handle subdomain based accounts in rails

subdomain_accounts.rb

# 
# Inspired by 
#   http://dev.rubyonrails.org/svn/rails/plugins/account_location/lib/account_location.rb
# 
module SubdomainAccounts
  def self.included( controller )
    controller.helper_method(:account_domain, :account_subdomain, :account_url, :current_account, :default_account_subdomain, :default_account_url)
  end
  
  protected
    
    # TODO: need to handle www as well
    def default_account_subdomain
      ''
    end
    
    def account_url( account_subdomain = default_account_subdomain, use_ssl = request.ssl? )
      http_protocol(use_ssl) + account_host(account_subdomain)
    end
    
    def account_host( subdomain )
      account_host = ''
      account_host << subdomain + '.'
      account_host << account_domain
    end

    def account_domain
      account_domain = ''
      account_domain << request.domain + request.port_string
    end

    def account_subdomain
      request.subdomains.first || ''
    end
    
    def default_account_url( use_ssl = request.ssl? )
      http_protocol(use_ssl) + account_domain
    end      
          
    def current_account
      Account.find_by_subdomain(account_subdomain)
    end
    
    def http_protocol( use_ssl = request.ssl? )
      (use_ssl ? "https://" : "http://")
    end 
end