check if Rails exists for the rails support

lib/couchrest/support/rails.rb

@@ -1,19 +1,17 @@
 # This file contains various hacks for Rails compatibility.
-# To use, just require in environment.rb, like so:
-#
-#   require 'couchrest/support/rails'
 
-class Hash
+if defined?(Rails)
+
+  class Hash
     # Hack so that CouchRest::Document, which descends from Hash,
     # doesn't appear to Rails routing as a Hash of options
     def self.===(other)
       return false if self == Hash && other.is_a?(CouchRest::Document)
       super
     end
-end
+  end
 
-
+  CouchRest::Document.class_eval do
-CouchRest::Document.class_eval do
     # Need this when passing doc to a resourceful route
     alias_method :to_param, :id
   
@@ -29,9 +27,9 @@ CouchRest::Document.class_eval do
     def logger
       ActiveRecord::Base.logger
     end
-end
+  end
 
-CouchRest::CastedModel.class_eval do
+  CouchRest::CastedModel.class_eval do
     # The to_param method is needed for rails to generate resourceful routes.
     # In your controller, remember that it's actually the id of the document.
     def id
@@ -39,14 +37,16 @@ CouchRest::CastedModel.class_eval do
       base_doc.id
     end
     alias_method :to_param, :id
-end
+  end
 
-require Pathname.new(File.dirname(__FILE__)).join('..', 'validation', 'validation_errors')
+  require Pathname.new(File.dirname(__FILE__)).join('..', 'validation', 'validation_errors')
 
-CouchRest::Validation::ValidationErrors.class_eval do
+  CouchRest::Validation::ValidationErrors.class_eval do
     # Returns the total number of errors added. Two errors added to the same attribute will be counted as such.
     # This method is called by error_messages_for
     def count
       errors.values.inject(0) { |error_count, errors_for_attribute| error_count + errors_for_attribute.size }
     end
+  end
+
 end