Page History

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• Using the "message:" binding expression in a component template
• By injecting the component's Messages object
  In the first case, you may use the message: binding prefix with component parameters, or with template expansions:

<t:layout title="message:page-title">

  ${message:greeting}, ${user.name}!
  
  . . .
</t:layout>

...

You would extend this with a set of properties files:

page-title=Your Account
greeting=Welcome back

Or, perhaps, a French version:

page-title=Votre Compte
greeting=Bienvenue en arriere

Programatically, you may inject your component message catalog into your class, as an instance of the Messages interface:

  @Inject
  private Messages messages;

You could then get() messages, or format() them:

  public String getCartSummary()     
  {
    if (items.isEmpty())
      return messages.get("no-items");
      
    return messages.format("item-summary", _items.size());
  }

The format() option works using a java.util.Formatter, with all the printf-style loveliness you've come to expect:

no-items=Your shopping cart is empty.     
item-summary=You have %d items in your cart.

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@Inject 
private PersistentLocale persistentLocale;

void onActionFromLocaleToggle() {
    if ("en".equalsIgnoreCase(persistentLocale.get().getLanguage())) {
        persistentLocale.set(new Locale("de"));
    } else {
        persistentLocale.set(new Locale("en"));
    }
    return this;
}
public String getDisplayLanguage() {
    return persistentLocale.get().getDisplayLanguage();
}

...

While your application can support any locale (and thus any language) that you want, Tapestry provides only a limited set of translations for its own built-in messages. As of Tapestry 5.3, the following locales have translations provided:

¹ as of Tapestry 5.3.8

Providing translations for Tapestry built-in messages

Fortunately, Tapestry uses all the same mechanisms for its own locale support as it provides for your application. So, to support other locales, just translate the built-in message catalog (property) files yourself:

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<style type="text/css">table.sectionMacro { width: auto; }</style>

To have Tapestry use these new files, just put them in the corresponding package-named directory within your own app (for example, src/main/resources/org/apache/tapestry5/core.properties).

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