§Messages and internationalization
§Specifying languages supported by your application
A valid language code is specified by a valid ISO 639-2 language code, optionally followed by a valid ISO 3166-1 alpha-2 country code, such as fr
or en-US
.
To start you need to specify the languages supported by your application in the conf/application.conf
file:
application.langs="en,en-US,fr"
§Externalizing messages
You can externalize messages in the conf/messages.xxx
files.
The default conf/messages
file matches all languages. Additionally you can specify language-specific message files such as conf/messages.fr
or conf/messages.en-US
.
You can then retrieve messages using the play.api.i18n.Messages
object:
val title = Messages("home.title")
All internationalization API calls take an implicit play.api.i18n.Lang
argument retrieved from the current scope. You can also specify it explicitly:
val title = Messages("home.title")(Lang("fr"))
Note: If you have an implicit
Request
in the scope, it will provide an implicitLang
value corresponding to the preferred language extracted from theAccept-Language
header and matching one of the application supported languages. You should add aLang
implicit parameter to your template like this:@()(implicit lang: Lang)
.
§Messages format
Messages are formatted using the java.text.MessageFormat
library. For example, assuming you have message defined like:
files.summary=The disk {1} contains {0} file(s).
You can then specify parameters as:
Messages("files.summary", d.files.length, d.name)
§Notes on apostrophes
Since Messages uses java.text.MessageFormat
, please be aware that single quotes are used as a meta-character for escaping parameter substitutions.
For example, if you have the following messages defined:
info.error=You aren''t logged in!
example.formatting=When using MessageFormat, '''{0}''' is replaced with the first parameter.
you should expect the following results:
Messages("info.error") == "You aren't logged in!"
Messages("example.formatting") == "When using MessageFormat, '{0}' is replaced with the first parameter."
§Retrieving supported language from an HTTP request
You can retrieve the languages supported by a specific HTTP request:
def index = Action { request =>
Ok("Languages: " + request.acceptLanguages.map(_.code).mkString(", "))
}
Next: Testing your application