Tutorial: localization_detection


With an Argos app you have four included index files:

index.html, index-dev.html, index.aspx and index-dev.aspx.

Namely two files each for dev and production - the difference lies in the file extension and thereby the way it adds in the needed localization.

HTML Files

The *.html files hard-code the localization:

require([application].concat(configuration), function(application, configuration) {
    var localization = [

Which includes two localization pieces:

  • Top Level: localization/en which is for currency, decimal and thousands symbols, etc; and
  • App Strings: localization/appname/en which is the translated strings .js file from Argos-Localizer.

ASPX Files

The *.aspx files use server side code for detecting the localization of the browser and dynamically include the needed localization paths:

require([application].concat(configuration), function(application, configuration) {
    var localization = <%= Serialize(
            .Select(item => item.Path.Substring(0, item.Path.Length - 3))
    ) %>;

Note that the C# code gets the browsers locale meaning depending on which browser you use the locale may be set in the browser itself, the operating system you are running, or even a plugin.

Adding a New Language

To add a new language you need to have both the "top level" and the "app strings" pieces:

localization/klingon.js and localization/appname/klingon.js

Top Level

To define a new top level localization piece:

1. Download a sample top level

2. Rename to the proper ISO 3166 code. Note that the locale detection performs a fall- back to generic locale (browser detects de-DE, doesn't find de-DE.js so it tries de.js which is successful).

3. Edit the file, making sure to change the define path:

    define('localization/en', ['dojo/_base/lang'], function(lang) {


    define('localization/klingon', ['dojo/_base/lang'], function(lang) {

4. Save and drop into the products/appname/localization/ folder.

App Strings

1. Follow either Localization Example or the Argos-Localizer code directly on Github.

2. Take the resulting .js file and drop it into the products/appname/localization/appname/ folder.


There are two approaches depending on what tools you want to use:

1. Edit the .html file; or

2. Change the browser locale and use .aspx.

Note that in both cases if you don't see a change right away that means you should a) clear your cache or b) close all browser instances and restart it (in the case of approach 2).

Editing the HTML File

Testing using the hard coded HTML file is the easiest and most direct approach:

1. Change the default English locale:

require([application].concat(configuration), function(application, configuration) {
    var localization = [

to your added locale

require([application].concat(configuration), function(application, configuration) {
    var localization = [

2. Save and open the file.

Changing the Browser Locale

To use the .aspx file auto-detection you need to alter the browsers locale.

Chrome (Windows)

1. Create a shortcut to Chrome

2. Right-click, edit Properties

3. Add to the Target field:

path_to_chrome.exe --lang=klingon

4. Optionally, you may add:


This saves all the chrome data to a new profile and not your default one.

There is also a way under the Wrench but it is several levels deep, a shortcut is easier to maintain multiple languages and you can add more command line options to point to your file, enable extra logging and other features.

Chrome (Mac)

No option available besides changing:

1. From the Apple Menu choose System Preferences;

2. Then under Personal select International;

3. Set the locale;

4. Restart all browser sessions.


Since FireFox has an excellent extension API it is possible to alter the locale directly via a plugin:

Quick Locale Switcher

1. Install and load the plugin.

2. After opening the page, use the plugins icon to change the locale.


1. Click the gears icon and select Internet options;

2. In the General tab, at the bottom, click Languages; and

3. Add the locale and move it to the very top. Click Ok.