Add a feature layer from a portal item

Before starting this tutorial:

1. You need an ArcGIS Location Platform or ArcGIS Online account.

2. Your system meets the system requirements.

Option 1: Develop the code

To start the tutorial, complete the Display a map tutorial. This creates a map to display the Santa Monica Mountains in California using the topographic basemap from the ArcGIS Basemap Styles serviceThe ArcGIS Basemap Styles service, also referred to as the Basemap Styles service, is a location service that provides basemap styles and data for the world. It returns styles as Mapbox styles and web maps, and data as vector tiles and/or map tiles. It supports all of the styles in the ArcGIS Basemap style and Open Basemap style family. An ArcGIS Location Platform or ArcGIS Online account is required to use the service.Learn more.

Open an Xcode project

1. Open the .xcodeproj project you created by completing the Display a map tutorial.
2. Continue with the following instructions to use an ArcGIS portal item to access and display a feature layer in a map.

Add a feature layer to the map

1. Open the ContentView.swift file and update the map object. Create a PortalItem object referencing the feature layer by passing in the portal and item ID.

   More info

   Each portal item has a unique Item.ID, identified from its URL on ArcGIS Online.

   In your browser, go to the Trailheads Styled layer on ArcGIS Online and find the item ID at the end of the URL. It should be 2e4b3df6ba4b44969a3bc9827de746b3.

   The feature layer referenced with this portal item contains trailheads in and around the Santa Monica Mountains.

   ContentView.swift

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       @State private var map = {
           // Creates a map with the topographic basemap style.
           let map = Map(basemapStyle: .arcGISTopographic)
           // Sets the initial viewpoint to Malibu, California.
           map.initialViewpoint = Viewpoint(latitude: 34.027, longitude: -118.805, scale: 72_000)
   
           // Creates an anonymous portal item pointing to https://www.arcgis.com with an item ID.
           let portalItem = PortalItem(
               portal: .arcGISOnline(connection: .anonymous),
               id: Item.ID("2e4b3df6ba4b44969a3bc9827de746b3")!
           )
   
           return map
       }()
   

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2. Create a FeatureLayer object from the portal item and a layer ID. The layer ID uniquely identifies one of the layers from the portal item. Add the layer to the map's operational layers.

   More info

   A layer ID is required because a portal item may have more than one layer. For instance, when a feature service has 3 layers - trailheads (points), trails (polylines) and trail areas (polygons), the corresponding portal item would contain all three layers.

   ContentView.swift

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       @State private var map = {
           // Creates a map with the topographic basemap style.
           let map = Map(basemapStyle: .arcGISTopographic)
           // Sets the initial viewpoint to Malibu, California.
           map.initialViewpoint = Viewpoint(latitude: 34.027, longitude: -118.805, scale: 72_000)
   
           // Creates an anonymous portal item pointing to https://www.arcgis.com with an item ID.
           let portalItem = PortalItem(
               portal: .arcGISOnline(connection: .anonymous),
               id: Item.ID("2e4b3df6ba4b44969a3bc9827de746b3")!
           )
   
           // Creates a feature layer from the portal item and a layer ID.
           let layer = FeatureLayer(featureServiceItem: portalItem, layerID: 0)
           // Adds the layer to the map's operational layers.
           map.addOperationalLayer(layer)
   
           return map
       }()
   

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Run the solution

Press Command + R to run the app.

You should see a map of trail heads in the Santa Monica mountains. Tap, drag, and zoom on the map view to explore the map.

Option 2: Download the solution

1. Click the Download solution link under Solution and unzip the file to a location on your machine.

2. Open the .xcodeproj file in Xcode.

Since the downloaded solution does not contain authentication credentials, you must first set up authentication to create credentials, and then add the developer credentials to the solution.

Set developer credentials in the solution

To access the secure ArcGIS location servicesArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services.Learn more used in this tutorial, you must implement API key authenticationAPI key authentication is a type of authentication that uses an API key to authenticate requests to ArcGIS services and secure portal items.Learn more or user authenticationUser authentication is a type of authentication that allows users with an ArcGIS account to sign into an application and allow it to access ArcGIS content, services, and resources on their behalf. The typical authorization protocol used is OAuth2.0.Learn more using an ArcGIS Location PlatformAn ArcGIS Location Platform account, formerly known as an ArcGIS Developer account, is an identity associated with an ArcGIS Location Platform subscription.Learn more or an ArcGIS OnlineAn ArcGIS Online account, also known as an ArcGIS Organization account, is an identity associated with an ArcGIS Online subscription. It can be used to access ArcGIS tools and develop applications with ArcGIS location services for an organization.Learn more account.

To complete this tutorial, click on the tab in the switcher below for your authentication type of choice, either API key authentication or User authentication.

Set developer credentials

To allow your app users to access ArcGIS location servicesArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services.Learn more, use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

Run the solution

Press Command + R to run the app.

You should see a map of trail heads in the Santa Monica mountains. Tap, drag, and zoom on the map view to explore the map.