Change language labels | OpenLayers

Learn how to change language labels in a map.

Change language labels using API key authentication

The ArcGIS Static Basemap Tiles 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 more than 5 different languages available.

In this tutorial, you use a <select> dropdown menu to toggle between a number of different language labels for the static basemap tiles.

Prerequisites

You need an ArcGIS Location Platform account.

ArcGIS Online and ArcGIS Enterprise accounts are not supported.

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 > Static basemap tiles

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!

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.

Create a <div> tag to contain the <select> dropdown menu, which you will populate in a later step.

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

    <div id="language-wrapper">
      <select id="language"></select>
    </div>

  </body>

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

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

    #language-wrapper {
      position: absolute;
      top: 20px;
      right: 20px;
      background: rgba(255, 255, 255, 0);
    }
    #language {
      font-size: 16px;
      padding: 4px 8px;
    }

Update the map's viewpoint

Change the map's center to [8.90, 47.14] and zoom level to 7. This will focus the map on Switzerland.

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    const map = new ol.Map({
      target: "map",

      view: new ol.View({

        center: ol.proj.fromLonLat([8.90, 47.14]), // Switzerland
        zoom: 7

      })
    });

Set the basemap

When the page loads, initialize the app to display the static basemap tiles in English.

Create a function called url that takes a language as a parameter. This will create the URL of the static basemap tiles for that specified language.

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    const url = (language) => `${baseUrl}/${basemapId}/static/tile/{z}/{y}/{x}?token=${accessToken}&language=${language}`;

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Create a defaultLanguage variable for the basemap, which is en for English.

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    const defaultLanguage = "en";
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Modify the url property of the Tile object to call the url function with defaultLanguage as the default language labels.

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    const tileLayer = new ol.layer.Tile({
      source: new ol.source.XYZ({
        url: url(defaultLanguage),
        tileSize: 512
      })
    });
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Create a languageSelectElement to return the basemap from the selector.

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    const languageSelectElement = document.querySelector("#language");

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Import arcgisRest.request() to make a request to the Static Basemap Tiles 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",
      authentication: arcgisRest.ApiKeyManager.fromKey(accessToken)
    }).then((response) => {
      response.languages.forEach((style) => {
        const option = document.createElement("option");
        option.value = style.code;
        option.textContent = style.name;
        languageSelectElement.appendChild(option);
      });

      tileLayer.getSource().setUrl(url(response.languages[0].code));

    });
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Run the code to ensure the map displays the default static basemap tiles in English and that the <select> element contains different language enumerations.

Add a listener

Use an event listener to register a language change in the <select> element and to update the map.

Add an event listener to store the selected basemap.

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    const languageSelectElement = document.querySelector("#language");

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

      tileLayer.getSource().setUrl(url(response.languages[0].code));

    });

    languageSelectElement.addEventListener("change", (e) => {

    });
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Update the tileLayer's source URL with the new language.

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    const languageSelectElement = document.querySelector("#language");

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

      tileLayer.getSource().setUrl(url(response.languages[0].code));

    });

    languageSelectElement.addEventListener("change", (e) => {

      const language = e.target.value;
      tileLayer.getSource().setUrl(url(language));

    });
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Run the app

Run the app.

Use the controls to switch between language labels.

What's next?

Change the basemap style

Switch a static basemap style on a map.

Display multiple basemap layers

Add multiple basemap layers from different services to your map.