Internationalization (i18n) in Flutter: Supporting multiple languages.

In the world of apps, it’s essential to support multiple languages. Flutter’s robust and dynamic internationalization (i18n) makes this a breeze. With easy-to-use packages and widgets, you can build an app that resonates with users from all around the globe. This article serves as a step-by-step guide to implementing i18n in Flutter and managing locale changes dynamically.

Implementing i18n in Flutter: A Step-by-Step Guide

Flutter simplifies how you add multiple language support for your app. It does this using internationalization widgets and packages. To get started, set up the intl package (add it to your pubspec.yaml and run flutter pub get). Then, create a file with the extension .arb (Application Resource Bundle) for each language (very similar to JSON). Ensure that there are key-value pairs for text strings used in your app.

When generating Dart files from the ARB files using intl_translation package, the source code automatically maps each key to its translated value. You also need a delegate class that extends LocalizationsDelegate so Flutter knows which language to load based on user settings.

This will inform Flutter about supported languages and how they should load localization data. The next step would be handling directionality for each language: LTR or RTL. With the help of localeResolutionCallback, you can further fine-tune how your app determines which locale should be used by matching it with the system’s locale or letting users manually choose their preferred language within app settings.

Dynamically Managing Locale Changes in Your Flutter App

A great feature of an adaptable and user-friendly app is changing the locale dynamically. This happens when specific widgets reload under new locale settings, thanks to the Localizations widget. Users should be able to change languages within the app through a nice interface where their choice will be saved persistently using shared preferences or something similar lightweight.

Update Locale and Listen to Locale Changes

After users have changed languages, responsibly update your app’s locale and reload localization data accordingly. Use setState method when saving their preference into the local state so they see changes immediately! Also, ensure that your app listens to system locale changes so that it can automatically update its own whenever there is a change. However, do not do this if the user has manually selected another language.

To streamline UI and localization updates, use context and localization delegates as much as possible inside setState methods. For example, accessing current localization data throughout the app  BuildContextto ensure text strings and widgets depending on localized content are always updated in response to locale changes. This way, users will be able to enjoy personalized experiences without seeing outdated information.

Adding i18n Support