Sync with rails/rails/master, merge two metaprogramming annotation efforts

11 files changed, 188 insertions, 69 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 9cfd16cc0d..c750f486f9 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *2.3.0/3.0*
 
+* Added dynamic scopes ala dynamic finders #1648 [Yaroslav Markin]
+
 * Fixed that ActiveRecord::Base#new_record? should return false (not nil) for existing records #1219 [Yaroslav Markin]
 
 * I18n the word separator for error messages. Introduces the activerecord.errors.format.separator translation key.  #1294 [Akira Matsuda]
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index c428366a04..390c005785 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -51,6 +51,7 @@ module ActiveRecord
   autoload :Callbacks, 'active_record/callbacks'
   autoload :Dirty, 'active_record/dirty'
   autoload :DynamicFinderMatch, 'active_record/dynamic_finder_match'
+  autoload :DynamicScopeMatch, 'active_record/dynamic_scope_match'
   autoload :Migration, 'active_record/migration'
   autoload :Migrator, 'active_record/migration'
   autoload :NamedScope, 'active_record/named_scope'
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 5a60b13fd8..c154a5087c 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1216,11 +1216,11 @@ module ActiveRecord
         # callbacks will be executed after the association is wiped out.
         old_method = "destroy_without_habtm_shim_for_#{reflection.name}"
         class_eval <<-end_eval unless method_defined?(old_method)
-          alias_method :#{old_method}, :destroy_without_callbacks
-          def destroy_without_callbacks
-            #{reflection.name}.clear
-            #{old_method}
-          end
+          alias_method :#{old_method}, :destroy_without_callbacks  # alias_method :destroy_without_habtm_shim_for_posts, :destroy_without_callbacks
+          def destroy_without_callbacks                            # def destroy_without_callbacks
+            #{reflection.name}.clear                               #   posts.clear
+            #{old_method}                                          #   destroy_without_habtm_shim_for_posts
+          end                                                      # end
         end_eval
 
         add_association_callbacks(reflection.name, options)
@@ -1463,22 +1463,22 @@ module ActiveRecord
                 before_destroy method_name
               when :delete_all
                 module_eval %Q{
-                  before_destroy do |record|
-                    delete_all_has_many_dependencies(record,
-                      "#{reflection.name}",
-                      #{reflection.class_name},
-                      %@#{dependent_conditions}@)
-                  end
+                  before_destroy do |record|                  # before_destroy do |record|
+                    delete_all_has_many_dependencies(record,  #   delete_all_has_many_dependencies(record,
+                      "#{reflection.name}",                   #     "posts",
+                      #{reflection.class_name},               #     Post,
+                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
+                  end                                         # end
                 }
               when :nullify
                 module_eval %Q{
-                  before_destroy do |record|
-                    nullify_has_many_dependencies(record,
-                      "#{reflection.name}",
-                      #{reflection.class_name},
-                      "#{reflection.primary_key_name}",
-                      %@#{dependent_conditions}@)
-                  end
+                  before_destroy do |record|                  # before_destroy do |record|
+                    nullify_has_many_dependencies(record,     #   nullify_has_many_dependencies(record,
+                      "#{reflection.name}",                   #     "posts",
+                      #{reflection.class_name},               #     Post,
+                      "#{reflection.primary_key_name}",       #     "user_id",
+                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
+                  end                                         # end
                 }
               else
                 raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{reflection.options[:dependent].inspect})"
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index e5e94555eb..cca012ed55 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1456,7 +1456,10 @@ module ActiveRecord #:nodoc:
       def respond_to?(method_id, include_private = false)
         if match = DynamicFinderMatch.match(method_id)
           return true if all_attributes_exists?(match.attribute_names)
+        elsif match = DynamicScopeMatch.match(method_id)
+          return true if all_attributes_exists?(match.attribute_names)
         end
+        
         super
       end
 
