Tutorial: Reverse geocode

Learn how to find an address near a location with the geocoding service.

Reverse geocode coordinates to addresses with the geocoding service using API key authentication

Reverse geocoding is the process of converting a location to an address or place. To reverse geocode, you use the geocoding service and the reverseGeocode operation. This operation requires an initial location and returns an address with attributes such as place name and location.

Prerequisites

An ArcGIS Location Platform or ArcGIS Online account.

Steps

Get the starter app

Select a type of authentication below and follow the steps to create a new application.

You can choose one of the following to create a new CodePen:

Option 1: Complete the Display a scene tutorial; or,
Option 2: Start from the Display a scene tutorial .

Set up authentication

Create developer credentials in your portal for the type of authentication you selected.

Create a new API key credential with the correct privileges to access the resources used in this tutorial.

Go to the Create an API key tutorial and create an API key with the following privilege(s):
- Privileges
  - Location services > Basemaps
  - Location services > Geocoding
Copy the API key access token to your clipboard when prompted.

Set developer credentials

Use the API key or OAuth developer credentials created in the previous step in your application.

Add <script> elements in the HTML <body> and create an accessToken variable to store your access token. Set YOUR_ACCESS_TOKEN with the access token you previously copied from your API key credentials.

Expand
Use dark colors for code blocks
  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

  </script>
Expand

Set the defaultAccessToken included with Cesium to authenticate requests to the ArcGIS services used in this tutorial.

Expand
Use dark colors for code blocks
  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

    Cesium.ArcGisMapService.defaultAccessToken = accessToken;

  </script>
Expand

In both the index.html and callback.html files, set the properties of clientId and redirectUri with the client ID and redirect URL of your OAuth credentials.

index.html
Use dark colors for code blocks
    /* Use for user authentication */
    const clientId = "YOUR_CLIENT_ID"; // Your client ID from OAuth credentials
    const redirectUri = "YOUR_REDIRECT_URI"; // The redirect URL registered in your OAuth credentials
    const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
      clientId,
      redirectUri,
      portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    })

    const accessToken = session.token;

callback.html
Use dark colors for code blocks
    arcgisRest.ArcGISIdentityManager.completeOAuth2({
      clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
      redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
      portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    })

Run the app and ensure you can sign in successfully.

If you are unable to sign in, make sure you have the correct redirect URL and port. This URL varies based on your application and typically takes the format of https://<server>[:port]/callback.html or http://my-arcgis-app:/auth. For example, if you are running an application on http://127.0.0.1:5500/, set http://127.0.0.1:5500/callback.html as your redirect URL in the index.html and callback.html file and your developer credential. They all have to match!

Set the defaultAccessToken included with Cesium to authenticate requests to the ArcGIS services used in this tutorial.

index.html
Use dark colors for code blocks
    Cesium.ArcGisMapService.defaultAccessToken = accessToken;

Get a Cesium ion access token

All Cesium applications must use an access token provided through Cesium ion. This token allows you to access assets such as Cesium World Terrain in your application.

Go to your Cesium ion dashboard to generate an access token. Copy the key to your clipboard.

Create a cesiumAccessToken variable and replace YOUR_CESIUM_ACCESS_TOKEN with the access token you copied from the Cesium ion dashboard.

Use dark colors for code blocks
  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

    // or

    /* Use for user authentication */
    // const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
    //   clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
    //   redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
    //   portal: "YOUR_PORTAL_URL" // Your portal URL
    // })

    // const accessToken = session.token;

    Cesium.ArcGisMapService.defaultAccessToken = accessToken;

    const cesiumAccessToken = "YOUR_CESIUM_ACCESS_TOKEN";

  </script>

Configure Cesium.Ion.defaultAccessToken with the Cesium access token to validate the application.

Use dark colors for code blocks
  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

    // or

    /* Use for user authentication */
    // const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
    //   clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
    //   redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
    //   portal: "YOUR_PORTAL_URL" // Your portal URL
    // })

    // const accessToken = session.token;

    Cesium.ArcGisMapService.defaultAccessToken = accessToken;

    const cesiumAccessToken = "YOUR_CESIUM_ACCESS_TOKEN";

    Cesium.Ion.defaultAccessToken = cesiumAccessToken;

  </script>

Add references to ArcGIS REST JS

In the <head> element, reference the geocoding and request packages from ArcGIS REST JS.

