Ruby currency exchange gems that work?

问题:

This is based on an earlier question that was resolved. I need to load sale prices for my ruby-based app in different currencies. I was recently using the gem google_currency to convert the prices based on the Google API. At some point recently it stopped working and I have no idea why. I have tried testing in various ways but can't work out what the problem is.

I am now trying to use the 'exchange' gem which has good documentation however the method I am using is not producing anything in the view files when running.

According to the exchange gem the simple conversion should be something like:

def exchange4
   puts 10.in(:eur).to(:usd)

end

However it is not loading anything in the html view. Any suggestions including other working gems welcome!

---

Currently this code seems like it would pass however now Action Controller is telling me it doesn't know the conversion rates:

def exchange4(goods)
    require 'money'
    require 'money-rails'

   exr = Money.new(1, goods.currency).exchange_to(buyer.currency)
    puts exr
end

The error Action Controller is giving is:

No conversion rate known for 'GBP' -> 'EUR'

Very strange..

回答1:

RubyMoney organization has a very good options to deal with currencies, money and exchange. I use money and it really works. For Rails integration they have money-rails.

Examples of exchange:

• Money.us_dollar(100).exchange_to('EUR')

• Money.new(100, 'USD').exchange_to('EUR')

You can use eu_central_bank gem (compatible with money) to extract all exchange rates. Example usage (in rails console):

>> bank = EuCentralBank.new
>> bank.update_rates # if bank.last_updated.blank? || bank.last_updated < 1.day.ago
>> Money.default_bank = bank    

Then:

>> Money.new(1, 'GBP').exchange_to('EUR')
=> #<Money fractional:1 currency:EUR>