properties Object See the properties for a list of all the properties that may be passed into the constructor. |
// Typical usage
var map = new WebMap({
portalItem: {
id: "e691172598f04ea8881cd2a4adaa45ba"
}
});
Property Overview
Name | Type | Summary | |
---|---|---|---|
Collection | A flat collection of all the layers in the map. more details | more details | |
Object | Object responsible for containing the viewing and editing properties of the WebMap. more details | more details | |
Basemap | Specifies a basemap for the map. more details | more details | |
Object[] | An array of saved geographic extents that allow end users to quickly navigate to a particular area of interest. more details | more details | |
String | The name of the class. more details | more details | |
Ground | Specifies the surface properties for the map. more details | more details | |
InitialViewProperties | The initial view of the WebMap. more details | more details | |
Collection | A collection of operational layers. more details | more details | |
Boolean | Indicates whether the instance has loaded. more details | more details | |
Error | The Error object returned if an error occurred while loading. more details | more details | |
String | Represents the status of a load operation. more details | more details | |
PortalItem | The portal item from which the WebMap is loaded. more details | more details | |
Object | Provides multiple slides. more details | more details | |
Object | The version of the source document from which the WebMap was read. more details | more details | |
Object[] | An array of table objects in the WebMap. more details | more details | |
Object | The widgets object contains widgets that should be exposed to the user. more details | more details |
Property Details
allLayersCollectionreadonly
A flat collection of all the layers in the map. This collection contains basemap layers, operational layers and ground layers. Group Layers and their children layers are also part of this collection. Reference layers in the basemap will always be included at the end of the collection.
Layers should not be added directly to this collection. They must only be added via the layers, basemap or ground properties.
Example:// Find a layer with title "US Counties" var foundLayer = map.allLayers.find(function(layer) { return layer.title === "US Counties"; }); // Create a filtered collection of the non-group layers var nonGroupLayers = map.allLayers.filter(function(layer) { return !foundLayer.layers; }); // Listen for any layer being added or removed in the Map map.allLayers.on("change", function(event) { console.log("Layer added: ", event.added); console.log("Layer removed: ", event.removed); console.log("Layer moved: ", event.moved); });
applicationPropertiesObject
Object responsible for containing the viewing and editing properties of the WebMap.
Specifies a basemap for the map. The basemap is a set of tile layers that give geographic context to the MapView or SceneView and the other operational layers in the map.
This value can be an instance of Basemap or one of the strings listed in the table below.
Value Description streets satellite hybrid topo gray dark-gray oceans national-geographic terrain osm dark-gray-vector gray-vector streets-vector topo-vector streets-night-vector streets-relief-vector streets-navigation-vector Example:// Set the basemap in the constructor var map = new Map({ basemap: "streets" }); // Set the basemap after the map instance is created map.basemap = "topo";
bookmarksObject[]
An array of saved geographic extents that allow end users to quickly navigate to a particular area of interest.
declaredClassStringreadonly
The name of the class. The declared class name is formatted as
esri.folder.className
.Specifies the surface properties for the map. This property is only relevant when adding the map to a 3D SceneView. It renders the terrain or topographical variations in the real world on the map's surface with a collection of ElevationLayer.
This value can be an instance of Ground, or the string
world-elevation
for a default instance of ground using the World Elevation Service.- See also:
Examples:// Use the world elevation service var map = new Map({ basemap: "topo", ground: "world-elevation" });
// Create a map with the world elevation layer overlaid by a custom elevation layer var worldElevation = ElevationLayer({ url: "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer" }); var customElevation = ElevationLayer({ url: "http://my.server.com/arcgis/rest/service/MyElevationService/ImageServer" }); var map = new Map({ basemap: "topo", ground: new Ground({ layers: [ worldElevation, customElevation ] }) });
initialViewPropertiesInitialViewProperties autocast
The initial view of the WebMap. This object contains properties such as viewpoint, spatialReference, that should be applied to the view when the WebMap loads.
layersCollection autocast
A collection of operational layers. This property only contains interactive operational layers, such as FeatureLayers, WebTileLayers and GraphicsLayers that may be queried, assigned different renderers, analyzed, etc. It does not include basemaps.
A layer is a collection of one or more features, or graphics, that represent real-world phenomena. Each feature contains a symbol and geographic data that allows it to be rendered on the map as a graphic with spatial context. Features within the layer may also contain data attributes that provide additional information that may be viewed in popup windows and used for rendering the layer.
Layers may be added in the constructor, with the add() or addMany() methods, or directly to the layers collection using add() or addMany().
A layer may only be added to one parent. Adding the same layer to multiple Maps or GroupLayers is not possible. If you attempt to do so, the layer will automatically be removed from its current parent and placed in the new parent.
var layer = new GraphicsLayer(); // The layer belongs to map1 map1.layers.add(layer); // The layer now belongs to map2 // and implicitly does: map1.layers.remove(layer) map2.layers.add(layer);
Example:// Add layers in the constructor of Map using an array var fl = new FeatureLayer(url); var gl = new GraphicsLayer(); var map = new Map({ layers: [fl, gl] }); // Add layers using add() map.addMany([fl, gl]); // Add layers using layers collection map.layers.addMany([fl, gl]);
loadedBooleanreadonly
Indicates whether the instance has loaded. When
true
, the properties of the object can be accessed. A WebMap is considered loaded when its layers and basemap are created, but not yet loaded.Default Value: falseloadErrorErrorreadonly
The Error object returned if an error occurred while loading.
