Made association extensions use simpler block syntax

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2895 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -34,14 +34,14 @@
 * Added extension capabilities to has_many and has_and_belongs_to_many proxies [DHH]. Example:
 
     class Account < ActiveRecord::Base
-      has_many :people, :extend => Module.new {
+      has_many :people do
         def find_or_create_by_name(name)
           first_name, *last_name = name.split
           last_name = last_name.join " "
 
           find_or_create_by_first_name_and_last_name(first_name, last_name)
         end
-      }
+      end
     end
 
     person = Account.find(:first).people.find_or_create_by_name("David Heinemeier Hansson")

activerecord/lib/active_record/associations.rb

@@ -127,7 +127,7 @@ module ActiveRecord
     # Example:
     #
     #   class Account < ActiveRecord::Base
-    #     has_many :people, :extend => Module.new {
+    #     has_many :people do
     #       def find_or_create_by_name(name)
     #         first_name, *last_name = name.split
     #         last_name = last_name.join " "
@@ -135,14 +135,32 @@ module ActiveRecord
     #         find_by_first_name_and_last_name(first_name, last_name) ||
     #           create({ :first_name => first_name, :last_name => last_name })
     #       end
-    #     }
+    #     end
     #   end
     #
     #   person = Account.find(:first).people.find_or_create_by_name("David Heinemeier Hansson")
     #   person.first_name # => "David"
     #   person.last_name  # => "Heinemeier Hansson"
     #
-    # Note that the anoymous module must be declared using brackets, not do/end (due to order of evaluation).
+    # If you need to share the same extensions between many associations, you can use a named extension module. Example:
+    #
+    #   module FindOrCreateByNameExtension
+    #     def find_or_create_by_name(name)
+    #       first_name, *last_name = name.split
+    #       last_name = last_name.join " "
+    #     
+    #       find_by_first_name_and_last_name(first_name, last_name) ||
+    #         create({ :first_name => first_name, :last_name => last_name })
+    #     end
+    #   end
+    #
+    #   class Account < ActiveRecord::Base
+    #     has_many :people, :extend => FindOrCreateByNameExtension
+    #   end
+    #
+    #   class Company < ActiveRecord::Base
+    #     has_many :people, :extend => FindOrCreateByNameExtension
+    #   end
     #
     # == Caching
     #
@@ -306,7 +324,7 @@ module ActiveRecord
       #   associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ is _not_ added.
       # * <tt>:counter_sql</tt>  - specify a complete SQL statement to fetch the size of the association. If +:finder_sql+ is
       #   specified but +:counter_sql+, +:counter_sql+ will be generated by replacing SELECT ... FROM with SELECT COUNT(*) FROM.
-      # * <tt>:extend</tt>  - anonymous module for extending the proxy, see "Association extensions".
+      # * <tt>:extend</tt>  - specify a named module for extending the proxy, see "Association extensions".
       #
       # Option examples:
       #   has_many :comments, :order => "posted_on"
@@ -317,13 +335,15 @@ module ActiveRecord
       #       'FROM people p, post_subscriptions ps ' +
       #       'WHERE ps.post_id = #{id} AND ps.person_id = p.id ' +
       #       'ORDER BY p.first_name'
-      def has_many(association_id, options = {})
+      def has_many(association_id, options = {}, &extension)
         options.assert_valid_keys(
           :foreign_key, :class_name, :exclusively_dependent, :dependent, 
           :conditions, :order, :finder_sql, :counter_sql, 
           :before_add, :after_add, :before_remove, :after_remove, :extend
         )
 
+        options[:extend] = create_extension_module(association_id, extension) if block_given?
+
         association_name, association_class_name, association_class_primary_key_name =
               associate_identification(association_id, options[:class_name], options[:foreign_key])
  
@@ -602,13 +622,15 @@ module ActiveRecord
       #   has_and_belongs_to_many :categories, :join_table => "prods_cats"
       #   has_and_belongs_to_many :active_projects, :join_table => 'developers_projects', :delete_sql => 
       #   'DELETE FROM developers_projects WHERE active=1 AND developer_id = #{id} AND project_id = #{record.id}'
-      def has_and_belongs_to_many(association_id, options = {})
+      def has_and_belongs_to_many(association_id, options = {}, &extension)
         options.assert_valid_keys(
           :class_name, :table_name, :foreign_key, :association_foreign_key, :conditions,
           :join_table, :finder_sql, :delete_sql, :insert_sql, :order, :uniq, :before_add, :after_add, 
           :before_remove, :after_remove, :extend
         )
 
