class Rails::Application
application other than Rails.application
, then you must run them manually.
If you decide to define rake tasks, runners, or initializers in an
the configuration.
on one of the applications to create a copy of the application which shares
to initialize the second application. You can also use the initialize_copy
In the above example, the configuration from the first application was used
second_application = Application.new(config: first_application.config)
first_application = Application.new
end
class Application < Rails::Application
that has already been created:
To create a new application, you can instantiate a new instance of a class
it with a different application.
that is initialized will be set to Rails.application
, unless you override
If you decide to define multiple applications, then the first application
== Multiple Applications
11) Run config.after_initialize callbacks
10) Run config.before_eager_load and eager_load! if eager_load is true
9) Build the middleware stack and run to_prepare callbacks
8) Custom Railtie#initializers added by railties, engines and applications are executed
One by one, each engine sets up its load paths, routes and runs its config/initializers/* files.
7) Run Railtie#initializer defined by railties, engines and application.
6) Run config.before_initialize callbacks
5) Load config/environments/ENV.rb
4) Run config.before_configuration callbacks
3) Define Rails.application as “class MyApp::Application < Rails::Application”
2) require railties and engines
1) require “config/boot.rb” to setup load paths
the booting process goes like this:
process. From the moment you require “config/application.rb” in your app,
The application is also responsible for setting up and executing the booting
== Booting process
The Application is also responsible for building the middleware stack.
== Middlewares
whenever the files change in development.
The application object is also responsible for holding the routes and reloading routes
== Routes
Check Rails::Application::Configuration to see them all.
“logger” and so forth.
“cache_classes”, “consider_all_requests_local”, “filter_parameters”,
the application object has several specific configurations, for example
Besides providing the same configuration as Rails::Engine and Rails::Railtie,
== Configuration
are executed (check Rails::Application::Finisher).
Rails::Application::Bootstrap) and finishing initializers, after all the others
initializers. It also executes some bootstrap initializers (check
Rails::Application is responsible for executing all railties and engines
== Initialization
An Engine with the responsibility of coordinating the whole boot process.
def self.add_lib_to_load_path!(root) #:nodoc:
you need to load files in lib/ during the application configuration as well.
Rails application, you will need to add lib to $LOAD_PATH on your own in case
are changing config.root inside your application definition or having a custom
Notice this method takes into consideration the default root path. So if you
end
config.i18n.backend = MyBackend
require "my_backend" # in lib/my_backend
class MyApplication < Rails::Application
configuration.
allowing the developer to load classes in lib and use them during application
This method is called just after an application inherits from Rails::Application,
def self.add_lib_to_load_path!(root) #:nodoc: path = File.join root, 'lib' if File.exist?(path) && !$LOAD_PATH.include?(path) $LOAD_PATH.unshift(path) end end
def build_middleware
def build_middleware config.app_middleware + super end
def build_request(env)
def build_request(env) req = super env["ORIGINAL_FULLPATH"] = req.fullpath env["ORIGINAL_SCRIPT_NAME"] = req.script_name req end
def config #:nodoc:
def config #:nodoc: @config ||= Application::Configuration.new(self.class.find_root(self.class.called_from)) end
def config=(configuration) #:nodoc:
def config=(configuration) #:nodoc: @config = configuration end
def config_for(name, env: Rails.env)
config.middleware.use ExceptionNotifier, config_for(:exception_notification)
Rails.application.configure do
# config/environments/production.rb
namespace: my_app_development
url: http://localhost:3001
development:
namespace: my_app_production
url: http://127.0.0.1:8080
production:
# config/exception_notification.yml:
Example:
Convenience for loading config/foo.yml for the current Rails env.
def config_for(name, env: Rails.env) if name.is_a?(Pathname) yaml = name else yaml = Pathname.new("#{paths["config"].existent.first}/#{name}.yml") end if yaml.exist? require "erb" (YAML.load(ERB.new(yaml.read).result) || {})[env] || {} else raise "Could not load configuration. No such file - #{yaml}" end rescue Psych::SyntaxError => e raise "YAML syntax error occurred while parsing #{yaml}. " \ "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \ "Error: #{e.message}" end
def console(&blk)
Sends any console called in the instance of a new application up
def console(&blk) self.class.console(&blk) end
def create(initial_variable_values = {}, &block)
def create(initial_variable_values = {}, &block) new(initial_variable_values, &block).run_load_hooks! end
def default_middleware_stack #:nodoc:
def default_middleware_stack #:nodoc: default_stack = DefaultMiddlewareStack.new(self, config, paths) default_stack.build_stack end
def env_config
Stores some of the Rails initial environment parameters which
def env_config @app_env_config ||= begin validate_secret_key_config! super.merge( "action_dispatch.parameter_filter" => config.filter_parameters, "action_dispatch.redirect_filter" => config.filter_redirect, "action_dispatch.secret_token" => secrets.secret_token, "action_dispatch.secret_key_base" => secrets.secret_key_base, "action_dispatch.show_exceptions" => config.action_dispatch.show_exceptions, "action_dispatch.show_detailed_exceptions" => config.consider_all_requests_local, "action_dispatch.logger" => Rails.logger, "action_dispatch.backtrace_cleaner" => Rails.backtrace_cleaner, "action_dispatch.key_generator" => key_generator, "action_dispatch.http_auth_salt" => config.action_dispatch.http_auth_salt, "action_dispatch.signed_cookie_salt" => config.action_dispatch.signed_cookie_salt, "action_dispatch.encrypted_cookie_salt" => config.action_dispatch.encrypted_cookie_salt, "action_dispatch.encrypted_signed_cookie_salt" => config.action_dispatch.encrypted_signed_cookie_salt, "action_dispatch.cookies_serializer" => config.action_dispatch.cookies_serializer, "action_dispatch.cookies_digest" => config.action_dispatch.cookies_digest ) end end
def find_root(from)
def find_root(from) find_root_with_flag "config.ru", from, Dir.pwd end
def generators(&blk)
Sends any generators called in the instance of a new application up
def generators(&blk) self.class.generators(&blk) end
def helpers_paths #:nodoc:
def helpers_paths #:nodoc: config.helpers_paths end
def inherited(base)
def inherited(base) super Rails.app_class = base add_lib_to_load_path!(find_root(base.called_from)) end
def initialize(initial_variable_values = {}, &block)
def initialize(initial_variable_values = {}, &block) super() @initialized = false @reloaders = [] @routes_reloader = nil @app_env_config = nil @ordered_railties = nil @railties = nil @message_verifiers = {} @ran_load_hooks = false @executor = Class.new(ActiveSupport::Executor) @reloader = Class.new(ActiveSupport::Reloader) @reloader.executor = @executor # are these actually used? @initial_variable_values = initial_variable_values @block = block end
def initialize!(group=:default) #:nodoc:
group is :default
Initialize the application passing the given group. By default, the
def initialize!(group=:default) #:nodoc: raise "Application has been already initialized." if @initialized run_initializers(group, self) @initialized = true self end
def initialized?
