Class: RTicker::Currency

Inherits:
Entry
  • Object
show all
Defined in:
lib/rticker/currency.rb

Overview

Represents currency pairs (e.g. USD/EUR)

Instance Attribute Summary

Attributes inherited from Entry

#bold, #curr_value, #description, #last_changed, #purchase_count, #purchase_price, #symbol

Class Method Summary collapse

Methods inherited from Entry

#initialize

Constructor Details

This class inherits a constructor from RTicker::Entry

Class Method Details

.update(entries) ⇒ Object

In the context of currency pairs, each increment in @purchase_count represents single units of the quote currency exchanged for the base currency. (The base currency is the first of the pair, the quote currency is the second.) @purchase_price represents the pair ratio when the purchase was made. For instance, a @purchase_count of 1000 and @purchase_price of 1.412 for the currency pair ‘EUR/USD’ means that $1000 USD was swapped for 708.21 euros. A negative @purchase_count of -1000 would mean that 1000 euros were swapped for $1,412 USD.



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# File 'lib/rticker/currency.rb', line 19

def Currency.update (entries)
  # Strip out anything from symbol that is not an uppercase character
  # This allows the user to freely use USD/EUR or USD.EUR, etc.
  symbols = entries.map { |e| e.symbol.tr("^A-Z", "") }
  uri_param = symbols.map{|x| x+"=X"}.join(",")
  uri = "http://download.finance.yahoo.com/d/quotes.csv?s=%s&f=sl1d1t1ba&e=.csv" % CGI::escape(uri_param)
  response = RTicker::Net.get_response(uri) rescue return
  return if response.empty? or response =~ /"N\/A"/ # Yahoo sometimes returns bogus info.
  results = response.split("\n")
  entries.zip(results) do |entry, result|
    # Yahoo uses A CSV format.
    fields = result.split(",")
    price = fields[1]
    last_date = fields[2]
    return if last_date.nil? or Date.strptime(last_date, '"%m/%d/%Y"') != Date.today
    if price.to_f != entry.curr_value and not entry.curr_value.nil?
      # The price has changed
      entry.last_changed = Time.now() 
    end
    entry.curr_value = price.to_f
    # Currencies aren't regulated.  So no need to calculate the
    # @start_value, because there is no market open.  Currencies trade
    # 24/7
  end
end