@@ -1809,7 +1812,11 @@ module ActiveRecord #:nodoc:
         # This also enables you to initialize a record if it is not found, such as find_or_initialize_by_amount(amount)
         # or find_or_create_by_user_and_password(user, password).
         #
-        # Each dynamic finder or initializer/creator is also defined in the class after it is first invoked, so that future
+        # Also enables dynamic scopes like scoped_by_user_name(user_name) and scoped_by_user_name_and_password(user_name, password) that
+        # are turned into scoped(:conditions => ["user_name = ?", user_name]) and scoped(:conditions => ["user_name = ? AND password = ?", user_name, password])
+        # respectively.
+        #
+        # Each dynamic finder, scope or initializer/creator is also defined in the class after it is first invoked, so that future
         # attempts to use it do not run through method_missing.
         def method_missing(method_id, *arguments, &block)
           if match = DynamicFinderMatch.match(method_id)
@@ -1818,10 +1825,31 @@ module ActiveRecord #:nodoc:
             if match.finder?
               finder = match.finder
               bang = match.bang?
+              # def self.find_by_login_and_activated(*args)
+              #   options = args.extract_options!
+              #   attributes = construct_attributes_from_arguments(
+              #     [:login,:activated],
+              #     args
+              #   )
+              #   finder_options = { :conditions => attributes }
+              #   validate_find_options(options)
+              #   set_readonly_option!(options)
+              #
+              #   if options[:conditions]
+              #     with_scope(:find => finder_options) do
+              #       find(:first, options)
+              #     end
+              #   else
+              #     find(:first, options.merge(finder_options))
+              #   end
+              # end
               self.class_eval %{
                 def self.#{method_id}(*args)
                   options = args.extract_options!
-                  attributes = construct_attributes_from_arguments([:#{attribute_names.join(',:')}], args)
+                  attributes = construct_attributes_from_arguments(
+                    [:#{attribute_names.join(',:')}],
+                    args
+                  )
                   finder_options = { :conditions => attributes }
                   validate_find_options(options)
                   set_readonly_option!(options)
@@ -1839,6 +1867,31 @@ module ActiveRecord #:nodoc:
               send(method_id, *arguments)
             elsif match.instantiator?
               instantiator = match.instantiator
+              # def self.find_or_create_by_user_id(*args)
+              #   guard_protected_attributes = false
+              #
+              #   if args[0].is_a?(Hash)
+              #     guard_protected_attributes = true
+              #     attributes = args[0].with_indifferent_access
+              #     find_attributes = attributes.slice(*[:user_id])
+              #   else
+              #     find_attributes = attributes = construct_attributes_from_arguments([:user_id], args)
+              #   end
+              #
+              #   options = { :conditions => find_attributes }
+              #   set_readonly_option!(options)
+              #
+              #   record = find(:first, options)
+              #
+              #   if record.nil?
+              #     record = self.new { |r| r.send(:attributes=, attributes, guard_protected_attributes) }
+              #     yield(record) if block_given?
+              #     record.save
+              #     record
+              #   else
+              #     record
+              #   end
+              # end
               self.class_eval %{
                 def self.#{method_id}(*args)
                   guard_protected_attributes = false
@@ -1868,6 +1921,22 @@ module ActiveRecord #:nodoc:
               }, __FILE__, __LINE__
               send(method_id, *arguments, &block)
             end
+          elsif match = DynamicScopeMatch.match(method_id)
+            attribute_names = match.attribute_names
+            super unless all_attributes_exists?(attribute_names)
+            if match.scope?
+              self.class_eval %{
+                def self.#{method_id}(*args)                        # def self.scoped_by_user_name_and_password(*args)
+                  options = args.extract_options!                   #   options = args.extract_options!
+                  attributes = construct_attributes_from_arguments( #   attributes = construct_attributes_from_arguments(
+                    [:#{attribute_names.join(',:')}], args          #     [:user_name, :password], args
+                  )                                                 #   )
+                                                                    # 
+                  scoped(:conditions => attributes)                 #   scoped(:conditions => attributes)
+                end                                                 # end
+              }, __FILE__, __LINE__
+              send(method_id, *arguments)
+            end
           else
             super
           end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index 950bd72101..00c71090f3 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -14,12 +14,12 @@ module ActiveRecord
         def dirties_query_cache(base, *method_names)
           method_names.each do |method_name|
             base.class_eval <<-end_code, __FILE__, __LINE__
-              def #{method_name}_with_query_dirty(*args)
-                clear_query_cache if @query_cache_enabled
-                #{method_name}_without_query_dirty(*args)
-              end
-
-              alias_method_chain :#{method_name}, :query_dirty
+              def #{method_name}_with_query_dirty(*args)        # def update_with_query_dirty(*args)
+                clear_query_cache if @query_cache_enabled       #   clear_query_cache if @query_cache_enabled
+                #{method_name}_without_query_dirty(*args)       #   update_without_query_dirty(*args)
+              end                                               # end
+                                                                #
+              alias_method_chain :#{method_name}, :query_dirty  # alias_method_chain :update, :query_dirty
             end_code
           end
         end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index fe9cbcf024..273f823e7f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -476,12 +476,12 @@ module ActiveRecord
 
