Adds support for datamapper session stores

Usage:

Replace the content of

  * config/initializers/session_store.rb

with the following:

  require 'dm-rails/session_store'
  Rails.application.config.session_store(
    Rails::DataMapper::SessionStore
  }

[#1278 state:resolved]

lib/dm-rails/railties/database.rake

@@ -110,14 +110,16 @@ namespace :db do
     task :create => :environment do
       require 'dm-rails/session_store'
       Rails::DataMapper::SessionStore::Session.auto_migrate!
-      ::DataMapper.logger.info "Created '#{Rails::DataMapper.configurations[Rails.env]['database']}.sessions'"
+      database = Rails::DataMapper.configuration.repositories[Rails.env]['database']
+      ::DataMapper.logger.info "Created '#{database}.sessions'"
     end
 
     desc "Clear the sessions table for DataMapperStore"
     task :clear => :environment do
       require 'dm-rails/session_store'
       Rails::DataMapper::SessionStore::Session.destroy!
-      ::DataMapper.logger.info "Deleted entries from '#{Rails::DataMapper.configurations[Rails.env]['database']}.sessions'"
+      database = Rails::DataMapper.configuration.repositories[Rails.env]['database']
+      ::DataMapper.logger.info "Deleted entries from '#{database}.sessions'"
     end
   end
 

lib/dm-rails/session_store.rb

@@ -1,4 +1,5 @@
 require 'dm-core'
+require 'active_support/core_ext/class/attribute'
 
 # Implements DataMapper-specific session store.
 
@@ -13,18 +14,22 @@ class Session
 
         property :id,         Serial
         property :session_id, String,   :required => true, :unique => true
-        property :data,       Object,   :required => true, :default => ActiveSupport::Base64.encode64(Marshal.dump({}))
+        property :data,       Object,   :required => true
         property :updated_at, DateTime,                    :index => true
 
         def self.name
           'session'
         end
 
+        def data
+          attribute_get(:data) || {}
+        end
+
       end
 
       SESSION_RECORD_KEY = 'rack.session.record'.freeze
 
-      cattr_accessor :session_class
+      class_attribute :session_class
       self.session_class = Session
 
       private