Play Framework 2.4.0 and I18n with Scala - scala

Question

I have a project with Play Framework 2.3.8 and I'm migrating in Play Framework 2.4 but I have a problem with I18n.
Now I have in a view code like this:
#Messages("components.navbar.text")(locale.MyLang)
where locale is:
object locale {
var MyLang =Lang("it")
def changeLang(newLang:String): Unit ={
MyLang=Lang(newLang)
}
}
I would mantainer this structure without using implicit lang, is possible ?
I have some situation where I use in the same page different language and in this case is difficult and boring with the implicit lang.

Answer 1

If I understand your question correctly, which is that you want to override the user's chosen language for certain blocks of the page, I would do this (for Play 2.4) using an implicit Messages object:
#()(implicit messages: Messages)
<!-- some section in the user's chosen language -->
<h1>#Messages("hello.world")</h1>
<!-- some section in a specific language -->
#defining(messages.copy(lang = play.api.i18n.Lang("it")) { implicit messages =>
<h2>#Messages("something.in.italian")</h2>
}
That is, use defining to create a new (implicit) messages for certain nested blocks of HTML.
If you really wanted to go to town (and I wouldn't necessarily recommend this) you could add an italian method to Messages via an implicit class:
(in my.package.utils.i18n.MessagesExtensions.scala):
package my.packages.utils.i18n
import play.api.i18n.{Lang, Messages}
implicit class MessagesExtensions(messages: Messages) {
def italian = messages.copy(lang = Lang("it"))
// and an `as` method for good measure:
def as(code: String) = messages.copy(lang = Lang(code))
}
To have that work in a view you need to add the class to your templateImport in your build.sbt:
templateImports in Compile ++= Seq(
"my.packages.utils.i18n.MessagesExtensions"
)
Then in your templates you can just to this:
#()(implicit messages: Messages)
<!-- some section in the user's chosen language -->
<h1>#Messages("hello.world")</h1>
<!-- some section in a specific language -->
#defining(messages.italian) { implicit messages =>
<h2>#Messages("something.in.italian")</h2>
....
}
<!-- or singly, in another language -->
<h3>#Messages("another.thing.in.french")(messages.as("fr"))</h3>
But that might be overkill, unless it really saves you a lot of boilerplate language switching.