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351816fab6
Also create a engine_blank_point initializer to ensure any :before or :after hooks defined inside engines won't move the configuration initializers to other places.
226 lines
7.7 KiB
Ruby
226 lines
7.7 KiB
Ruby
require 'rails/railtie'
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require 'active_support/core_ext/module/delegation'
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require 'pathname'
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require 'rbconfig'
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module Rails
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# Rails::Engine allows you to wrap a specific Rails application and share it accross
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# different applications. Since Rails 3.0, every Rails::Application is nothing
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# more than an Engine, allowing you to share it very easily.
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#
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# Any Rails::Engine is also a Rails::Railtie, so the same methods (like rake_tasks and
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# generators) and configuration available in the latter can also be used in the former.
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#
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# == Creating an Engine
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#
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# In Rails versions before to 3.0, your gems automatically behaved as Engine, however
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# this coupled Rails to Rubygems. Since Rails 3.0, if you want a gem to automatically
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# behave as Engine, you have to specify an Engine for it somewhere inside your plugin
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# lib folder (similar with how we spceify a Railtie):
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#
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# # lib/my_engine.rb
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# module MyEngine
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# class Engine < Rails::Engine
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# end
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# end
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#
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# Then ensure that this file is loaded at the top of your config/application.rb (or in
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# your Gemfile) and it will automatically load models, controllers, helpers and metals
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# inside app, load routes at "config/routes.rb", load locales at "config/locales/*",
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# load tasks at "lib/tasks/*".
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#
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# == Configuration
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#
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# Besides the Railtie configuration which is shared across the application, in a
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# Rails::Engine you can access load_paths, eager_load_paths and load_once_paths,
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# which differently from a Railtie, are scoped to the current Engine.
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#
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# Example:
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#
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# class MyEngine < Rails::Engine
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# # Add a load path for this specific Engine
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# config.load_paths << File.expand_path("../lib/some/path", __FILE__)
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#
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# initializer "my_engine.add_middleware" do |app|
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# app.middleware.use MyEngine::Middleware
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# end
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# end
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#
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# == Paths
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#
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# Since Rails 3.0, both your Application and Engines do not have hardcoded paths.
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# This means that you are not required to place your controllers at "app/controllers",
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# but in any place which you find convenient.
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#
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# For example, let's suppose you want to lay your controllers at lib/controllers, all
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# you need to do is:
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#
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# class MyEngine < Rails::Engine
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# paths.app.controllers = "lib/controllers"
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# end
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#
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# You can also have your controllers being loaded from both "app/controllers" and
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# "lib/controllers":
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#
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# class MyEngine < Rails::Engine
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# paths.app.controllers << "lib/controllers"
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# end
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#
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# The available paths in an Engine are:
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#
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# class MyEngine < Rails::Engine
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# paths.app = "app"
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# paths.app.controllers = "app/controllers"
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# paths.app.helpers = "app/helpers"
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# paths.app.models = "app/models"
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# paths.app.metals = "app/metal"
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# paths.app.views = "app/views"
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# paths.lib = "lib"
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# paths.lib.tasks = "lib/tasks"
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# paths.config = "config"
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# paths.config.initializers = "config/initializers"
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# paths.config.locales = "config/locales"
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# paths.config.routes = "config/routes.rb"
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# end
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#
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# Your Application class adds a couple more paths to this set. And as in your Application,
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# all folders under "app" are automatically added to the load path. So if you have
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# "app/observers", it's added by default.
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#
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class Engine < Railtie
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autoload :Configurable, "rails/engine/configurable"
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autoload :Configuration, "rails/engine/configuration"
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class << self
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attr_accessor :called_from
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# TODO Remove this. It's deprecated.
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alias :engine_name :railtie_name
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def inherited(base)
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unless base.abstract_railtie?
