Reverse geocode

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

Reverse geocoding is the process of converting a location to an address or place. To reverse geocode, 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. To simplify accessing the Geocoding service, you use the locator module.

In this tutorial, you will use the locator to reverse geocode and find the closest address to your clicked location on the map.

Prerequisites

Steps

Create a new pen

To get started, either complete the Display a map tutorial or .

Get an access token

You need an access token with the correct privileges to access the location services 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

In CodePen, set esriConfig.apiKey to your access token.

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  var esriConfig = {
    apiKey: "YOUR_ACCESS_TOKEN",
  };

To learn about other ways to get an access token, go to Types of authentication.

Update the map

A streets basemap layer is typically used in geocoding applications. Update the basemap attribute to use the arcgis/navigation basemap layer and change the position of the map to center on Quito.

Update the basemap attribute from arcgis/topographic to arcgis/navigation. Then, update the center attribute to -78.50169,-0.21489, and set the zoom attribute to 12.

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    <arcgis-map basemap="arcgis/navigation" center="-78.50169, -0.21489" zoom="12">

      <arcgis-zoom position="top-left"></arcgis-zoom>

    </arcgis-map>
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Add modules and event listener

Add a <script> tag in the <body> following the <arcgis-map> component. Use $arcgis.import() to add the locator module.

The ArcGIS Maps SDK for JavaScript is available via CDN and npm, but this tutorial is based on CDN. The $arcgis.import global function accepts a module path or array of module paths, and returns a promise that resolves with the requested modules. This function can only be used when working with the CDN; otherwise, use the standard import syntax. To learn more about the SDK's different modules, visit the References page.

Use the document.querySelector() method to access the map component.
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    <script type="module">

      const locator = await $arcgis.import("@arcgis/core/rest/locator.js");


      const viewElement = document.querySelector("arcgis-map");


    </script>
```
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Create an event listener to listen for the map component's arcgisViewReadyChange event.

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    <script type="module">

      const locator = await $arcgis.import("@arcgis/core/rest/locator.js");

      const viewElement = document.querySelector("arcgis-map");

      viewElement.addEventListener("arcgisViewReadyChange", () => {

      });

    </script>
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Define service url

Use the locator module to access the Geocoding service and the reverseGeocode operation.

Define a variable, serviceUrl, to reference the Geocoding service.

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      viewElement.addEventListener("arcgisViewReadyChange", () => {

        const serviceUrl = "http://geocode-api.arcgis.com/arcgis/rest/services/World/GeocodeServer";

      });
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Reverse geocode

Use an event listener to capture a click location on the map and then call the Geocoding service. The service returns an address if an address is found, or an error if it cannot find a result. Display the results in a pop-up with the latitude, longitude, and address.

In the arcgisViewReadyChange event listener, add an arcgisViewClick event handler to the map component. Create params and set the location to evt.detail.mapPoint.

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        const serviceUrl = "http://geocode-api.arcgis.com/arcgis/rest/services/World/GeocodeServer";

        viewElement.addEventListener("arcgisViewClick", (evt) => {
          const params = {
            location: evt.detail.mapPoint,
          };

        });
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Create a showAddress function to display coordinates and the corresponding address within a pop-up.

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        viewElement.addEventListener("arcgisViewClick", (evt) => {
          const params = {
            location: evt.detail.mapPoint,
          };

        });

        function showAddress(address, pt) {
          viewElement.openPopup({
            title:
              +Math.round(pt.longitude * 100000) / 100000 +
              ", " +
              Math.round(pt.latitude * 100000) / 100000,
            content: address,
            location: pt,
          });
        }
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Update the arcgisViewClick handler to call locationToAddress to reverse geocode the mapPoint. Use the showAddress function to display a pop-up with the results.

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        viewElement.addEventListener("arcgisViewClick", (evt) => {
          const params = {
            location: evt.detail.mapPoint,
          };

          locator.locationToAddress(serviceUrl, params).then(
            (response) => {
              // Show the address found
              const address = response.address;
              showAddress(address, evt.detail.mapPoint);
            },
            (error) => {
              // Show no address found
              showAddress("No address found.", evt.detail.mapPoint);
            },
          );

        });
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Run the App

In CodePen, run your code to display the map.

Click on the map to reverse geocode a location and return a pop-up with the closest address.

What's next?

Learn how to use additional API features and ArcGIS services in these tutorials: