Add a feature layer

Learn how to use a URL to access and display a feature layer in a map.

A map contains layers of geographic data. A map contains a basemap layer and, optionally, one or more data layers. This tutorial shows you how to access and display a feature layer in a map. You access feature layers with an item ID or URL. You will use URLs to access the Trailheads, Trails, and Parks and Open Spaces feature layers and display them in a map.

Steps

Add a layer to the map

1. In the project navigator, open the ViewController.swift file. Update the setupMap() method to create an AGSServiceFeatureTable to access the trail heads data and an AGSFeatureLayer to view it. Add the layer to the map's operational layers.

   More info

   • An AGSServiceFeatureTable is effectively an in-memory database of the features from a service URL.

   • An AGSFeatureLayer and AGSServiceFeatureTable work together to request, cache locally, and display features on a map.

   • Operational layers are map layers that users can interact with and appear overlaid on top of the basemap.

   • The trail heads feature service was created in advance for this tutorial. Review the Style feature layers tutorial to learn how.

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        mapView.map = AGSMap(basemapType: .topographicVector, latitude: 34.09042, longitude: -118.71511, levelOfDetail: 10)
   
        // *** ADD ***
        let featureServiceURL = URL(string: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trailheads/FeatureServer/0")!
        let trailheadsTable = AGSServiceFeatureTable(url: featureServiceURL)
        mapView.map!.operationalLayers.add(AGSFeatureLayer(featureTable: trailheadsTable))

2. Press Command-R to run the app in the iOS Simulator.

   More info

   Other ways to run the project in Xcode:

   • In Xcode's app menu, select Product > Run.
   • Press the Run button at the top-left of the Xcode project window.

Congratulations, you're done!

The app should run and show features displayed on top of a basemap. Compare your solution with our completed solution project.