LocalizedRecord
==============

This plugin gives ActiveRecord objects the ability to have localized attributes.  This is similar to what the
Globalize2 plugin does, however, LocalizedRecord doesn't require any modifications to the database.
It utilizes a simple String column in the DB, and determines if this value is meant to be localized or not based
on the mode that the plugin is set to.

Install
-------

Install this plugin, by running this from your Rails application's root directory:

  script/plugin install git://github.com/glennpow/localized_record.git


Setup
-----

First you can set the global default mode and available locales in an initializer as follows:

  LocalizedRecord.mode = :tsv
  LocalizedRecord.available_locales = [ 'en', 'es' ]

You may also include humanized display names for the available locales:

  LocalizedRecord.available_locales = { 'en' => I18n.t('locales.en'), 'es' => "Español" ]

Then, to add the functionality to an ActiveRecord model, add a line in the class similar this:

  class Message < ActiveRecord::Base
    has_localized :name, :description
  end

The method takes a list of attribute names which it will operate on for this model class.  Alternatively, without
any attribute names, the method will search for all 'string' and 'text' columns, and operate on those.

You can also specify a mode specifically for this ActiveRecord model class:

  has_localized :name, :description, :mode => :tsv


Usage
-----

Now, any time you access any of those attributes of a model of that class, it will check if the value is a localized
String, then look at the current locale (I18n.locale, I18n.default_locale, or user-specified), and then return
the proper translation.

So if a model has 2 translations for it's name, one for English and one for German, and the current I18n.locale is set
to 'de', then calling:

  Message.first.name

Will return:

  "Hallo und Wilkommen"

Or calling:

  Message.first.name(:locale => 'en')

Will return:

  "Hello and Welcome"
  

Template Usage
--------------

There is also an ERB helper which will create text fields or text areas for your localized attributes.
You can add them by first adding a localization select drop down (which when changed, will hide/show the fields
for the selected locale):

  <%= localization_select(f) %>

Where 'f' is either a FormBuilder object or an ActiveRecord object.
And then adding:

  <%= localized_text_field(f, :name) %>
  <%= localized_text_area(f, :description) %>
  
This will create all the fields you need to enter values for these attributes in each of the available_locales.
Note, that when passing options to the text_field or text_area calls (inside the above calls), you may pass a
Proc value which takes 2 parameters to indicate the locale.  Then when iterating through the locales to create
multiple text_fields or areas, these Procs will be called.  The first param is the language code ('en') and the
second param is the humanized name which was set in available_locales (shown above).  Here's an example:

  <%= localized_text_field(f, :name, :class => Proc.new { |locale, locale_name| "locale-field-#{locale}" }) %>

  
Notes on Implementation
-----------------------

I attempted to build the plugin to be compatible with the I18n functionality now found in Rails.  I also originally
envisioned the plugin to have custom "backends" in the same manner as the I18n.  However, I have since postponed/scrapped
this idea in light of the fact that some DB tables may want to use different modes, so one single backend shouldn't
necessarily be set for an application.

The present "backend" does have different modes, which can and will be enhanced as time goes on.  Currently, the only fully
supported mode is :tsv (Tab-separated values).  This mode will put translations into the string column of a record as follows:

"en\tHello and Welcome\tde\tHallo und Wilkommen"

Where the "\t" are tab characters, and the format is locale, value, locale, value,...

The backend can also intelligently check if the current value in the column should be handled as a translation using
the 'localized?' method.  For the :tsv mode, this check simply looks if there are any tabs in the String.
If there is a non-tabbed String in this column, then this value is treated like any other non-localized String
column value in Rails.


Development Note
----------------

Please note that this plugin is very new, and still under development.  But any feedback will be greatly appreciated.
Thanks.


Copyright (c) 2009 Glenn Powell, released under the MIT license