gettext

gettext for Ruby

NOTE: Gettext gem 3.0.0 removed many deprecated APIs and improves internal APIs. We want to keep backward compatibility as much as possible but some existing codes may be broken by gettext gem API change. If your code breaks by gettext gem 3.0.0, please report your problem. We will fix the problem and release a new version.

https://github.com/ruby-gettext/gettext is the official gettext gem repository. It is moved from https://github.com/mutoh/gettext . Mutoh agreed with the move.

Gettext gem is a pure Ruby Localization(L10n) library and tool which is modeled after the GNU gettext package.

This library was called as "Ruby-GetText-Package". Since 2.3.0, this library is called just "gettext". You can call this library as "gettext gem" or "Ruby gettext" to distinguish from GNU gettext.

This library translates original messages to localized messages using client-side locale information(environment variable or CGI variable).

The tools for developers support creating, useing, and modifying localized message files(message catalogs).

Rails support has been removed.

Table of Contents

• Features
• Requirements
• Installation
• Usage
  • Translation
  • _()
  • n_()
  • p_()
  • s_()
  • Combinations
  • N_(), Nn_()
  • Bind textdomains to the classes
  • Locale
• License
• Translators
• Maintainer
• Links

Features

• Translate singular/plural messages with simple APIs (similar to GNU gettext)
• Thread safety. Message resources are shared from all threads, but returns translated messages of the current thread's locale.
• Tools to find message IDs
  • Extract message IDs to po-files using rxgettext from
  • ruby scripts
  • glade-2 XML file (.glade)
  • ERB file (.rhtml, .erb)
  • Anything (with your own parsers)
  • The po-files are compatible with GNU gettext.
  • rmsgfmt creates a mo-file from a po-file. The mo-file is compatible with GNU gettext (msgfmt).
  • Using rxgettext/rmsgfmt as Rake tasks
• textdomain's scope is adapt to ruby class/module mechanism.
  • A class/module can have plural textdomains.
  • a message is looked up in its class/module and ancestors.
• CGI support (gettext/cgi)
  • Locale is retrieved from client informations using Ruby-Locale. (HTTP_ACCEPT_LANGUAGE, HTTP_ACCEPT_CHARSET, QUERY_STRING (lang), Cookies (lang)).

Requirements

• Ruby 1.9.3 or later
• RubyGems
• locale gem

  gem install locale

For development:

• Racc 1.4.3 or later (for compiling src/rmsgfmt.ry only)

Installation

Uninstall old gettext if exists. (You need to do this when updating 1.93.0 -> 2.0.1)

# sudo/su on POSIX system
gem uninstall gettext

RubyGems

# sudo/su on POSIX system
gem install gettext

Download tar-ball

# De-Compress archive and enter its top directory.
# sudo/su on POSIX system
ruby setup.rb

You can also install files in your favorite directory by supplying setup.rb some options. Try ruby setup.rb --help.

Usage

Translation

_() or gettext(): basic translation method

Translates the message, using the msgid if a translation is not found.

_("Hello") => "Bonjour"  # Found

This translation will appear in the po or pot file as:

msgid: "Hello"
msgstr: "Bonjour"

When a translation is not found it, it will return the msgid. This is a core benefit of gettext and applies to all its translation methods.

_("Hello") => "Hello"  # Not Found

Additional gettext methods come in 3 combinable flavors:

n_() or ngettext(): pluralized

Returns singular or plural form, depending on how many you have.

n_("Apple", "%{num} Apples", n) => "3 Pommes"  # When n = 3
n_("Apple", "%{num} Apple", n)  => "Pomme"     # When n = 1
n_(["Apple", "%{num} Apple"], n)  => "Pomme"   # 2 arg variation

This translation will appear in the po or pot file as:

msgid "Apple"
msgid_plural "%{num} Apples"
msgstr[0] "Pomme"
msgstr[1] "#{num} Pommes"

p_() or pgettext(): context aware

A context is a prefix to your translation, useful when one word has different meanings, depending on its context.

