From 54c43f76ec6a13064f4f013a8f7f5d22cae20912 Mon Sep 17 00:00:00 2001
From: Luca Guidi <guidi.luca@gmail.com>
Date: Tue, 24 Feb 2009 15:26:56 +0100
Subject: [PATCH] Database Rake tasks for engine migrations

---
 railties/lib/initializer.rb         |    4 +++
 railties/lib/rails/plugin/loader.rb |    1 +
 railties/lib/tasks/databases.rake   |   36 +++++++++++++++++++++++++++++++++++
 railties/test/initializer_test.rb   |   12 +++++++++++
 4 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index a31ae94..7a7c332 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -71,6 +71,10 @@ module Rails
     def public_path=(path)
       @@public_path = path
     end
+
+    def plugins
+      @@plugins ||= ActiveSupport::OrderedHash.new
+    end
   end
 
   # The Initializer is responsible for processing the Rails configuration, such
diff --git a/railties/lib/rails/plugin/loader.rb b/railties/lib/rails/plugin/loader.rb
index 7f85bb8..30a5f93 100644
--- a/railties/lib/rails/plugin/loader.rb
+++ b/railties/lib/rails/plugin/loader.rb
@@ -103,6 +103,7 @@ module Rails
 
         def register_plugin_as_loaded(plugin)
           initializer.loaded_plugins << plugin
+          Rails.plugins[plugin.name] = plugin
         end
 
         def configuration
diff --git a/railties/lib/tasks/databases.rake b/railties/lib/tasks/databases.rake
index 9588fab..e4e736c 100644
--- a/railties/lib/tasks/databases.rake
+++ b/railties/lib/tasks/databases.rake
@@ -147,6 +147,42 @@ namespace :db do
       ActiveRecord::Migrator.run(:down, "db/migrate/", version)
       Rake::Task["db:schema:dump"].invoke if ActiveRecord::Base.schema_format == :ruby
     end
+
+    desc 'Runs migrations from engines.'
+    task :engines => :environment do
+      engines = if ENV["ENGINE"]
+        raise "Unknown engine: #{ENV["ENGINE"]}" unless Rails.plugins.key?(ENV["ENGINE"])
+        Hash[ENV["ENGINE"], Rails.plugins[ENV["ENGINE"]]]
+      else
+        Rails.plugins
+      end
+
+      engines.each do |name, engine|
+        engine_migrations_path = "#{engine.directory}/db/migrate"
+        next unless File.exist?(engine_migrations_path)
+        ActiveRecord::Migrator.migrate(engine_migrations_path)
+        Rake::Task["db:schema:dump"].invoke if ActiveRecord::Base.schema_format == :ruby
+      end
+    end
+
+    namespace :engines do
+      desc 'Runs the "down" for migrations from engines.'
+      task :down => :environment do
+        engines = if ENV["ENGINE"]
+          raise "Unknown engine: #{ENV["ENGINE"]}" unless Rails.plugins.key?(ENV["ENGINE"])
+          Hash[ENV["ENGINE"], Rails.plugins[ENV["ENGINE"]]]
+        else
+          Rails.plugins
+        end
+
+        engines.each do |name, engine|
+          engine_migrations_path = "#{engine.directory}/db/migrate"
+          next unless File.exist?(engine_migrations_path)
+          ActiveRecord::Migrator.down(engine_migrations_path)
+          Rake::Task["db:schema:dump"].invoke if ActiveRecord::Base.schema_format == :ruby
+        end
+      end
+    end
   end
 
   desc 'Rolls the schema back to the previous version. Specify the number of steps with STEP=n'
diff --git a/railties/test/initializer_test.rb b/railties/test/initializer_test.rb
index eb9ec75..1d70033 100644
--- a/railties/test/initializer_test.rb
+++ b/railties/test/initializer_test.rb
@@ -187,6 +187,7 @@ class InitializerPluginLoadingTests < Test::Unit::TestCase
     @initializer       = Rails::Initializer.new(@configuration)
     @valid_plugin_path = plugin_fixture_path('default/stubby')
     @empty_plugin_path = plugin_fixture_path('default/empty')
+    Rails.plugins.clear
   end
 
   def test_no_plugins_are_loaded_if_the_configuration_has_an_empty_plugin_list
@@ -268,6 +269,17 @@ class InitializerPluginLoadingTests < Test::Unit::TestCase
     assert $LOAD_PATH.include?(File.join(plugin_fixture_path('default/acts/acts_as_chunky_bacon'), 'lib'))
   end
 
+  def test_should_store_loaded_plugins_in_rails_module
+    load_plugins!
+    assert_plugins [:a, :acts_as_chunky_bacon, :engine, :gemlike, :plugin_with_no_lib_dir, :stubby], Rails.plugins.values
+  end
+
+  def test_should_store_only_specified_plugins_in_rails_module
+    plugin_names = [:plugin_with_no_lib_dir, :acts_as_chunky_bacon]
+    only_load_the_following_plugins! plugin_names
+    load_plugins!
+    assert_plugins plugin_names, Rails.plugins.values
+  end
 
   private
 
-- 
1.5.4.5