g11n

Overview ¶

Package g11n is an internationalization library that offers:

• Statically-typed message keys.
• Parameterized messages.
• Extendable message formatting.
• Custom localization file format.

I. Initialization

Create a new instance of g11n. Each instance handles messages and locales separately.

G = g11n.New()

Define a struct with messages.

type Messages struct {
	TheAnswer func(string, int) string `default:"The answer to %v is %v."`
}

Initialize an instance of the struct through the g11n object.

var M *Messages
G.Init(M)

Invoke messages on that instance.

M.TheAnswer("everything", 42")

II. Choosing locale

Load a locale in the g11n instance.

G.LoadLocale("json", "bg", bgLocalePath)

Different locale loaders could be registered by implementing the locale.Loader interface.

Specify the locale for every message struct initialized by this g11n instance.

G.SetLocale("en")

III. Format parameters

The parameters of a message call could be formatted by declaring a special type that implements

G11nParam() string

The format method G11nParam is invoked before substituting a parameter in the message.

type PluralFormat int

func (pf PluralFormat) G11nParam() string {
	switch pf {
	case 0:
		return "some"
	case 1:
		return "crazy"
	default:
		return "stuff"
	}
}

type M struct {
	MyLittleSomething func(PluralFormat) string `default:"Count: %v"`
}

IV. Format result

The result of a message call could be further formatted by declaring a special result type that implements

G11nResult(formattedMessage string) string

The format method G11nResult is invoked after all parameters have been substituted in the message.

type SafeHTMLFormat string

func (shf SafeHTMLFormat) G11nResult(formattedMessage string) string {
	r := strings.NewReplacer("<", `\<`, ">", `\>`, "/", `\/`)
	return r.Replace(formattedMessage)
}

type M struct {
	MyLittleSomething func() SafeHTMLFormat `default:"<message>Oops!</message>"`
}