p_("Printer","Open") => "Öffnen" #translation found
p_("Printer","Open") => "Open"   #translation not found

This translation will appear in the po or pot file as:

msgctxt "Printer"
msgid "Open"
msgstr "Öffnen"

Note that the parser when sorting by msgid will strictly sort by the msgid ignoring the msgctxt. If you prefer to sort with the msgctxt you should consider the s_() method.

s_() or sgettext(): without context

The s_() method is very similar to the p_() method except that the context is inside the msgid.

s_("Printer|Open") => "Öffnen" #translation found
s_("Printer|Open") => "Open"   #translation not found

msgid "Printer|Open"
msgstr "Öffnen"

Note the the parser when sorting by msgid will take the context into consideration as it is part of the msgid unlike the p_() method.

Your preference of using s_() or p_() will depend on your translation workflow and process.

Combinations

You can combine n_() with either p_() or s_().

np_() or npgettext(): context aware pluralized

np_("Fruit", "Apple", "%{num} Apples", 3)
np_(["Fruit","Apple","%{num} Apples"], 3) # 2 arg variation

msgctxt "Fruit"
msgid "Apple"
msgid_plural "%{num} Apples"
msgstr[0] ""
msgstr[1] ""

sp_() or spgettext(): context aware pluralized

ns_("Fruit|Apple","%{num} Apples", 3)
ns_(["Fruit|Apple","%{num} Apples"], 3) # 2 arg variation

msgid "Fruit|Apple"
msgid_plural "%{num} Apples"
msgstr[0] ""
msgstr[1] ""

N_() and Nn_(): makes dynamic translation messages readable for the gettext parser

_(fruit) cannot be understood by the gettext parser. To help the parser find all your translations, you can add fruit = N_("Apple") which does not translate, but tells the parser: "Apple" needs translation.

fruit = N_("Apple")   # same as fruit = "Apple"
_(fruit)              # does a normal translation

fruits = Nn_("Apple", "%{num} Apples")
n_(fruits, 3)

Interpolating translations

This is not a feature of gettext but worth noting. You can interpolate translated strings with the ruby String % operator.

N_("active"); N_("inactive"); N_("paused") # possible value of status for parser to find.
_("Your account is %{account_state}.") % { account_state: _(status) }

Bind textdomains to the classes

A textdomain has a translation file in each language. A module/class can have multiple textdomains. This means the libraries/applications can have their own textdomains.

class Foo
  include GetText
  bindtextdomain "your_app_domain_name"
end

class Book
  include GetText
  bindtextdomain "general"
  bindtextdomain "book"
end

Locale

If you need to set the locale by yourself, then use:

GetText.locale = "en_US" # translate into english from now on
GetText.locale # => en_US

Or

include GetText
set_locale "en_US"

For more details and options, have a look at the samples folder.

License

This program is licenced under the same licence as Ruby (See doc/text/ruby-license.txt) or LGPL (Lesser General Public License: doc/text/lgpl-3.0.txt or http://www.gnu.org/licenses/lgpl-3.0.txt).

mofile.rb

Copyright (C) 2001-2009 Masao Mutoh <mutoh at highwhay.ne.jp>
Copyright (C) 2001,2002 Masahiro Sakai <s01397ms at sfc.keio.ac.jp>

gettext.rb

Copyright (C) 2001-2009 Masao Mutoh <mutoh at highwhay.ne.jp>
Copyright (C) 2001,2002 Masahiro Sakai <s01397ms at sfc.keio.ac.jp>

rxgettext

Copyright (C) 2001-2009 Masao Mutoh <mutoh at highwhay.ne.jp>
Copyright (C) 2001,2002 Yasushi Shoji <yashi at atmark-techno.com>

Others

Copyright (C) 2001-2009 Masao Mutoh <mutoh at highwhay.ne.jp>

Translators

Maintainer

• Kouhei Sutou <kou@clear-code.com>

Old maintainer

• Masao Mutoh <mutomasa at gmail.com>

Links

• Homepage
• GitHub