how do i initialize the money gem?

Question

I have a new gem I'm playing with, but I'm not sure where to put it so that it is initialized, but that I don't have to do it each and every time I use my method which uses it.

  def self.get_rate(from, to, amount)
    Money.default_bank.fetch_rates   #<---------------- Here it is...

    if to == "USD" or from == "USD"
      rate = Money.default_bank.get_rate(from, to) * amount
    else
      rate_to_us = Money.default_bank.get_rate(from, "USD") * amount
      rate = Money.default_bank.get_rate("USD", to) * rate_to_us
      #rate = Money.default_bank.get_rate(params[:currency][:from], "USD")
    end
    rate = Money.new(rate.to_money,to).format(:with_currency)
  end

I have to initialize it once otherwise it won't work, but if I do it as it is now, it loads an xml file and whatever else. How can I do it so that it only loads once per day?

Answer 1

Put that logic into application.rb along with a check for the date and time. When the day changes, restart the initialization to update the exchange rates.

Answer 2

The Money gem already supports fetching the exchange rate every so many seconds. You can put the code to set the auto-fetch in your require.rb file (RAILS_ROOT/config/initializers).

Money.default_bank.auto_fetch 86400

From the Money docs:

  Money.default_bank.fetch_rates          # Fetch the rates
  Money.default_bank.auto_fetch 3600      # Fetch the rates every hour
  Money.default_bank.stop_fetch           # Stop auto-fetch