I18nTemplate

Main Feature

Just compare regulare rails view internationalization:

<html>
  <body>
    <% current_year = Time.now.year %>
    <span><%= t('hello') %></span>
    <h2><%= t('Dashboard') </h2>
    <div><%= t('Posts count:') %><%= current_user.posts.count %></div>
    <div><%= t('Click') %><a href="#"><%= t('here') %></a></div>
    ...
  </body>
</html>

with i18n template internationalization:

<html>
  <body>
    <% current_year = Time.now.year %>
    <span i18n="p">hello</span>
    <h2>Dashboard</h2>
    <div>Posts count: <%= current_user.posts.count %></div>
    <div>Click<a href="#">here</a></div>
    ...
  </body>
</html>

Nice?

How it Works

It convert on the fly regular erb template to another erb template. For above example this is something like:

<html>
  <body>
    <% current_year = Time.now.year %>
    <span>
      <%- i18n_variables = {}; i18n_wrappers = [] -%>
      <%= ::I18nTemplate::Translation.translate("hello", i18n_wrappers, i18n_variables) %>
    </span>
    <h2>
      <%- i18n_variables = {}; i18n_wrappers = [] -%>
      <%= ::I18nTemplate::Translation.translate("Dashboard", i18n_wrappers, i18n_variables) %>
     </h2>
    <div>
      <%- i18n_variables = {}; i18n_wrappers = [] -%>
      <%- i18n_variables['current user posts count'] = capture do -%>
        <%= current_user.posts.count %>
      <%- end -%>
      <%= ::I18nTemplate::Translation.translate("Posts count: {current user posts count}",
          i18n_wrappers, i18n_variables) %>
    </div>
    <div>
      <%- i18n_variables = {}; i18n_wrappers = [] -%>
      <%- i18n_wrappers[1] = capture do -%>
        <a href="#" i18n_wrapper="1">
          <%- i18n_variables = {}; i18n_wrappers = [] -%>
          <%= ::I18nTemplate::Translation.translate("here", i18n_wrappers, i18n_variables) %>
        </a>
      <%- end -%>
      <%= ::I18nTemplate::Translation.translate("Click[1]here[/1]", i18n_wrappers, i18n_variables) %>
     </div>
  </body>
</html>

Translation phrases (keys):

Description

I18nTemplate is made to extract phrases and translate html/xhtml/xml document or erb templates. Currently the it can work with (x)html documents. Translation is done by modify the original template (on the fly) to be translated on erb execution time.

Semantics

The engine is leveraging the HTML document semantics. As we know HTML document element can contain : block elements and/or inline elements. The engine has the following parsing rules, based on what kind of children a parent element contains:

Markup

Additionally for the sake of best practices and optimiztion the following rules take place:

In order to fix a broken elements next elements/attributes can be added to the html document to resolve engine misunderstanding:

Translation

Brackets

[1]Hello World[/1]

Braces

Example

Hello { user name }

Using with Rails (2.3.x 3.x.x)

$ gem install i18n_template

require 'i18n_template'

ActionView::Template.register_template_handler(:erb, I18nTemplate::Handler.new)

Set another phrase translator:

I18nTemplate.phrase_translator = lambda { |phrase| Google.translate(phrase) }

More template internationalize control

Assume we don't want to internationalize admin view templates.

class MyI18nTemplateHandler < I18nTemplate::Handler
  def internationalize?(template)
    if template.respond_to?(:path)
      path =~ /^admin/ ? false : true
    else
      true
    end
  end
end

ActionView::Template.register_template_handler(:erb, MyI18nTemplateHandler.new)

Testing

Setup

$ rvm alias create rails23_r187 ruby-1.8.7
$ rvm alias create rails30_r193 ruby-1.9.3
$ rvm alias create rails31_r193 ruby-1.9.3

$ gem install multiversion
$ multiversion all bundle install

Run

Against all versions:

$ multiversion all exec testrb test/*_test.rb

Against specific versions:

$ multiversion rails30_r193,rails31_r193 exec testrb test/*_test.rb

Extract phrases

$ i18n_template --help
extract_phrases - extract phrases for translations
    --format plain|gettext|yaml  translation format (default gettext)
    --po-root PO ROOT            root directly for po files (default po)
    --glob GLOB                  template files glob (default app/views/**/*.{erb,rhtml})
    --textdomain TEXTDOMAIN      gettext textdomain (default phrases)
    --output-file FILE           output file (default template_phrases.txt)
    --locales-root DIRECTORY     locales directory (default config/locales)

Plain format

$ i18n_template extract_phrases --format plain --output-file /tmp/phrases.txt

Yaml format

$ i18n_template extract_phrases --format yaml

$ cat config/locales/phrases.yml
en:
  Hello {user name}, {message}: 
  '[1]First name[/1] : {profile first name}': 
  '[1]Last name[/1] : {profile last name}': 
  '[1]Email[/1] : {account email}': 
  Copyright {current year}. All rights reserved.:

Gettext format

$ i18n_template extract_phrases \
  --textdomain myapp \
  --glob app/views/**/*.erb \
  --glob lib/view/**/*.erb

$ tree --dirsfirst po
po
├── de
│   └── myapp.po
└── myapp.pot

$ cat po/phrases.pot
# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
# This file is distributed under the same license as the PACKAGE package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"POT-Creation-Date: 2011-11-28 15:38+0200\n"
"PO-Revision-Date: 2011-11-25 21:27+0200\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"Language: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Plural-Forms: nplurals=INTEGER; plural=EXPRESSION;\n"

# app/views/_footer.html.erb
msgid "Copyright {current year}. All rights reserved."
msgstr ""

# app/views/greeting.html.erb
msgid "Hello {user name}, {message}"
msgstr ""

References