       %w( string text integer float decimal datetime timestamp time date binary boolean ).each do |column_type|
         class_eval <<-EOV
-          def #{column_type}(*args)
-            options = args.extract_options!
-            column_names = args
-
-            column_names.each { |name| column(name, '#{column_type}', options) }
-          end
+          def #{column_type}(*args)                                               # def string(*args)
+            options = args.extract_options!                                       #   options = args.extract_options!
+            column_names = args                                                   #   column_names = args
+                                                                                  #
+            column_names.each { |name| column(name, '#{column_type}', options) }  #   column_names.each { |name| column(name, 'string', options) }
+          end                                                                     # end
         EOV
       end
 
@@ -676,24 +676,24 @@ module ActiveRecord
       #  t.string(:goat, :sheep)
       %w( string text integer float decimal datetime timestamp time date binary boolean ).each do |column_type|
         class_eval <<-EOV
-          def #{column_type}(*args)
-            options = args.extract_options!
-            column_names = args
-
-            column_names.each do |name|
-              column = ColumnDefinition.new(@base, name, '#{column_type}')
-              if options[:limit]
-                column.limit = options[:limit]
-              elsif native['#{column_type}'.to_sym].is_a?(Hash)
-                column.limit = native['#{column_type}'.to_sym][:limit]
-              end
-              column.precision = options[:precision]
-              column.scale = options[:scale]
-              column.default = options[:default]
-              column.null = options[:null]
-              @base.add_column(@table_name, name, column.sql_type, options)
-            end
-          end
+          def #{column_type}(*args)                                          # def string(*args)
+            options = args.extract_options!                                  #   options = args.extract_options!
+            column_names = args                                              #   column_names = args
+                                                                             #
+            column_names.each do |name|                                      #   column_names.each do |name|
+              column = ColumnDefinition.new(@base, name, '#{column_type}')   #     column = ColumnDefinition.new(@base, name, 'string')
+              if options[:limit]                                             #     if options[:limit]
+                column.limit = options[:limit]                               #       column.limit = options[:limit]
+              elsif native['#{column_type}'.to_sym].is_a?(Hash)              #     elsif native['string'.to_sym].is_a?(Hash)
+                column.limit = native['#{column_type}'.to_sym][:limit]       #       column.limit = native['string'.to_sym][:limit]
+              end                                                            #     end
+              column.precision = options[:precision]                         #     column.precision = options[:precision]
+              column.scale = options[:scale]                                 #     column.scale = options[:scale]
+              column.default = options[:default]                             #     column.default = options[:default]
+              column.null = options[:null]                                   #     column.null = options[:null]
+              @base.add_column(@table_name, name, column.sql_type, options)  #     @base.add_column(@table_name, name, column.sql_type, options)
+            end                                                              #   end
+          end                                                                # end
         EOV
       end
 
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 46d4b6c89c..60729c63db 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -13,23 +13,25 @@ module MysqlCompat #:nodoc:
     # C driver >= 2.7 returns null values in each_hash
     if Mysql.const_defined?(:VERSION) && (Mysql::VERSION.is_a?(String) || Mysql::VERSION >= 20700)
       target.class_eval <<-'end_eval'
-      def all_hashes
-        rows = []
-        each_hash { |row| rows << row }
-        rows
-      end
+      def all_hashes                     # def all_hashes
+        rows = []                        #   rows = []
+        each_hash { |row| rows << row }  #   each_hash { |row| rows << row }
+        rows                             #   rows
+      end                                # end
       end_eval
 