+        options[:extend] = create_extension_module(association_id, extension) if block_given?
+
         association_name, association_class_name, association_class_primary_key_name =
               associate_identification(association_id, options[:class_name], options[:foreign_key])
 
@@ -1004,7 +1026,16 @@ module ActiveRecord
         def condition_word(sql)
           sql =~ /where/i ? " AND " : "WHERE "
         end
-    end
 
+        def create_extension_module(association_id, extension)
+          extension_module_name = "#{self.to_s}#{association_id.to_s.camelize}AssociationExtension"
+
+          silence_warnings do
+            Object.const_set(extension_module_name, Module.new(&extension))
+          end
+          
+          extension_module_name.constantize
+        end
+    end
   end
 end

activerecord/lib/active_record/reflection.rb

@@ -22,8 +22,8 @@ module ActiveRecord
           class << self
             alias_method :#{association_type}_without_reflection, :#{association_type}
       
-            def #{association_type}_with_reflection(association_id, options = {})
-              #{association_type}_without_reflection(association_id, options)
+            def #{association_type}_with_reflection(association_id, options = {}, &block)
+              #{association_type}_without_reflection(association_id, options, &block)      
               reflect_on_all_associations << AssociationReflection.new(:#{association_type}, association_id, options, self)
             end
       

activerecord/test/associations_extensions_test.rb

@@ -7,11 +7,31 @@ require 'fixtures/developer'
 class AssociationsExtensionsTest < Test::Unit::TestCase
   fixtures :projects, :developers, :comments, :posts
 
+  def test_extension_on_has_many
+    assert_equal comments(:more_greetings), posts(:welcome).comments.find_most_recent
+  end
+  
   def test_extension_on_habtm
     assert_equal projects(:action_controller), developers(:david).projects.find_most_recent
   end
 
-  def test_extension_on_has_many
-    assert_equal comments(:more_greetings), posts(:welcome).comments.find_most_recent
+  def test_named_extension_on_habtm
+    assert_equal projects(:action_controller), developers(:david).projects_extended_by_name.find_most_recent
+  end
+  
+  def test_marshalling_extensions
+    david = developers(:david)
+    assert_equal projects(:action_controller), david.projects.find_most_recent
+
+    david = Marshal.load(Marshal.dump(david))
+    assert_equal projects(:action_controller), david.projects.find_most_recent
+  end
+
+  def test_marshalling_named_extensions
+    david = developers(:david)
+    assert_equal projects(:action_controller), david.projects_extended_by_name.find_most_recent
+
+    david = Marshal.load(Marshal.dump(david))
+    assert_equal projects(:action_controller), david.projects_extended_by_name.find_most_recent
   end
 end

activerecord/test/fixtures/developer.rb

@@ -1,10 +1,21 @@
+module DeveloperProjectsAssociationExtension
+  def find_most_recent
+    find(:first, :order => "id DESC")
+  end
+end
+
 class Developer < ActiveRecord::Base
-  has_and_belongs_to_many :projects, :extend => Module.new {
+  has_and_belongs_to_many :projects do
     def find_most_recent
       find(:first, :order => "id DESC")
     end
-  }
+  end
   
+  has_and_belongs_to_many :projects_extended_by_name, 
+      :class_name => "Project", 
+      :join_table => "developers_projects", 
+      :association_foreign_key => "project_id",
+      :extend => DeveloperProjectsAssociationExtension
 
   has_and_belongs_to_many :special_projects, :join_table => 'developers_projects', :association_foreign_key => 'project_id'
 

activerecord/test/fixtures/post.rb

@@ -1,15 +1,15 @@
 class Post < ActiveRecord::Base
-  belongs_to :author, :extend => Module.new {
+  belongs_to :author do
     def greeting
       "hello"
     end
-  }
+  end
 
-  has_many   :comments, :order => "body", :extend => Module.new {
+  has_many   :comments, :order => "body" do
     def find_most_recent
       find(:first, :order => "id DESC")
     end
-  }
+  end
 
   has_one  :very_special_comment
   has_many :special_comments