Scaposer is a GNU gettext po file parser written in Scala. It's strange that there's not many JVM libraries of this kind, see the discussion on Stackoverflow.

To extract i18n strings from Scala source code files, use Scala xgettext.

Presentation: I18nize Scala programs à la gettext

Discussion group: https://groups.google.com/group/scala-xgettext

Basic usage

See Scaladoc.

val po = """
msgid "Hello"
msgstr "Bonjour"
"""

val result = scaposer.Parser.parse(po)
// => An Either,
// Left(scaposer.ParseFailure) or
// Right(Seq[scaposer.Translation])

Use t methods to get the translations:

val translations = result.right.get
val i18n         = scaposer.I18n(translations)
i18n.t("Hello")  // => "Bonjour"

If there's no translation, or the translation is an empty string (not translated yet), the original input is returned:

i18n.t("Hi")  // => "Hi"

Context

val po = """
msgid "Hello"
msgstr "Bonjour"

msgctxt "Casual"
msgid "Hello"
msgstr "Salut"
"""

val translations = scaposer.Parser.parse(po).right.get
val i18n         = scaposer.I18n(translations)
i18n.tc("Casual", "Hello")  // => "Salut"

If there's no translation for the context, the translation without context is tried:

i18n.tc("Missing context", "Hello")  // => "Bonjour"

Plural-Forms

val po = """
msgid ""
msgstr "Plural-Forms: nplurals=2; plural=n>1;"

msgid "I have one apple"
msgid_plural "I have %d apples"
msgstr[0] "J'ai une pomme"
msgstr[1] "J'ai %d pommes"
"""

val translations = scaposer.Parser.parse(po).right.get
val i18n         = scaposer.I18n(translations)
i18n.tn("I have one apple", "I have %d apples", 1)                // => "J'ai une pomme"
i18n.tn("I have one apple", "I have %d apples", 2)                // => "J'ai %d pommes"
i18n.tcn("A context", "I have one apple", "I have %d apples", 3)  // => "J'ai %d pommes"

For performance, your po file should define Plural-Forms exactly as at:

• http://www.gnu.org/software/gettext/manual/html_node/Plural-forms.html#Plural-forms
• http://www.gnu.org/software/gettext/manual/html_node/Translating-plural-forms.html#Translating-plural-forms

Otherwise, Scaposer cannot compare the plural form string, and it needs to parse and evaluate (slower).

Merge Po objects

You can merge multiple ``I18n``s together.

val i18n4 = i18n1 ++ i18n2 ++ i18n3

Just like when you merge maps, translations in i18n3 will overwrite those in i18n2 will overwrite those in i18n1.

Use with SBT

Supported Scala versions: 2.11-2.13

build.sbt example:

libraryDependencies += "tv.cntt" %% "scaposer" % "1.11.1"

Scaposer is used in Xitrum web framework.