Default Value: nullloadStatusStringreadonly
Represents the status of a load operation.
Value Description not-loaded The object's resources have not loaded. loading The object's resources are currently loading. loaded The object's resources have loaded without errors. failed The object's resources failed to load. See loadError for more details. Default Value: not-loadedportalItemPortalItem autocast
The portal item from which the WebMap is loaded.
presentationObject
Provides multiple slides. Each slide has a different "title", "extent", "basemap", "layers" etc.
sourceVersionObjectreadonly
Since: ArcGIS API for JavaScript 4.1The version of the source document from which the WebMap was read. The WebMap must be version 2.x to load into an app.
tablesObject[]
An array of table objects in the WebMap.
widgetsObject
The widgets object contains widgets that should be exposed to the user.
Method Overview
Name | Return Type | Summary | |
---|---|---|---|
Adds a layer to the layers collection. more details | more details | ||
Adds a layer or an array of layers to the layers collection. more details | more details | ||
Promise | An instance of this class is a Promise. more details | more details | |
Layer | Returns a layer based on the given layer id. more details | more details | |
Boolean | An instance of this class is a Promise. more details | more details | |
Boolean | An instance of this class is a Promise. more details | more details | |
Boolean | An instance of this class is a Promise. more details | more details | |
Promise | Triggers the loading of the WebMap instance. more details | more details | |
Promise | An instance of this class is a Promise. more details | more details | |
Layer | Removes the specified layer from the layers collection. more details | more details | |
Layer[] | Removes all layers. more details | more details | |
Layer[] | Removes the specified layers. more details | more details | |
Layer | Changes the layer order. more details | more details | |
Promise | An instance of this class is a Promise. more details | more details |
Method Details
add(layers, index)inherited
Adds a layer to the layers collection.
Parameters:layers LayerLayer to be added to the layers collection.
optionalindex NumberA layer can be added at a specified index in the layers collection. If no index is specified or the index specified is greater than the current number of layers, the layer is automatically appended to the list of layers in the layers collection and the index is normalized.
addMany(layers, index)inherited
Adds a layer or an array of layers to the layers collection.
Parameters:layers Layer[]Layer(s) to be added to the layers collection.
optionalindex NumberA layer can be added at a specified index in the layers collection. If no index is specified or the index specified is greater than the current number of layers, the layer is automatically appended to the list of layers in the layers collection and the index is normalized.
always(callbackOrErrback){Promise}
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:optionalcallbackOrErrback FunctionThe function to execute when the promise is rejected or resolved.
Returns:Type Description Promise Returns 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 });
Returns a layer based on the given layer id.
Parameter:layerId StringThe ID assigned to the layer.
Returns:Type Description Layer Returns the requested layer object. isFulfilled(){Boolean}
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:Type Description Boolean Indicates whether the promise has been fulfilled (either resolved or rejected). isRejected(){Boolean}
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:Type Description Boolean Indicates whether the promise has been rejected. isResolved(){Boolean}
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:Type Description Boolean Indicates whether the promise has been resolved. load(){Promise}
Triggers the loading of the WebMap instance.
A WebMap is considered loaded when its operational layers and basemap are fully created. When created with a portalItem,
load()
will first fetch its data to create the content, otherwise it resolves immediately.The MapView automatically calls the
load()
method when a WebMap instance is added to its map property so it can display in the view and load each individual layer. If the WebMap is used outside of a view, for example to preload it, you must callload()
explicitly to interact with its resources.Returns:Type Description Promise Resolves when the WebMap is loaded. - See also:
Example:require([ "esri/WebMap", "dojo/promise/all" ], function( WebMap, all ) { var map = new WebMap({ portalItem: { id: "e691172598f04ea8881cd2a4adaa45ba" } }); map.load() .then(function() { // load the basemap to get its layers created return map.basemap.load(); }) .then(function() { // grab all the layers and load them var allLayers = map.allLayers; var promises = allLayers.map(function(layer) { return layer.load(); }); return all(promises.toArray()); }) .then(function(layers) { // each layer load promise resolves with the layer console.log("all " + layers.length + " layers loaded"); }) .otherwise(function(error) { console.error(error); }); });
otherwise(errback){Promise}
An instance of this class is a Promise. Use
otherwise()
to call a function once the promise is rejected.Parameter:optionalerrback FunctionThe function to execute when the promise fails.
Returns:Type Description Promise Returns 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 });
Removes the specified layer from the layers collection.
Parameter:layer LayerLayer to remove from the layers collection.
Returns:Type Description Layer Returns the layer removed from the layers collection. Removes all layers.
Returns:Type Description Layer[] Returns the layers removed from the layers collection. Removes the specified layers.
Parameter:layers Layer[]Array of layers to remove from the layers collection.
Returns:Type Description Layer[] Returns the layers removed from the layers collection. Changes the layer order. The first layer added is always the base layer, even if its order is changed.
Parameters:layer LayerThe layer to be moved.
index NumberThe index location for placing the layer. The bottom-most layer has an index of
0
.Returns:Type Description Layer Returns the layer that was moved. then(callback, errback, progback){Promise}
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: acallback
function and anerrback
function. Thecallback
executes when the promise resolves (when the instance of the class loads). Theerrback
executes if the promise fails. See the Working with Promises guide page for additional details.Parameters:optionalcallback FunctionThe function to call when the promise resolves.
optionalerrback FunctionThe function to execute when the promise fails.
optionalprogback FunctionThe function to invoke when the promise emits a progress update.
Returns:Type Description Promise Returns 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 });