Add a feature layer

Before starting this tutorial:

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

2. Your system meets the system requirements.

3. You need an IDE for Flutter - we recommend VS Code.

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 a Flutter project

1. Open the project you created by completing the Display a map tutorial.

2. Continue with the following instructions to use a URL to access and display a feature layer in a map.

Create feature layers to display the hosted data

To display three new data layersA data layer is a layer that references geographic data from a file or a service and is used to visualize the data in a map or scene.Learn more (also known as operation layers) on top of the current basemap, you will create FeatureLayers using URIs to reference datasets hosted in ArcGIS OnlineArcGIS Online is a GIS mapping, analytics, data hosting, and content management software as a service (SaaS) product. It includes applications, tools, APIs, and location services for users and developers. It is subscription-based and requires an ArcGIS Online account.Learn more.

1. Open lib\main.dart.

2. In onMapViewReady(), define String variables to hold the URLs of each hosted feature layer. You will add: Trailheads (points), Trails (lines), and Parks and Open Spaces (polygons).

   main.dart

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     void onMapViewReady() {
   
       final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISTopographic);
   
       // Trailheads feature service.
       const trailheadsUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trailheads_Styled/FeatureServer/0';
   
       // Trails feature service.
       const trailsUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trails_Styled/FeatureServer/0';
   
       // Parks feature service.
       const parksUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Parks_and_Open_Space_Styled/FeatureServer/0';
   
     }
   

3. Create feature layers by creating ServiceFeatureTables for each URI.

   main.dart

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       // Trailheads feature service.
       const trailheadsUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trailheads_Styled/FeatureServer/0';
   
       // Trails feature service.
       const trailsUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trails_Styled/FeatureServer/0';
   
       // Parks feature service.
       const parksUri =
           'https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Parks_and_Open_Space_Styled/FeatureServer/0';
   
       // Trailheads feature layer using service feature table.
       final trailheadsLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(trailheadsUri)),
       );
   
       // Trails feature layer using service feature table.
       final trailsLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(trailsUri)),
       );
   
       // Parks feature layer using service feature table.
       final parksLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(parksUri)),
       );
   

4. Add the new feature layers to the map.

   main.dart

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       // Trailheads feature layer using service feature table.
       final trailheadsLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(trailheadsUri)),
       );
   
       // Trails feature layer using service feature table.
       final trailsLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(trailsUri)),
       );
   
       // Parks feature layer using service feature table.
       final parksLayer = FeatureLayer.withFeatureTable(
         ServiceFeatureTable.withUri(Uri.parse(parksUri)),
       );
   
       // Add all the feature layers to the map.
       map.operationalLayers.addAll([trailheadsLayer, trailsLayer, parksLayer]);
   
       // Code from `Display a map` tutorial and remains unchanged.
       _mapViewController.arcGISMap = map;
       _mapViewController.setViewpoint(
         Viewpoint.withLatLongScale(
           latitude: 34.02700,
           longitude: -118.80500,
           scale: 72000,
         ),
       );
   

Run the app

1. Make sure you have an Android emulator, iOS simulator or physical device configured and running.

2. In VS Code, select Run > Run Without Debugging.

You should see point, line, and polygon features (representing trailheads, trails, and parks) draw on the map for an area in the Santa Monica Mountains.

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 project in VS code.

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

Set up authentication

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.

Add authentication code and 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, you will add authentication code and use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

Run the application

Follow these steps to run the application.

1. In VS Code's terminal, run:

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   flutter pub upgrade

2. Run:

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   dart run arcgis_maps install

3. Make sure you have an Android emulator, iOS simulator or physical device configured and running.

4. In VS Code, select Run > Run Without Debugging.

You should see point, line, and polygon features (representing trailheads, trails, and parks) draw on the map for an area in the Santa Monica Mountains.