Remove ActiveRecord::Model

In the end I think the pain of implementing this seamlessly was not
worth the gain provided.

The intention was that it would allow plain ruby objects that might not
live in your main application to be subclassed and have persistence
mixed in. But I've decided that the benefit of doing that is not worth
the amount of complexity that the implementation introduced.

1 files changed, 71 insertions, 73 deletions

diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index f97c363871..b21765aa75 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -4,73 +4,6 @@ require 'thread'
 
 module ActiveRecord
   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
-
-    ##
-    # :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:
-    # 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:
-    # 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:
-    # Specify whether or not to use timestamps for migration versions
-    mattr_accessor :timestamped_migrations, instance_accessor: false
-    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
@@ -79,12 +12,71 @@ module ActiveRecord
     included do
       ##
       # :singleton-method:
-      # The connection handler
-      config_attribute :connection_handler
+      #
+      # 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_writer: false
 
-      %w(logger configurations default_timezone schema_format timestamped_migrations).each do |name|
-        config_attribute name, global: true
-      end
+      ##
+      # :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_writer: false
+      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_writer: false
+      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_writer: false
+      self.schema_format = :ruby
+
+      ##
+      # :singleton-method:
+      # Specify whether or not to use timestamps for migration versions
+      mattr_accessor :timestamped_migrations, instance_writer: false
+      self.timestamped_migrations = true
+
+      class_attribute :connection_handler, instance_writer: false
+      self.connection_handler = ConnectionAdapters::ConnectionHandler.new
+
+      mattr_accessor :dependent_restrict_raises, instance_writer: false
+      self.dependent_restrict_raises = true
     end
 
     module ClassMethods
@@ -139,7 +131,13 @@ module ActiveRecord
 
       # Returns the Arel engine.
       def arel_engine
-        @arel_engine ||= connection_handler.retrieve_connection_pool(self) ? self : active_record_super.arel_engine
+        @arel_engine ||= begin
+          if Base == self || connection_handler.retrieve_connection_pool(self)
+            self
+          else
+            superclass.arel_engine
+          end
+       end
       end
 
       private