Get global data | MapLibre GL JS

Learn how to query global demographic information and display it on a map.

Query demographic data using API key authentication

The ArcGIS GeoEnrichment serviceA GeoEnrichment service is a service that aggregates demographic data and local facts for locations around the world. It is used to provide insight about the people and places near a location. It is hosted by Esri as the ArcGIS GeoEnrichment service and can also be hosted in ArcGIS Enterprise.Learn more provides global demographic data for 170 countries and regions. To get globally available information, you use the KeyGlobalFacts data collectionA data collection is pre-defined and categorized list of analysis variables (data field names) that are used by the GeoEnrichment service.Learn more, which returns information for the total population, total households, average household size, and total population for males and females for a study area.

In this tutorial, use the MapLibre ArcGIS plugin to display a map and ArcGIS REST JS to access the GeoEnrichment service and display global data for Eastern Europe.

Prerequisites

You need an ArcGIS Location Platform or ArcGIS Online account.

Steps

Get the starter app

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

Choose API key authentication if you:

Want the easiest way to get started.
Want to build public applicationsA public application is an application that allows anonymous access without requiring users to sign in with an ArcGIS account. It supports API key or app authentication.Learn more that 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 and secure itemsAn item, also known as a content item, is a resource stored in a portal such as a web map, hosted layer, style, script tool, file, or notebook.Learn more.
Have an ArcGIS Location Platform or ArcGIS Online account.

Choose user authentication if you:

Want to build private applications.
Require application users to sign in with their own ArcGIS accountAn ArcGIS account is an identity with a user type and set of privileges that can access specific ArcGIS products, tools, APIs, services, and resources. The main account types that can be used for development are an ArcGIS Location Platform account, ArcGIS Online account, and ArcGIS Enterprise account. ArcGIS Location Platform and ArcGIS Online accounts are also associated with a subscription.Learn more and access resources their behalf.
Have an ArcGIS Online account.

To learn more about both types of authentication, go to Authentication.

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

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

Set up authentication

Create a new API key credentialAPI key credentials are an item that contains the parameters used to create and manage long-lived access tokens for API key authentication. They are a type of developer credential.Learn more with the correct privileges to get an access token.

Go to the Create an API key tutorial to follow the steps to get an access token with these privilege(s)Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS.Learn more:
- Privileges
  - Location services > Basemaps
  - Location services > Data enrichment

Create a new OAuth credentialOAuth credentials are an item that contains parameters required to implement user authentication or app authentication, including a client_id, client_secret, and redirect URIs. They are a type of developer credential.Learn more to register the application.

Go to the Create OAuth credentials for user authentication tutorial to create an OAuth credential.
Copy the Client ID and Redirect URL from your OAuth credentials item and paste them to a safe location. They will be used in a later step.

Set developer credentials

Use the API key or OAuth developer credentialsDeveloper credentials are a type of item in a portal that contains parameters for authentication. There are two types of developer credentials: API key credentials and OAuth credentials.Learn more so your application can access ArcGIS servicesA service, also known as an ArcGIS service, is software that supports an ArcGIS REST API and provides geospatial functionality or data. A service can be hosted by Esri or in ArcGIS Enterprise.Learn more.

Update the accessToken variable to use your API key.

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    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";
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In both the index.html and callback.html files, replace YOUR_CLIENT_ID and YOUR_REDIRECT_URL with the client ID and redirect URL of your OAuth credentialsOAuth credentials are an item that contains parameters required to implement user authentication or app authentication, including a client_id, client_secret, and redirect URIs. They are a type of developer credential.Learn more.

index.html
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    /* 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
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    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!

Add references to ArcGIS REST JS

Reference the request and demographics modules from ArcGIS REST JS.

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  <head>
    <title>MapLibre ArcGIS tutorial: Query demographic data</title>
    <meta charset="utf-8">
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
    <!-- Load MapLibre GL JS from CDN -->
    <script src="https://unpkg.com/maplibre-gl@5.23.0/dist/maplibre-gl.js"></script>
    <link href="https://unpkg.com/maplibre-gl@5.23.0/dist/maplibre-gl.css" rel="stylesheet">
    <!-- Load MapLibre ArcGIS from CDN -->
    <script src="https://unpkg.com/@esri/maplibre-arcgis@1.1.0/dist/umd/maplibre-arcgis.min.js"></script>

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

    <style>
    html,
    body,
    #map {
      padding: 0;
      margin: 0;
      height: 100%;
      width: 100%;
      font-family: Arial, Helvetica, sans-serif;
      font-size: 14px;
      color: #323232;
    }

    </style>
  </head>
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Update the map position

The GeoEnrichment service has data sources for many countries around the world, including most of Europe. Change the position of the map to center on eastern Europe.

Update the center parameter to [18.88, 47.33] and set zoom to 5.

