Weblate Spring

Provides a Spring MessageSource backed by a Weblate Server.

Usage

Add the Maven dependency to your project (find the current version on Maven Central):

<dependency>
  <groupId>at.porscheinformatik.weblate</groupId>
  <artifactId>weblate-spring</artifactId>
  <version>${weblate-spring.version}</version>
</dependency>

Then declare the WeblateMessageSource as a bean. You can configure the MessageSource via:

• baseUrl (required) - the base URL of your Weblate instance
• project (required) - the project slug
• component (required) - the component slug

Usually you might want to have the local message bundles as a backup when Weblate is not running. Therefore, you can set a ResourceBundleMessageSource as the parent of the WeblateMessageSource.

WeblateMessageSource implements an interface AllPropertiesSource which can be used to obtain all translations from the message source. This is needed when you want to get all your translations to your client (for example in a Single Page App). The AllPropertiesReloadableResourceBundleMessageSource should also be used in this context.

The implementation can also be switched to use asynchronous loading. In this case the texts will be loaded in a separate thread in the background. This means that the first time you get a property it will fall-back to the parent MessageSource. As soon as the loading is done the new translated texts will be available.

Here is a full example bean configuration for a Spring Boot app (with "messages" as the default bundle):

@Bean
@Primary
public WeblateMessageSource messageSource() {
  var weblateMessageSource = new WeblateMessageSource();
  weblateMessageSource.setBaseUrl("https://hosted.weblate.org");
  weblateMessageSource.setProject("my-project");
  weblateMessageSource.setComponent("my-component");
  weblateMessageSource.useAuthentication("api-key");
  weblateMessageSource.setAsync(true); // <- set this for asynchronous loading
  weblateMessageSource.setParentMessageSource(localMessageSource());
  return weblateMessageSource;
}

@Bean
MessageSource localMessageSource() {
  var localMessageSource = new AllPropertiesReloadableResourceBundleMessageSource();
  localMessageSource.setDefaultEncoding(StandardCharsets.UTF_8.name());
  localMessageSource.setBasename("messages");
  localMessageSource.setFallbackToSystemLocale(false);
  return localMessageSource;
}

Authentication / Adapting RestTemplate

For the simple authentication via API key you can use WeblateMessageSource#useAuthentication. If you want further customization of the HTTP calls you can set your own RestTemplate.

Caching

WeblateMessageSource caches loaded translations 30 minutes (this can be changed by setting maxAgeMilis). If you want to update one locale immediately call WeblateMessageSource#reload(Locale).

If you want to fully clear the cache call WeblateMessageSource#clearCache - this will also reload the languages. Please use this with caution as it add heavy load to the Weblate API!