Run engine commands through command infrastructure.

2 files changed, 35 insertions, 6 deletions

diff --git a/railties/lib/rails/command/actions.rb b/railties/lib/rails/command/actions.rb
index 52d3348db3..31b656ec31 100644
--- a/railties/lib/rails/command/actions.rb
+++ b/railties/lib/rails/command/actions.rb
@@ -1,18 +1,42 @@
 module Rails
   module Command
     module Actions
-      private
-        # Change to the application's path if there is no config.ru file in current directory.
-        # This allows us to run `rails server` from other directories, but still get
-        # the main config.ru and properly set the tmp directory.
-        def set_application_directory!
-          Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
+      # Change to the application's path if there is no config.ru file in current directory.
+      # This allows us to run `rails server` from other directories, but still get
+      # the main config.ru and properly set the tmp directory.
+      def set_application_directory!
+        Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
+      end
+
+      if defined?(ENGINE_PATH)
+        def require_application_and_environment!
+          require ENGINE_PATH
         end
 
+        def load_tasks
+          Rake.application.init("rails")
+          Rake.application.load_rakefile
+        end
+
+        def load_generators
+          engine = ::Rails::Engine.find(ENGINE_ROOT)
+          Rails::Generators.namespace = engine.railtie_namespace
+          engine.load_generators
+        end
+      else
         def require_application_and_environment!
           require APP_PATH
           Rails.application.require_environment!
         end
+
+        def load_tasks
+          Rails.application.load_tasks
+        end
+
+        def load_generators
+          Rails.application.load_generators
+        end
+      end
     end
   end
 end
diff --git a/railties/lib/rails/command/base.rb b/railties/lib/rails/command/base.rb
index 2ef8393863..73ebaca66f 100644
--- a/railties/lib/rails/command/base.rb
+++ b/railties/lib/rails/command/base.rb
@@ -15,6 +15,11 @@ module Rails
       include Actions
 
       class << self
+        # Returns true when the app is a Rails engine.
+        def engine?
+          defined?(ENGINE_ROOT)
+        end
+
         # Tries to get the description from a USAGE file one folder above the command
         # root.
         def desc(usage = nil, description = nil)