Add parameter defaults support to new routing DSL [#4265 state:resolved]

Signed-off-by: wycats <wycats@gmail.com>

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -32,6 +32,8 @@ def call(env)
       end
 
       class Mapping
+        IGNORE_OPTIONS = [:to, :as, :controller, :action, :via, :on, :constraints, :defaults, :only, :except, :anchor]
+
         def initialize(set, scope, args)
           @set, @scope    = set, scope
           @path, @options = extract_path_and_options(args)
@@ -96,7 +98,15 @@ def requirements
           end
 
           def defaults
-            @defaults ||= if to.respond_to?(:call)
+            @defaults ||= (@options[:defaults] || {}).tap do |defaults|
+              defaults.merge!(default_controller_and_action)
+              defaults.reverse_merge!(@scope[:defaults]) if @scope[:defaults]
+              @options.each { |k, v| defaults[k] = v unless v.is_a?(Regexp) || IGNORE_OPTIONS.include?(k.to_sym) }
+            end
+          end
+
+          def default_controller_and_action
+            if to.respond_to?(:call)
               { }
             else
               defaults = case to
@@ -299,6 +309,10 @@ def constraints(constraints = {})
           scope(:constraints => constraints) { yield }
         end
 
+        def defaults(defaults = {})
+          scope(:defaults => defaults) { yield }
+        end
+
         def match(*args)
           options = args.extract_options!
 
@@ -343,6 +357,10 @@ def merge_constraints_scope(parent, child)
             merge_options_scope(parent, child)
           end
 
+          def merge_defaults_scope(parent, child)
+            merge_options_scope(parent, child)
+          end
+
           def merge_blocks_scope(parent, child)
             (parent || []) + [child]
           end

actionpack/test/dispatch/routing_test.rb

@@ -121,6 +121,13 @@ def self.matches?(request)
       # misc
       match 'articles/:year/:month/:day/:title', :to => "articles#show", :as => :article
 
+      # default params
+      match 'inline_pages/(:id)', :to => 'pages#show', :id => 'home'
+      match 'default_pages/(:id)', :to => 'pages#show', :defaults => { :id => 'home' }
+      defaults :id => 'home' do
+        match 'scoped_pages/(:id)', :to => 'pages#show'
+      end
+
       namespace :account do
         match 'shorthand'
         match 'description', :to => "account#description", :as => "description"
@@ -769,6 +776,19 @@ def test_nested_optional_scoped_path
     end
   end
 
+  def test_default_params
+    with_test_routes do
+      get '/inline_pages'
+      assert_equal 'home', @request.params[:id]
+
+      get '/default_pages'
+      assert_equal 'home', @request.params[:id]
+
+      get '/scoped_pages'
+      assert_equal 'home', @request.params[:id]
+    end
+  end
+
   private
     def with_test_routes
       yield