     # adapters before 2.7 don't have a version constant
     # and don't return null values in each_hash
     else
       target.class_eval <<-'end_eval'
-      def all_hashes
-        rows = []
-        all_fields = fetch_fields.inject({}) { |fields, f| fields[f.name] = nil; fields }
-        each_hash { |row| rows << all_fields.dup.update(row) }
-        rows
-      end
+      def all_hashes                                            # def all_hashes
+        rows = []                                               #   rows = []
+        all_fields = fetch_fields.inject({}) { |fields, f|      #   all_fields = fetch_fields.inject({}) { |fields, f|
+          fields[f.name] = nil; fields                          #     fields[f.name] = nil; fields
+        }                                                       #   }
+        each_hash { |row| rows << all_fields.dup.update(row) }  #   each_hash { |row| rows << all_fields.dup.update(row) }
+        rows                                                    #   rows
+      end                                                       # end
       end_eval
     end
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 60ec01b95e..6685cb8663 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -950,13 +950,13 @@ module ActiveRecord
           # should know about this but can't detect it there, so deal with it here.
           money_precision = (postgresql_version >= 80300) ? 19 : 10
           PostgreSQLColumn.module_eval(<<-end_eval)
-            def extract_precision(sql_type)
-              if sql_type =~ /^money$/
-                #{money_precision}
-              else
-                super
-              end
-            end
+            def extract_precision(sql_type)  # def extract_precision(sql_type)
+              if sql_type =~ /^money$/       #   if sql_type =~ /^money$/
+                #{money_precision}           #     19
+              else                           #   else
+                super                        #     super
+              end                            #   end
+            end                              # end
           end_eval
 
           configure_connection
diff --git a/activerecord/lib/active_record/dirty.rb b/activerecord/lib/active_record/dirty.rb
index a1760875ba..4c899f58e5 100644
--- a/activerecord/lib/active_record/dirty.rb
+++ b/activerecord/lib/active_record/dirty.rb
@@ -174,7 +174,7 @@ module ActiveRecord
         alias_attribute_without_dirty(new_name, old_name)
         DIRTY_SUFFIXES.each do |suffix|
           module_eval <<-STR, __FILE__, __LINE__+1
-            def #{new_name}#{suffix}; self.#{old_name}#{suffix}; end
+            def #{new_name}#{suffix}; self.#{old_name}#{suffix}; end  # def subject_changed?; self.title_changed?; end
           STR
         end
       end
diff --git a/activerecord/lib/active_record/dynamic_scope_match.rb b/activerecord/lib/active_record/dynamic_scope_match.rb
new file mode 100644
index 0000000000..f796ba669a
--- /dev/null
+++ b/activerecord/lib/active_record/dynamic_scope_match.rb
@@ -0,0 +1,25 @@
+module ActiveRecord
+  class DynamicScopeMatch
+    def self.match(method)
+      ds_match = self.new(method)
+      ds_match.scope ? ds_match : nil
+    end
+
+    def initialize(method)
+      @scope = true
+      case method.to_s
+      when /^scoped_by_([_a-zA-Z]\w*)$/
+        names = $1
+      else
+        @scope = nil
+      end
+      @attribute_names = names && names.split('_and_')
+    end
+
+    attr_reader :scope, :attribute_names
+
+    def scope?
+      !@scope.nil?
+    end
+  end
+end
diff --git a/activerecord/test/cases/named_scope_test.rb b/activerecord/test/cases/named_scope_test.rb
index 64e899780c..b152f95a15 100644
--- a/activerecord/test/cases/named_scope_test.rb
+++ b/activerecord/test/cases/named_scope_test.rb
@@ -278,3 +278,23 @@ class NamedScopeTest < ActiveRecord::TestCase
     assert_equal post.comments.size, Post.scoped(:joins => join).scoped(:joins => join, :conditions => "posts.id = #{post.id}").size
   end
 end
+
+class DynamicScopeMatchTest < ActiveRecord::TestCase  
+  def test_scoped_by_no_match
+    assert_nil ActiveRecord::DynamicScopeMatch.match("not_scoped_at_all")
+  end
+
+  def test_scoped_by
+    match = ActiveRecord::DynamicScopeMatch.match("scoped_by_age_and_sex_and_location")
+    assert_not_nil match
+    assert match.scope?
+    assert_equal %w(age sex location), match.attribute_names
+  end
+end
+
+class DynamicScopeTest < ActiveRecord::TestCase
+  def test_dynamic_scope
+    assert_equal Post.scoped_by_author_id(1).find(1), Post.find(1)
+    assert_equal Post.scoped_by_author_id_and_title(1, "Welcome to the weblog").first, Post.find(:first, :conditions => { :author_id => 1, :title => "Welcome to the weblog"})
+  end
+end