3 files changed, 29 insertions, 3 deletions
diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index d89389338c..dcaa5cecd4 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,26 @@
 *SVN*
 
+* Added to_param call for parameters when composing an url using url_for from something else than strings #812 [Sam Stephenson]. Example:
+
+    class Page
+      def initialize(number)
+        @number = number
+      end
+      # ...
+      def to_param
+        @number.to_s
+      end
+    end
+
+  You can now use instances of Page with url_for:
+
+    class BarController < ApplicationController
+      def baz
+        page = Page.new(4)
+        url = url_for :page => page # => "http://foo/bar/baz?page=4"
+      end
+    end
+
 * Fixed form helpers to query Model#id_before_type_cast instead of Model#id as a temporary workaround for Ruby 1.8.2 warnings #818 [DeLynn B]
 
 * Fixed TextHelper#markdown to use blank? instead of empty? so it can deal with nil strings passed #814 [Johan Sörensen]
diff --git a/actionpack/lib/action_controller/routing.rb b/actionpack/lib/action_controller/routing.rb
index c021d88ca9..20bc6c8cae 100644
--- a/actionpack/lib/action_controller/routing.rb
+++ b/actionpack/lib/action_controller/routing.rb
@@ -64,9 +64,9 @@ module ActionController
       	    if value.nil? || item == :controller
               value
             elsif collection
-	            CGI.escape(value.to_s).gsub(/%2F/, "/")
+	            Routing.extract_parameter_value(value).gsub(/%2F/, "/")
             else
-              CGI.escape(value.to_s)
+              Routing.extract_parameter_value(value)
             end
           else
             item
@@ -316,6 +316,11 @@ module ActionController
       end
     end
     
+    def self.extract_parameter_value(parameter)
+      value = parameter.respond_to?(:to_param) ? parameter.to_param : parameter.to_s
+      CGI.escape(value)
+    end
+
     def self.draw(*args, &block) #:nodoc:
       Routes.draw(*args) {|*args| block.call(*args)}
     end
diff --git a/actionpack/lib/action_controller/url_rewriter.rb b/actionpack/lib/action_controller/url_rewriter.rb
index 6c51ef3f3e..bbfa6009a4 100644
--- a/actionpack/lib/action_controller/url_rewriter.rb
+++ b/actionpack/lib/action_controller/url_rewriter.rb
@@ -95,7 +95,7 @@ module ActionController
           key = CGI.escape key
           key += '[]' if value.class == Array
           value = [ value ] unless value.class == Array
-          value.each { |val| elements << "#{key}=#{CGI.escape(val.to_s)}" }
+          value.each { |val| elements << "#{key}=#{Routing.extract_parameter_value(val)}" }
         end
         
         query_string << ("?" + elements.join("&")) unless elements.empty?