Expand
Use dark colors for code blocks
    <script src="https://cesium.com/downloads/cesiumjs/releases/1.128/Build/Cesium/Cesium.js"></script>
    <link href="https://cesium.com/downloads/cesiumjs/releases/1.128/Build/Cesium/Widgets/widgets.css" rel="stylesheet">

    <script src="https://unpkg.com/@esri/arcgis-rest-request@4/dist/bundled/request.umd.js"></script>
    <script src="https://unpkg.com/@esri/arcgis-rest-geocoding@4/dist/bundled/geocoding.umd.js"></script>

Expand

Update the scene

CesiumJS supports both 3D models and geocoding. Update the scene to display 3D buildings so you can visualize results from the geocoding service.

Update the scene view to center on location [-122.4117, 37.769, 2000] in San Francisco, CA and change the orientation heading to -130.

Use dark colors for code blocks
        viewer.camera.setView({

            destination: Cesium.Cartesian3.fromDegrees(-122.388805, 37.797517, 2000),

            orientation: {

                heading: Cesium.Math.toRadians(-130),

                pitch: Cesium.Math.toRadians(-70.0),
            }
        });

Initialize a terrain provider called geoidService that references the Earth Gravitational Model EGM2008. This provider will allow for geoid conversion between the gravity-based 3D object layer and the ellipsoidal-based Cesium World Terrain.

Expand
Use dark colors for code blocks
        const geoidService = await Cesium.ArcGISTiledElevationTerrainProvider.fromUrl("https://tiles.arcgis.com/tiles/GVgbJbqm8hXASVYi/arcgis/rest/services/EGM2008/ImageServer");

Expand

Add the data attribution for the elevation layer source.

Go to the EGM2008 item.
Scroll down to the Credits (Attribution) section and copy its value.

Create an attribution property and paste the attribution value from the item.

Expand
Use dark colors for code blocks
        const geoidService = await Cesium.ArcGISTiledElevationTerrainProvider.fromUrl("https://tiles.arcgis.com/tiles/GVgbJbqm8hXASVYi/arcgis/rest/services/EGM2008/ImageServer");

        // Attribution text retrieved from https://arcgis.com/home/item.html?id=d798c71512404bbb9c1551b827bf5467
        viewer.creditDisplay.addStaticCredit(new Cesium.Credit("National Geospatial-Intelligence Agency (NGA)", false));

Expand

Add the San Francisco 3D Buildings scene layer to visualize the city of San Francisco.

Expand
Use dark colors for code blocks
        const geoidService = await Cesium.ArcGISTiledElevationTerrainProvider.fromUrl("https://tiles.arcgis.com/tiles/GVgbJbqm8hXASVYi/arcgis/rest/services/EGM2008/ImageServer");

        // Attribution text retrieved from https://arcgis.com/home/item.html?id=d798c71512404bbb9c1551b827bf5467
        viewer.creditDisplay.addStaticCredit(new Cesium.Credit("National Geospatial-Intelligence Agency (NGA)", false));

        const i3sProvider = await Cesium.I3SDataProvider.fromUrl("https://tiles.arcgis.com/tiles/z2tnIkrLQ2BRzr6P/arcgis/rest/services/SanFrancisco_Bldgs/SceneServer", {
            geoidTiledTerrainProvider: geoidService
        });
        viewer.scene.primitives.add(i3sProvider);

Expand

Add the data attribution for the scene layer source.

Go to the San Francisco 3D Objects item.
Scroll down to the Credits (Attribution) section and copy its value.

Create an attribution property and paste the attribution value from the item.

Expand
Use dark colors for code blocks
        const geoidService = await Cesium.ArcGISTiledElevationTerrainProvider.fromUrl("https://tiles.arcgis.com/tiles/GVgbJbqm8hXASVYi/arcgis/rest/services/EGM2008/ImageServer");

        // Attribution text retrieved from https://arcgis.com/home/item.html?id=d798c71512404bbb9c1551b827bf5467
        viewer.creditDisplay.addStaticCredit(new Cesium.Credit("National Geospatial-Intelligence Agency (NGA)", false));

        const i3sProvider = await Cesium.I3SDataProvider.fromUrl("https://tiles.arcgis.com/tiles/z2tnIkrLQ2BRzr6P/arcgis/rest/services/SanFrancisco_Bldgs/SceneServer", {
            geoidTiledTerrainProvider: geoidService
        });
        viewer.scene.primitives.add(i3sProvider);

        // Attribution text retrieved from https://www.arcgis.com/home/item.html?id=d3344ba99c3f4efaa909ccfbcc052ed5
        viewer.creditDisplay.addStaticCredit(new Cesium.Credit("Precision Light Works (PLW)", false));
Expand

Call the geocoding service

Create a new arcgisRest.ApiKeyManager using your access token to authenticate requests to the geocoding service.

