Localization and Internationalization in Android

Localization is the process of modeling applications to a specific locale, market, or device. Localization can also be regarded as language translation. <!--more--> Globalization is a term used in a wide variety of contexts such as transport and trade.

In the field of technology, globalization is defined as the process of building and developing a software product that functions in multiple cultures and locales.

In other words, the software can serve a diverse group of people.

Internationalization is the process of localizing and globalizing your application.

Table of contents #

• Introduction
• Prerequisites
• Goals
• Configuration types and qualifiers values
• Syntax to specify qualifier values
• Localization resources in Android
• How the SDK handles localized resources
• Localizing strings
• Localizing images
• Precautions when localizing your application
• Conclusion
• Further reading

Prerequisites #

• Have Android Studio IDE installed.
• Basic knowledge of Extensible Markup Language (XML).
• Have an understanding of the Android Studio project structure.

Goals #

At the end of the tutorial, the reader should understand the localization process in Android applications.

Configuration types and qualifiers values #

Configuration types #

Configuration types are the factors to consider when localizing your application. They include:

• Language and region - The context in which the application is being utilized.
• Mobile country code and Mobile network code - This is a three-digit number that is always specific for a given country and network provider.
• Layout direction can be vertical or horizontally oriented.
• Time - You can use specific features for a different time range.
• Screen pixel density.
• Navigation key available.
• Primary text input method.
• Platform version.
• UI mode.

Qualifiers values #

Qualifier values are the communication paths in Android that notify the system of the different factors to react to by providing alternate resources.

Syntax to specify qualifier values #

<resource_name> - <config-qualifiers>

• drawable-fr - fr is a configuration qualifier for french.
• layout-sw - sw is a configuration qualifier for swahili.

Localization resources in Android #

The resource directory (res) is the parent folder to all resources in Android. Each resource is placed in a specific subdirectory.

These subdirectories are:-

• animator - This is an XML file that defines animation properties.
• anim - It is an XML file that defines tween animations.
• color - This is an XML file that defines a list of colors.
• drawable - It is a Bitmap file (png, jpg, gif) or XML file which holds pictures.
• mipmap - This is a drawable file for different launcher icon densities.
• layout - It is an XML file that defines a user interface layout.
• menu - It defines the application menus.
• raw - It holds arbitrary files that are saved in raw form.
• values - It is an XML that contains simple values such as strings, integers, and color.
• xml - This holds arbitrary XML files that can be read at runtime, by calling the resource.getXml() method.

To understand how each resource is localized, it's crucial to know the resource groups.

How to access the resources:

1. Class #

[<res_directory>].<resource-type>.<Resource_name>

Examples:

• R.layout.activity-main
• R.String.main

2. XML file #

@<resource-type>/<resource-name>

Examples:

• @String/word
• @color/blue

How the SDK handles localized resources #

Android selects localized resources to use based on the current device settings. The procedure is as follows:

• The SDK eliminates qualifiers that contradict the device settings.
• Then identifies the next qualifier in the order. If no resource subdirectory uses the qualifier, the subdirectory is also eliminated.
• The process is repeated until the desired resource is left.

Localizing strings #

To localize strings appropriately, do not hard code them. Instead, use string-resource files to create strings value.

Follow the procedure below to localize a string:

Step 1 - Creating a string file #

Right-click on resource subdirectory values, go to new, and select resource files.

Step 2 - Naming string files #

Name the file similar to the available string.xml file on the wizard that appears. Then select locale on the available qualifier and navigate to the path below:

Step 3 - Choosing the language to localize your string #

Choose the language that you wish to localize on the same wizard. You can specify the region if required, then hit OK. An empty string.xml file will be generated.

If you check the string-resource subdirectory, you will notice there are two string.xml files, with one having the specified language symbols.

Step 4 - Writing to the newly created string file #

Finally, open your main string.xml file, copy the available strings, and paste them into the new string.xml file.

Once you have added the code, please do not change the string name to the original strings in the main file.

You should instead change the string value to your desired language.

Localizing images #

An image needs to display the right content according to the context it is being utilized. For this reason, the localization of images should be considered.

This feature can be implemented as follows:

Step 1 - Creating a new image subdirectory #

Right-click on the resource folder and navigate to the new select android resource directory.

Step 2 - Naming newly created image subdirectory #

To avoid confusion the image subdirectory names should be similar. Select drawable on the resource type on the wizard that appears under the available qualifier.

Next, choose locale and press the forward arrows to choose the appropriate qualifier, and then click the OK button.

You will notice that the directory name is appended with the specified qualifier symbol, as shown below:

Step 3 - Locate the drawable subdirectory in your files and add the required image #

Locate the newly created drawable subdirectory and add an image that you wish to display for the specified locale.

Ensure that the image within the new drawable folder has a similar name as that in the original drawable folder.

Step 4 - Running your localized application #

When you run your application, you should see the following output:

Best practices for localization #

• Provide all default resources that need to be localized in your application.

• Do not think of the localization process at the final application development stage.

• Ensure that the qualifier-naming rule is followed. The best way to stick to this naming rule is by creating an alternate resource directory.

• Avoid duplication of resources but rather use aliases instead, which reduces the APK size.

• When doing translation of strings, use professional translation services to make sure that the correct meaning is conveyed.

We also discussed the localization of strings and images, as well as the best practices to follow when localizing your application.

You can access the full code from this GitHub Repository

Further reading #

• Localization and internationalization in Android

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Peer Review Contributions by: Briana Nzivu