From b2473c82168c98b7ef3ee794b0cff0b5fb20372c Mon Sep 17 00:00:00 2001
From: Szymon Nowak <szimek@gmail.com>
Date: Mon, 31 May 2010 14:01:18 +0200
Subject: [PATCH] Allow to use procs when specifying defaults for routes.

Example:
scope "/:locale", :defaults => { :locale => Proc.new { I18n.locale } } do
  resources :pages
end

page_path(5) => "/en/pages/5"
page_path(5, :locale => :de) => "/de/pages/5"
---
 actionpack/lib/action_dispatch/routing/route.rb    |   22 ++++++++++++++
 .../lib/action_dispatch/routing/route_set.rb       |   30 ++++++++++++-------
 actionpack/test/dispatch/routing_test.rb           |    8 +++++
 3 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/actionpack/lib/action_dispatch/routing/route.rb b/actionpack/lib/action_dispatch/routing/route.rb
index 6f37ead..829ca4b 100644
--- a/actionpack/lib/action_dispatch/routing/route.rb
+++ b/actionpack/lib/action_dispatch/routing/route.rb
@@ -41,6 +41,28 @@ module ActionDispatch
         @segment_keys ||= conditions[:path_info].names.compact.map { |key| key.to_sym }
       end
 
+      def required_with_default_segment_keys
+        @required_with_default_segment_keys ||= begin
+          required_defaults = @defaults.dup
+          required_defaults.delete(:controller)
+          required_defaults.delete(:action)
+
+          non_optional_segment_keys = path.sub(/\(.+\)/, "").sub(/^\//, "").split("/")
+
+          mark_as_optional = true
+          required_dynamic_segment_keys = []
+          non_optional_segment_keys.reverse_each do |key|
+            is_dynamic = !!(key =~ /^:/)
+            mark_as_optional  &&= is_dynamic
+            if is_dynamic && !mark_as_optional
+              required_dynamic_segment_keys << key[1..-1].to_sym
+            end
+          end
+
+          required_defaults.keys & required_dynamic_segment_keys
+        end
+      end
+
       def to_a
         [@app, @conditions, @defaults, @name]
       end
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 0d071dd..17f20ec 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -139,12 +139,12 @@ module ActionDispatch
             selector = hash_access_name(name, kind)
 
             # We use module_eval to avoid leaks
-            @module.module_eval <<-END_EVAL, __FILE__, __LINE__ + 1
-              def #{selector}(options = nil)                                      # def hash_for_users_url(options = nil)
-                options ? #{options.inspect}.merge(options) : #{options.inspect}  #   options ? {:only_path=>false}.merge(options) : {:only_path=>false}
+            @module.module_eval do
+              define_method(selector) do |*args|                                  # def hash_for_users_url(*args)
+                args.first ? options.merge(args.first) : options                  #   args.first ? {:only_path=>false}.merge(args.first) : {:only_path=>false}
               end                                                                 # end
-              protected :#{selector}                                              # protected :hash_for_users_url
-            END_EVAL
+              protected selector                                                  # protected :hash_for_users_url
+            end
             helpers << selector
           end
 
@@ -165,19 +165,19 @@ module ActionDispatch
             selector = url_helper_name(name, kind)
             hash_access_method = hash_access_name(name, kind)
 
-            @module.module_eval <<-END_EVAL, __FILE__, __LINE__ + 1
-              def #{selector}(*args)
-                options =  #{hash_access_method}(args.extract_options!)
+            @module.module_eval do
+              define_method(selector) do |*args|
+                options =  send(hash_access_method, args.extract_options!)
 
                 if args.any?
                   options[:_positional_args] = args
-                  options[:_positional_keys] = #{route.segment_keys.inspect}
+                  options[:_positional_keys] = route.segment_keys - route.required_with_default_segment_keys
                 end
 
                 url_for(options)
               end
-              protected :#{selector}
-            END_EVAL
+              protected selector
+            end
             helpers << selector
           end
       end
@@ -297,6 +297,7 @@ module ActionDispatch
           use_relative_controller!
           controller.sub!(%r{^/}, '') if controller
           handle_nil_action!
+          evaluate_default_options!
         end
 
         def controller
@@ -366,6 +367,13 @@ module ActionDispatch
           recall[:action] = options.delete(:action) if options[:action] == 'index'
         end
 
+        def evaluate_default_options!
+          @options = options.inject({}) do |h, (k, v)|
+            h[k] = v.is_a?(Proc) ? v.call : v
+            h
+          end
+        end
+
         def generate
           error = ActionController::RoutingError.new("No route matches #{options.inspect}")
           path, params = @set.generate(:path_info, named_route, options, recall, opts)
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index 180889d..b6df369 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -138,6 +138,7 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
       # default params
       match 'inline_pages/(:id)', :to => 'pages#show', :id => 'home'
       match 'default_pages/(:id)', :to => 'pages#show', :defaults => { :id => 'home' }
+      match ':locale/:book/pages/(:id)', :to => 'pages#show', :as => :page, :defaults => { :locale => Proc.new { I18n.locale }, :id => 'home' }
       defaults :id => 'home' do
         match 'scoped_pages/(:id)', :to => 'pages#show'
       end
@@ -957,6 +958,13 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
 
       get '/scoped_pages'
       assert_equal 'home', @request.params[:id]
+
+      get '/en/catch-22/pages'
+      assert_equal 'en',   @request.params[:locale]
+      assert_equal 'home', @request.params[:id]
+
+      assert_equal '/en/catch-22/pages', page_path("catch-22")
+      assert_equal '/de/catch-22/pages', page_path("catch-22", :locale => :de)
     end
   end
 
-- 
1.7.1