@@ -7,6 +7,34 @@ h2. Requirements and Installation * Install the hpricot gem (gem install hpricot) * Install the cash_handler plugin (script/plugin install git://github.com/JamesBrooks/cash_handler.git) +h2. Usage + +<pre><code> + c = CashHandler::Base.new + + # Get the current exchange rate of the AUD against the USD (currency code strings are case in-sensitive, can also be symbols) + c.get('AUD') + => 0.619099 + + # Get the current exchange rate of the AUD against the GBP + c.get('AUD', :against => 'GBP') + => 0.418621272567449 + + # Convert + c.convert(10, :aud, :usd) + => 6.19099 + + # Force the converstion rates cache to reload currencies + c.cache.expire + + # The CashHandler::Cache has a default cache life of one day, this can be overridden in one of two ways + # Upon creation + c = CashHandler::Base.new(30.minutes) + + # During operation + c.cache.ttl = 30.minutes +</code></pre> + h2. Copyright and License Copyright (c) 2008 James Brooks, released under the MIT license README.textile @@ -2,18 +2,19 @@ module CashHandler class Base attr_accessor :cache - def initialize - @cache = CashHandler::Cache.new + # Init the CashHandler (and cache), with a default TTL of 1 day + def initialize(ttl=1.day) + @cache = CashHandler::Cache.new(ttl) end # Fetches the exchange rate of a currency against the USD - def get(code) - @cache.get(code.to_s.upcase) + def get(code, options={:against => :usd}) + @cache.get(code.to_s.upcase) / @cache.get(options[:against].to_s.upcase) end # Converts a value from one currency to another def convert(value, from, to) - value * get(from) / get(to) + value * get(from, :against => to) end end end lib/cash_handler/base.rb @@ -5,15 +5,15 @@ module CashHandler attr_accessor :ttl # Creates the cache with a default TTL (time to live) of 1 day. After this TTL has elapsed, cached values are refreshed - def initialize(ttl=1.day) + def initialize(ttl) @ttl = ttl @expires_at = ttl.from_now - expire_cache + expire end # Forces an expiry of the cache - def expire_cache + def expire @expires_at = ttl.from_now @rates = CashHandler::Parser.fetch_rates end @@ -21,7 +21,7 @@ module CashHandler # Fetches a cached values (and refreshes the cache if it has expired) def get(code) # Ensure we have a collection of rates - expire_cache unless @rates && @rates.any? && @expires_at > Time.now + expire unless @rates && @rates.any? && @expires_at > Time.now if @rates[code] @rates[code] lib/cash_handler/cache.rb b1186d15f91552648e4ddcf3451164a0f1e78f0e James Brooks james@gooddogdesign.com http://github.com/JamesBrooks/cash_handler/commit/5c65f27e79b4d18130f65556e3c4d78936ca9448 5c65f27e79b4d18130f65556e3c4d78936ca9448 2008-11-20T16:29:55-08:00 2008-11-20T16:29:55-08:00 Added fetching exchange rates as values against rates other than the USD. Made changing the cache TTL easier (during creation) 7cd5ce2fa64abe96b4c542fb6745948b2654d86b James Brooks james@gooddogdesign.com