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    /* 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;

    const map = new maplibregl.Map({
      container: "map", // the id of the div element

      zoom: 5, // starting zoom
      center: [18.88, 47.33] // starting location [longitude, latitude]

    });
    const basemapStyle = maplibreArcGIS.BasemapStyle.applyStyle(map, {
      style: "arcgis/outdoor",
      token: accessToken
    });
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Add a click event handler

You need a locationA location is a position or region (point, line, or polygon) on the earth's surface.Learn more before calling the GeoEnrichment service. To get a location, you can add a handler to the Map's click event. The click handler will be called with an object containing a LngLat.

You can change the mouse cursor to a crosshair to make it easier to click precisely. Use map.getCanvas to get the canvas, then modify its style property.

After the map initialization code, set the mouse cursor style to crosshair.

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    const map = new maplibregl.Map({
      container: "map", // the id of the div element

      zoom: 5, // starting zoom
      center: [18.88, 47.33] // starting location [longitude, latitude]

    });
    const basemapStyle = maplibreArcGIS.BasemapStyle.applyStyle(map, {
      style: "arcgis/outdoor",
      token: accessToken
    });

    map.getCanvas().style.cursor = "crosshair";
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Add an async handler for the click event.

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    map.getCanvas().style.cursor = "crosshair";

    map.on("click", async (e) => {
      // e.lngLat contains the clicked location

    });
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Execute the query

You pass one or more study areas to queryDemographicData to specify the location of your query. To query a buffer around a point, pass a geometry object with x and y parameters. The default search radius is one mile.

Create a new authentication object from your access token.

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    const map = new maplibregl.Map({
      container: "map", // the id of the div element

      zoom: 5, // starting zoom
      center: [18.88, 47.33] // starting location [longitude, latitude]

    });
    const basemapStyle = maplibreArcGIS.BasemapStyle.applyStyle(map, {
      style: "arcgis/outdoor",
      token: accessToken
    });

    const authentication = arcgisRest.ApiKeyManager.fromKey(accessToken);
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Inside the click handler, call queryDemographicData. Set the studyAreas parameter to a pointA point is a type of geometry containing a single set of x,y coordinates and a spatial reference.Learn more geometry made from the event's lngLat property. Set the dataCollections parameter to to ["KeyGlobalFacts"] to obtain global data.

queryDemographicData is an asynchronous function. Using await, and declaring the click handler async, means the rest of the click handler will wait for a response from the GeoEnrichment service before continuing.

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    map.on("click", async (e) => {
      // e.lngLat contains the clicked location

      const response = await arcgisRest.queryDemographicData({
        studyAreas: [
          {
            geometry: {
              x: e.lngLat.lng,
              y: e.lngLat.lat
            }
          }
        ],
        dataCollections: ["KeyGlobalFacts"],
        authentication: authentication
      });

    });
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Show a pop-up

If the query is successful, the response will contain a results array with a value containing a FeatureSet. The FeatureSet contains attributes such as population within the study area, the number of males and females, and the average household size. A message will display if there is no data available for a location selected.

You can use a pop-up to show the results of the query at the location where you clicked on the map.

To add a pop-up to the map, you use the Popup class in MapLibre GL JS. See the Display a pop-up tutorial for more information.

Set a variable containing the contents of the pop-up, using values from the query response.

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      const response = await arcgisRest.queryDemographicData({
        studyAreas: [
          {
            geometry: {
              x: e.lngLat.lng,
              y: e.lngLat.lat
            }
          }
        ],
        dataCollections: ["KeyGlobalFacts"],
        authentication: authentication
      });

      let message;
      const featureSet = response.results[0].value.FeatureSet;
      if (featureSet.length > 0 && featureSet[0].features.length > 0) {
        const attributes = featureSet[0].features[0].attributes;
        message =
          "<b>Data for a 1 mile search radius</b><br>" +
          [
            `Population: ${attributes.TOTPOP.toLocaleString()}`,
            `Males: ${attributes.TOTMALES.toLocaleString()}`,
            `Females: ${attributes.TOTFEMALES.toLocaleString()}`,
            `Average household size: ${attributes.AVGHHSZ}`
          ].join("<br>");

      } else {
        message = "Data not available for this location.";
      }
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Create a Popup to display a message containing demographic attributes, and add it to the map at the clicked location.

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      } else {
        message = "Data not available for this location.";
      }

      return new maplibregl.Popup().setHTML(message).setLngLat(e.lngLat).addTo(map);
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Run the app

Run the app.

You should now see a map centered over eastern Europe. Click on the map to query for demographic data and view the results in a popup.

What's next?

Learn how to use additional location services in these tutorials:

Map of New York City showing a local data summary for a defined search area.

Get local data

Query regional facts and spending trends for a study area in the United States.

Search for an address

Find an address or place using a search box.

Map highlighting features returned from a SQL attribute query.

Query a feature layer (SQL)

Execute a SQL query to access polygon features from a feature layer.