require 'rails/engine' require 'active_support/core_ext/array/conversions' module Rails # Rails::Plugin is nothing more than a Rails::Engine, but since it's loaded too late # in the boot process, it does not have the same configuration powers as a bare # Rails::Engine. # # Opposite to Rails::Railtie and Rails::Engine, you are not supposed to inherit from # Rails::Plugin. Rails::Plugin is automatically configured to be an engine by simply # placing inside vendor/plugins. Since this is done automatically, you actually cannot # declare a Rails::Engine inside your Plugin, otherwise it would cause the same files # to be loaded twice. This means that if you want to ship an Engine as gem it cannot # be used as plugin and vice-versa. # # Besides this conceptual difference, the only difference between Rails::Engine and # Rails::Plugin is that plugins automatically load the file "init.rb" at the plugin # root during the boot process. # class Plugin < Engine def self.global_plugins @global_plugins ||= [] end def self.inherited(base) raise "You cannot inherit from Rails::Plugin" end def self.all(list, paths) plugins = [] paths.each do |path| Dir["#{path}/*"].each do |plugin_path| plugin = new(plugin_path) next unless list.include?(plugin.name) || list.include?(:all) if global_plugins.include?(plugin.name) warn "WARNING: plugin #{plugin.name} from #{path} was not loaded. Plugin with the same name has been already loaded." next end global_plugins << plugin.name plugins << plugin end end plugins.sort_by do |p| [list.index(p.name) || list.index(:all), p.name.to_s] end end attr_reader :name, :path def railtie_name name.to_s end def initialize(root) @name = File.basename(root).to_sym config.root = root end def config @config ||= Engine::Configuration.new end initializer :handle_lib_autoload, :before => :set_load_path do |app| paths = if app.config.reload_plugins config.autoload_paths else config.autoload_once_paths end paths.concat config.paths.lib.to_a end initializer :load_init_rb, :before => :load_config_initializers do |app| init_rb = File.expand_path("init.rb", root) if File.file?(init_rb) config = app.config # TODO: think about evaling initrb in context of Engine (currently it's # always evaled in context of Rails::Application) eval(File.read(init_rb), binding, init_rb) end end initializer :sanity_check_railties_collision do if Engine.subclasses.map { |k| k.root.to_s }.include?(root.to_s) raise "\"#{name}\" is a Railtie/Engine and cannot be installed as plugin" end end end end