Change language labels

Learn how to change language labels in a map.

Change language labels using API key authentication

The ArcGIS Basemap Styles service provides a number of different styles that you can use in your OpenLayers applications. Each style accepts a language parameter, which allows you to localize place labels. There are currently over 30 different languages available.

In this tutorial, you use a <select> dropdown menu to toggle between a number of different place label languages.

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 applications that access ArcGIS Location Services and secure items.
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 account 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 credential with the correct privileges to get an access token.

Go to the Create an API key tutorial and create an API key with the following privilege(s):
- Privileges
  - Location services > Basemaps

Set developer credentials

Use the API key or OAuth developer credentials so your application can access ArcGIS services.

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 credentials.

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!

Remove basemap references

Remove the basemapId, basemapURL, and the olms function.

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    <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: "https://www.arcgis.com/sharing/rest" // Your portal URL
    // })

    // const accessToken = session.token;

    const map = new ol.Map({ target: "map" });

    map.setView(
      new ol.View({
        center: ol.proj.fromLonLat([-20, 30]),
        zoom: 3
      })
    );

    const basemapId = "arcgis/outdoor";

    const basemapURL = `https://basemapstyles-api.arcgis.com/arcgis/rest/services/styles/v2/styles/${basemapId}?token=${accessToken}`;

    olms.apply(map, basemapURL)

      .then(() => {
        // Add Esri attribution
        // Learn more in https://esriurl.com/attribution
        const source = map.getLayers().item(0).getSource();
        const poweredByEsriString = "Powered by <a href='https://www.esri.com/en-us/home' target='_blank'>Esri</a> | ";

        const attributionFn = source.getAttributions();
        if (attributionFn) {
          source.setAttributions((ViewStateLayerStateExtent) => {
            return [poweredByEsriString, ...attributionFn(ViewStateLayerStateExtent)];
          });
        } else source.setAttributions(poweredByEsriString);

      });

    </script>
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Add a language selector

Add a menu that allows users to change the display language of your map. OpenLayers does not have a built-in selector widget, so you will create an HTML <select> element.

In the <head> tag, add CSS that will position the <select> menu wrapper element in the upper right corner and provide styling.

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


    #languages-wrapper {
      position: absolute;
      top: 20px;
      right: 20px;
    }

    #languages {
      font-size: 16px;
      padding: 4px 8px;
    }


    </style>
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In the <body> element, add the wrapper tag with an id of languages-wrapper.

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  <body>
    <div id="map"></div>

    <div id="languages-wrapper">

    </div>
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In the wrapper element, add a <select> element, which you will populate in a later step.

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    <div id="languages-wrapper">

      <select id="languages"></select>

    </div>
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Set the initial language

When the page loads, initialize the app to initially display in Ukrainian.

Create a function called url that creates the URL for a basemap style.

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    <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;

    const map = new ol.Map({ target: "map" });
    map.setView(
      new ol.View({
        center: ol.proj.fromLonLat([48.8790, 35.7088]),
        zoom: 3
      })
    );

    const baseUrl = "https://basemapstyles-api.arcgis.com/arcgis/rest/services/styles/v2/styles";
    const url = (language) => `${baseUrl}/arcgis/outdoor?token=${accessToken}&language=${language}`;
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Create a function called setLanguage that will clear existing basemap layers and use olms to instantiate a basemap layer in the new language.

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    const baseUrl = "https://basemapstyles-api.arcgis.com/arcgis/rest/services/styles/v2/styles";
    const url = (language) => `${baseUrl}/arcgis/outdoor?token=${accessToken}&language=${language}`;

    const setLanguage = (language) => {
      // Clear out existing layers.
      map.setLayerGroup(new ol.layer.Group());
      // Instantiate the given basemap layer.
      olms.apply(map, url(language))
        .then(() => {
          // Add Esri attribution
          // Learn more in https://esriurl.com/attribution
          const source = map.getLayers().item(0).getSource();
          const poweredByEsriString = "Powered by <a href='https://www.esri.com/en-us/home' target='_blank'>Esri</a> | ";

          const attributionFn = source.getAttributions();
          if (attributionFn) {
            source.setAttributions((ViewStateLayerStateExtent) => {
              return [poweredByEsriString, ...attributionFn(ViewStateLayerStateExtent)];
            });
          } else source.setAttributions(poweredByEsriString);

        });
    };
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Access the <select> element using its id.

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    const basemapsSelectElement = document.querySelector("#languages");
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Import arcgisRest.request() to make a request to the Basemap Styles service. This dynamically fetches the available basemap languages and populates the select element.

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

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    arcgisRest.request(`${baseUrl}/self`, {
      httpMethod: "GET"
    }).then((response) => {
      response.languages.forEach((language) => {
        const option = document.createElement("option");
        option.value = language.code;
        option.textContent = language.name;
        basemapsSelectElement.appendChild(option);
      });

    });
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Call setLanguage to initialize the basemap layer to the Ukrainian (uk) enumeration.

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    arcgisRest.request(`${baseUrl}/self`, {
      httpMethod: "GET"
    }).then((response) => {
      response.languages.forEach((language) => {
        const option = document.createElement("option");
        option.value = language.code;
        option.textContent = language.name;
        basemapsSelectElement.appendChild(option);
      });

      setLanguage(response.languages[0].code);

    });
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Add an event listener

Call setLanguage when the user selects an option in the <select> menu.

Add an event listener that calls setLanguage when the <select> element is changed.

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    const basemapsSelectElement = document.querySelector("#languages");

    arcgisRest.request(`${baseUrl}/self`, {
      httpMethod: "GET"
    }).then((response) => {
      response.languages.forEach((language) => {
        const option = document.createElement("option");
        option.value = language.code;
        option.textContent = language.name;
        basemapsSelectElement.appendChild(option);
      });

      setLanguage(response.languages[0].code);

    });

    basemapsSelectElement.addEventListener("change", (e) => {
      setLanguage(e.target.value);
    });
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