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base.called_from = begin
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# Remove the line number from backtraces making sure we don't leave anything behind
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call_stack = caller.map { |p| p.split(':')[0..-2].join(':') }
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File.dirname(call_stack.detect { |p| p !~ %r[railties[\w\-\.]*/lib/rails|rack[\w\-\.]*/lib/rack] })
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end
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end
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super
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end
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def find_root_with_flag(flag, default=nil)
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root_path = self.called_from
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while root_path && File.directory?(root_path) && !File.exist?("#{root_path}/#{flag}")
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parent = File.dirname(root_path)
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root_path = parent != root_path && parent
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end
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root = File.exist?("#{root_path}/#{flag}") ? root_path : default
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raise "Could not find root path for #{self}" unless root
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Config::CONFIG['host_os'] =~ /mswin|mingw/ ?
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Pathname.new(root).expand_path : Pathname.new(root).realpath
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end
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end
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delegate :paths, :root, :to => :config
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def load_tasks
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super
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config.paths.lib.tasks.to_a.sort.each { |ext| load(ext) }
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end
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def eager_load!
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config.eager_load_paths.each do |load_path|
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matcher = /\A#{Regexp.escape(load_path)}\/(.*)\.rb\Z/
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Dir.glob("#{load_path}/**/*.rb").sort.each do |file|
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require_dependency file.sub(matcher, '\1')
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end
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end
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end
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# Add configured load paths to ruby load paths and remove duplicates.
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initializer :set_load_path, :before => :bootstrap_hook do
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config.load_paths.reverse_each do |path|
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$LOAD_PATH.unshift(path) if File.directory?(path)
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end
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$LOAD_PATH.uniq!
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end
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# Set the paths from which Rails will automatically load source files,
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# and the load_once paths.
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#
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# This needs to be an initializer, since it needs to run once
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# per engine and get the engine as a block parameter
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initializer :set_autoload_paths, :before => :bootstrap_hook do |app|
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ActiveSupport::Dependencies.load_paths.unshift(*config.load_paths)
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if reloadable?(app)
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ActiveSupport::Dependencies.load_once_paths.unshift(*config.load_once_paths)
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else
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ActiveSupport::Dependencies.load_once_paths.unshift(*config.load_paths)
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end
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# Freeze so future modifications will fail rather than do nothing mysteriously
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config.load_paths.freeze
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config.load_once_paths.freeze
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end
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initializer :add_routing_paths do |app|
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paths.config.routes.to_a.each do |route|
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app.routes_reloader.paths.unshift(route) if File.exists?(route)
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end
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end
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# DEPRECATED: Remove in 3.1
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initializer :add_routing_namespaces do |app|
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paths.app.controllers.to_a.each do |load_path|
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load_path = File.expand_path(load_path)
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Dir["#{load_path}/*/**/*_controller.rb"].collect do |path|
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namespace = File.dirname(path).sub(/#{Regexp.escape(load_path)}\/?/, '')
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app.routes.controller_namespaces << namespace unless namespace.empty?
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end
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end
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end
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# I18n load paths are a special case since the ones added
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# later have higher priority.
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initializer :add_locales do
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config.i18n.railties_load_path.concat(paths.config.locales.to_a)
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end
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initializer :add_view_paths do
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views = paths.app.views.to_a
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ActiveSupport.on_load(:action_controller) do
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prepend_view_path(views)
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end
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ActiveSupport.on_load(:action_mailer) do
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prepend_view_path(views)
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end
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end
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initializer :add_metals do |app|
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app.metal_loader.paths.unshift(*paths.app.metals.to_a)
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end
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initializer :load_config_initializers do
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paths.config.initializers.to_a.sort.each do |initializer|
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load(initializer)
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end
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end
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initializer :engines_blank_point do
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# We need this initializer so all extra initializers added in engines are
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# consistently executed after all the initializers above across all engines.
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end
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protected
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def reloadable?(app)
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app.config.reload_engines
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end
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end
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end
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