Configurations changed to provide a DSL (similar to Rails) to configure...

Configurations changed to provide a DSL (similar to Rails) to configure Geocoder. A singleton pattern was used to allow the code *Geocoder.configure { |config| ... }*, and delegation was used to maintain compatibility. New configuration options (units and method) for calculations were implemented, with default value: km and spherical, respectively.

lib/geocoder/configuration.rb

+require 'singleton'
+
 module Geocoder
   class Configuration
-
-    def self.options_and_defaults
-      [
-        # geocoding service timeout (secs)
-        [:timeout, 3],
-
-        # name of geocoding service (symbol)
-        [:lookup, :google],
-
-        # ISO-639 language code
-        [:language, :en],
-
-        # use HTTPS for lookup requests? (if supported)
-        [:use_https, false],
-
-        # HTTP proxy server (user:pass@host:port)
-        [:http_proxy, nil],
-
-        # HTTPS proxy server (user:pass@host:port)
-        [:https_proxy, nil],
-
-        # API key for geocoding service
-        [:api_key, nil],
-
-        # cache object (must respond to #[], #[]=, and #keys)
-        [:cache, nil],
-
-        # prefix (string) to use for all cache keys
-        [:cache_prefix, "geocoder:"],
-
-        # exceptions that should not be rescued by default
-        # (if you want to implement custom error handling);
-        # supports SocketError and TimeoutError
-        [:always_raise, []]
-      ]
+    include Singleton
+
+    CONFIGURABLE = [:timeout     , :lookup    , :language    ,
+                    :use_https   , :http_proxy, :https_proxy ,
+                    :api_key     , :cache     , :cache_prefix,
+                    :always_raise, :units     , :method      ]
+
+    attr_accessor *CONFIGURABLE
+
+    def initialize
+      @timeout      = 3           # geocoding service timeout (secs)
+      @lookup       = :google     # name of geocoding service (symbol)
+      @language     = :en         # ISO-639 language code
+      @use_https    = false       # use HTTPS for lookup requests? (if supported)
+      @http_proxy   = nil         # HTTP proxy server (user:pass@host:port)
+      @https_proxy  = nil         # HTTPS proxy server (user:pass@host:port)
+      @api_key      = nil         # API key for geocoding service
+      @cache        = nil         # cache object (must respond to #[], #[]=, and #keys)
+      @cache_prefix = "geocoder:" # prefix (string) to use for all cache keys
+      # exceptions that should not be rescued by default
+      # (if you want to implement custom error handling);
+      # supports SocketError and TimeoutError
+      @always_raise = []
+
+      # Calculation options
+      @units  = :km        # Internationl System standard unit for distance
+      @method = :spherical # More precise
     end
 
-    # define getters and setters for all configuration settings
-    self.options_and_defaults.each do |o,d|
-      eval("def self.#{o}; @@#{o}; end")
-      eval("def self.#{o}=(obj); @@#{o} = obj; end")
-    end
+    # delegates getters and setters for all configuration settings to the instance
+    instance_eval(CONFIGURABLE.map do |method|
+      meth = method.to_s
+      <<-EOS
+      def #{meth}
+        instance.#{meth}
+      end
 
-    ##
-    # Set all values to default.
-    #
-    def self.set_defaults
-      self.options_and_defaults.each do |o,d|
-        self.send("#{o}=", d)
+      def #{meth}=(value)
+        instance.#{meth} = value
       end
-    end
+      EOS
+    end.join("\n\n"))
   end
 end
 
-Geocoder::Configuration.set_defaults