Use dark colors for code blocks
        const authentication = arcgisRest.ApiKeyManager.fromKey(accessToken);

Define a function called findAddress that takes coordinates (longitude and latitude) as a parameter. Use arcgisRest.reverseGeocode to retrieve address information for the given coordinates.

Expand
Use dark colors for code blocks
        function findAddress(coordinates) {
            arcgisRest
                .reverseGeocode(coordinates, {
                    authentication
                })

                .then((response) => {

                })

        }
Expand

Inside the then block of the reverseGeocode call, create a pin builder using Cesium.PinBuilder. This will allow you to create map markers for the coordinates.

Expand
Use dark colors for code blocks
        function findAddress(coordinates) {
            arcgisRest
                .reverseGeocode(coordinates, {
                    authentication
                })

                .then((response) => {

                    const pinBuilder = new Cesium.PinBuilder();

                })

        }
Expand

Add a billboard at the clicked coordinates on the map. Extract the location from the response and add it to the Cesium viewer as an entity.

Expand
Use dark colors for code blocks
        function findAddress(coordinates) {
            arcgisRest
                .reverseGeocode(coordinates, {
                    authentication
                })

                .then((response) => {

                    const pinBuilder = new Cesium.PinBuilder();

                    const location = Cesium.Cartesian3.fromDegrees(response.location.x, response.location.y);
                    const result = viewer.entities.add({
                        name: `${response.location.x.toLocaleString()}, ${response.location.y.toLocaleString()}`,
                        description: `${response.address.LongLabel}`,
                        position: location,

                        billboard: {
                            verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
                            heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
                            scale: 0.6,
                            image: pinBuilder.fromColor(Cesium.Color.fromCssColorString('#5491f5'), 48).toDataURL(),
                        }

                    })
                    viewer.selectedEntity = result;

                })

        }
Expand

Add a click handler

Define a function called onLeftClick that handles user clicks on the map. This function will be triggered whenever a LEFT_CLICK event occurs. Use Cesium.ScreenSpaceEventType.LEFT_CLICK to register the event type.

Expand
Use dark colors for code blocks
        function onLeftClick(movement) {

        }

        viewer.screenSpaceEventHandler.setInputAction(onLeftClick, Cesium.ScreenSpaceEventType.LEFT_CLICK);
Expand

Inside onLeftClick, update the coordinates of the clicked point. Remove any previously selected points (if any). Convert the clicked screen position into geographic coordinates.

Expand
Use dark colors for code blocks
        function onLeftClick(movement) {

            viewer.entities.removeAll();
            const pickedPosition = viewer.scene.pickPosition(movement.position);

            const cartographic = Cesium.Cartographic.fromCartesian(pickedPosition);
            const originLatLng = [Cesium.Math.toDegrees(cartographic.longitude), Cesium.Math.toDegrees(cartographic.latitude)]

        }

        viewer.screenSpaceEventHandler.setInputAction(onLeftClick, Cesium.ScreenSpaceEventType.LEFT_CLICK);
Expand

Pass the latitude and longitude values obtained from the click event to the findAddress function. This will send a request to the geocoding service to retrieve the address for the clicked location.

Expand
Use dark colors for code blocks
        function onLeftClick(movement) {

            viewer.entities.removeAll();
            const pickedPosition = viewer.scene.pickPosition(movement.position);

            const cartographic = Cesium.Cartographic.fromCartesian(pickedPosition);
            const originLatLng = [Cesium.Math.toDegrees(cartographic.longitude), Cesium.Math.toDegrees(cartographic.latitude)]

            findAddress(originLatLng);

        }

        viewer.screenSpaceEventHandler.setInputAction(onLeftClick, Cesium.ScreenSpaceEventType.LEFT_CLICK);
Expand