Simplify AR configuration code.

Get rid of ActiveModel::Configuration, make better use of
ActiveSupport::Concern + class_attribute, etc.

1 files changed, 74 insertions, 63 deletions

diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index dbad561ca2..f5d60d11b6 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -1,80 +1,88 @@
 require 'active_support/concern'
 require 'active_support/core_ext/hash/indifferent_access'
 require 'active_support/core_ext/object/deep_dup'
+require 'active_support/core_ext/module/delegation'
 require 'thread'
 
 module ActiveRecord
-  module Core
-    extend ActiveSupport::Concern
+  ActiveSupport.on_load(:active_record_config) do
+    ##
+    # :singleton-method:
+    #
+    # Accepts a logger conforming to the interface of Log4r which is then
+    # passed on to any new database connections made and which can be
+    # retrieved on both a class and instance level by calling +logger+.
+    mattr_accessor :logger, instance_accessor: false
 
-    included do
-      ##
-      # :singleton-method:
-      #
-      # Accepts a logger conforming to the interface of Log4r which is then
-      # passed on to any new database connections made and which can be
-      # retrieved on both a class and instance level by calling +logger+.
-      config_attribute :logger, :global => true
+    ##
+    # :singleton-method:
+    # Contains the database configuration - as is typically stored in config/database.yml -
+    # as a Hash.
+    #
+    # For example, the following database.yml...
+    #
+    #   development:
+    #     adapter: sqlite3
+    #     database: db/development.sqlite3
+    #
+    #   production:
+    #     adapter: sqlite3
+    #     database: db/production.sqlite3
+    #
+    # ...would result in ActiveRecord::Base.configurations to look like this:
+    #
+    #   {
+    #      'development' => {
+    #         'adapter'  => 'sqlite3',
+    #         'database' => 'db/development.sqlite3'
+    #      },
+    #      'production' => {
+    #         'adapter'  => 'sqlite3',
+    #         'database' => 'db/production.sqlite3'
+    #      }
+    #   }
+    mattr_accessor :configurations, instance_accessor: false
+    self.configurations = {}
 
-      ##
-      # :singleton-method:
-      # Contains the database configuration - as is typically stored in config/database.yml -
-      # as a Hash.
-      #
-      # For example, the following database.yml...
-      #
-      #   development:
-      #     adapter: sqlite3
-      #     database: db/development.sqlite3
-      #
-      #   production:
-      #     adapter: sqlite3
-      #     database: db/production.sqlite3
-      #
-      # ...would result in ActiveRecord::Base.configurations to look like this:
-      #
-      #   {
-      #      'development' => {
-      #         'adapter'  => 'sqlite3',
-      #         'database' => 'db/development.sqlite3'
-      #      },
-      #      'production' => {
-      #         'adapter'  => 'sqlite3',
-      #         'database' => 'db/production.sqlite3'
-      #      }
-      #   }
-      config_attribute :configurations, :global => true
-      self.configurations = {}
+    ##
+    # :singleton-method:
+    # Determines whether to use Time.utc (using :utc) or Time.local (using :local) when pulling
+    # dates and times from the database. This is set to :utc by default.
+    mattr_accessor :default_timezone, instance_accessor: false
+    self.default_timezone = :utc
 
-      ##
-      # :singleton-method:
-      # Determines whether to use Time.utc (using :utc) or Time.local (using :local) when pulling
-      # dates and times from the database. This is set to :utc by default.
-      config_attribute :default_timezone, :global => true
-      self.default_timezone = :utc
+    ##
+    # :singleton-method:
+    # Specifies the format to use when dumping the database schema with Rails'
+    # Rakefile. If :sql, the schema is dumped as (potentially database-
+    # specific) SQL statements. If :ruby, the schema is dumped as an
+    # ActiveRecord::Schema file which can be loaded into any database that
+    # supports migrations. Use :ruby if you want to have different database
+    # adapters for, e.g., your development and test environments.
+    mattr_accessor :schema_format, instance_accessor: false
+    self.schema_format = :ruby
 
-      ##
-      # :singleton-method:
-      # Specifies the format to use when dumping the database schema with Rails'
-      # Rakefile. If :sql, the schema is dumped as (potentially database-
-      # specific) SQL statements. If :ruby, the schema is dumped as an
-      # ActiveRecord::Schema file which can be loaded into any database that
-      # supports migrations. Use :ruby if you want to have different database
-      # adapters for, e.g., your development and test environments.
-      config_attribute :schema_format, :global => true
-      self.schema_format = :ruby
+    ##
+    # :singleton-method:
+    # Specify whether or not to use timestamps for migration versions
+    mattr_accessor :timestamped_migrations, instance_accessor: false
+    self.timestamped_migrations = true
 
-      ##
-      # :singleton-method:
-      # Specify whether or not to use timestamps for migration versions
-      config_attribute :timestamped_migrations, :global => true
-      self.timestamped_migrations = true
+    mattr_accessor :connection_handler, instance_accessor: false
+    self.connection_handler = ConnectionAdapters::ConnectionHandler.new
+
+    mattr_accessor :dependent_restrict_raises, instance_accessor: false
+    self.dependent_restrict_raises = true
+  end
 
+  module Core
+    extend ActiveSupport::Concern
+
+    included do
       ##
       # :singleton-method:
       # The connection handler
       config_attribute :connection_handler
-      self.connection_handler = ConnectionAdapters::ConnectionHandler.new
 
       ##
       # :singleton-method:
@@ -83,8 +91,11 @@ module ActiveRecord
       # ActiveRecord::DeleteRestrictionError exception will be raised
       # along with a DEPRECATION WARNING. If set to false, an error would
       # be added to the model instead.
-      config_attribute :dependent_restrict_raises, :global => true
-      self.dependent_restrict_raises = true
+      config_attribute :dependent_restrict_raises
+
+      %w(logger configurations default_timezone schema_format timestamped_migrations).each do |name|
+        config_attribute name, global: true
+      end
     end
 
     module ClassMethods