Switching locale

How about switching the locale?

Getting locale option from params.

In the application_controller.rb file:

   class ApplicationController < ActionController::Base
     protect_from_forgery
 
     before_filter :set_locale
 
     def set_locale
       I18n.locale = params[:locale] || I18n.default_locale
     end
   end

Or

def set_locale
  if params[:locale].in? %W(en zh-TW)
    I18n.locale = params[:locale]
  end
end

And now, we can access different with the params query: http://0.0.0.0:3000/?locale=en.

Automatically appending the locale params to URL.

Rails comes with a default_url_options that is the default query string and values that will be attached in the URL.

We can override the default_url_options. Add the following method in the application_controller.rb file.

def default_url_options
  { locale: I18n.locale }
end

This only applies to URL which is generated by rails, such as root_path. Manually typing the URL will not get the default_url_options attached.

And than the UI to switch. Since we want the language available everywhere, put it in the applicotian.html.erb file.

<a href='?locale=zh-TW'>中</a> | <a href='?locale=en'>EN</a>

For more detail, check http://guides.rubyonrails.org/i18n.html. For example, adding locale as part of the URL

What’s next? We’re going to take a look at “Pow local server”.