Messages

This repository handles message translations using simple JSON files for Go (Golang) projects. The messages can be specific to a language or a combination of language and region.

# Example translation file en.json
{
    "welcome.message": "Welcome :user!"
}

Message extraction

Users can use the msgextractor tool to extract translation keys from your go source files. This will collect every value of type github.com/wvell/messages.Key from the src directory.

msgextractor -dst path_to_translation_files --src path_to_go_source_files

// Use -default-language to set the default language as source for the translations. Missing translations for other languages will use this as the source.
msgextractor -dst path_to_translation_files -src path_to_go_source_files -default-language en

Usage

// Parse translations.
translations, err := messages.FromDir("directory with translation files")
if err != nil {
    // Handle error
    log.Fatalf("Failed to parse translations: %v", err)
}

// Setting the language context per request.
// Parse the language from a user request. This can be from a header or user settings, for example the http Accept-Language header.
ctx := context.Background()
ctx, err := messages.WithLanguage(ctx, r.Header.Get("Accept-Language"))
if err != nil {
    // Handle error...
}
// Translate the message.
// If the user requested "en-US" but you only have "en" translations available, the translator will use the "en" translations.
msg := translations.Translate(ctx, "welcome.message", map[string]any{"user": "wvell"})
fmt.Println(msg) // prints: Welcome wvell!

Capitalization

You can use a capitalized replacement to to capitalize the replacement value:

{
    "welcome.message": "Welcome :User!"
}

This will change the replacement value "john" to "John".

Attributes

Attributes allow you to reuse placeholder values, which is particularly useful for validation messages. The following example illutrates the required validation message. Without attributes you would have to create a translation for each field(required.first_name, required.street).

# es.json
{
  "required": ":Attribute es requerido"
  "attributes": {
    "field" : {
      "first_name": "nombre",
      "street": "calle"
    }
  }
}

tr.Translate(ctx, "required", map[string]any{"attribute": "first_name"}) // Nombre es requerido
tr.Translate(ctx, "required", map[string]any{"attribute": "street"}) // Calle es requerido

As you can see this also takes the title case for the translation message into account.