def initialized? @initialized end
def initializer(name, opts={}, &block)
Rails::Initializable module. Each Rails::Application class has its own
Sends the initializers to the +initializer+ method defined in the
def initializer(name, opts={}, &block) self.class.initializer(name, opts, &block) end
def initializers #:nodoc:
def initializers #:nodoc: Bootstrap.initializers_for(self) + railties_initializers(super) + Finisher.initializers_for(self) end
def instance
def instance super.run_load_hooks! end
def isolate_namespace(mod)
def isolate_namespace(mod) self.class.isolate_namespace(mod) end
def key_generator
def key_generator # number of iterations selected based on consultation with the google security # team. Details at https://github.com/rails/rails/pull/6952#issuecomment-7661220 @caching_key_generator ||= if secrets.secret_key_base unless secrets.secret_key_base.kind_of?(String) raise ArgumentError, "`secret_key_base` for #{Rails.env} environment must be a type of String, change this value in `config/secrets.yml`" end key_generator = ActiveSupport::KeyGenerator.new(secrets.secret_key_base, iterations: 1000) ActiveSupport::CachingKeyGenerator.new(key_generator) else ActiveSupport::LegacyKeyGenerator.new(secrets.secret_token) end end
def message_verifier(verifier_name)
# => 'my sensible data'
Rails.application.message_verifier('sensitive_data').verify(message)
message = Rails.application.message_verifier('sensitive_data').generate('my sensible data')
==== Examples
* +verifier_name+ - the name of the message verifier.
==== Parameters
verifiers passing the +verifier_name+ argument.
It is recommended not to use the same verifier for different things, so you can get different
This verifier can be used to generate and verify signed messages in the application.
Returns a message verifier object.
def message_verifier(verifier_name) @message_verifiers[verifier_name] ||= begin secret = key_generator.generate_key(verifier_name.to_s) ActiveSupport::MessageVerifier.new(secret) end end
def migration_railties # :nodoc:
+railties_order+.
copying migrations from railties ; we need them in the order given by
While running initializers we need engines in reverse order here when
and the order specified by the +railties_order+ config.
Return an array of railties respecting the order they're loaded
def migration_railties # :nodoc: ordered_railties.flatten - [self] end
def ordered_railties #:nodoc:
Returns the ordered railties for this application considering railties_order.
def ordered_railties #:nodoc: @ordered_railties ||= begin order = config.railties_order.map do |railtie| if railtie == :main_app self elsif railtie.respond_to?(:instance) railtie.instance else railtie end end all = (railties - order) all.push(self) unless (all + order).include?(self) order.push(:all) unless order.include?(:all) index = order.index(:all) order[index] = all order end end
def railties_initializers(current) #:nodoc:
def railties_initializers(current) #:nodoc: initializers = [] ordered_railties.reverse.flatten.each do |r| if r == self initializers += current else initializers += r.initializers end end initializers end
def rake_tasks(&block)
If you try to define a set of rake tasks on the instance, these will get
def rake_tasks(&block) self.class.rake_tasks(&block) end
def reload_routes!
def reload_routes! routes_reloader.reload! end
def require_environment! #:nodoc:
def require_environment! #:nodoc: environment = paths["config/environment"].existent.first require environment if environment end
def routes_reloader #:nodoc:
def routes_reloader #:nodoc: @routes_reloader ||= RoutesReloader.new end
def run_console_blocks(app) #:nodoc:
def run_console_blocks(app) #:nodoc: railties.each { |r| r.run_console_blocks(app) } super end
def run_generators_blocks(app) #:nodoc:
def run_generators_blocks(app) #:nodoc: railties.each { |r| r.run_generators_blocks(app) } super end
def run_load_hooks! # :nodoc:
def run_load_hooks! # :nodoc: return self if @ran_load_hooks @ran_load_hooks = true ActiveSupport.run_load_hooks(:before_configuration, self) @initial_variable_values.each do |variable_name, value| if INITIAL_VARIABLES.include?(variable_name) instance_variable_set("@#{variable_name}", value) end end instance_eval(&@block) if @block self end
def run_runner_blocks(app) #:nodoc:
def run_runner_blocks(app) #:nodoc: railties.each { |r| r.run_runner_blocks(app) } super end
def run_tasks_blocks(app) #:nodoc:
def run_tasks_blocks(app) #:nodoc: railties.each { |r| r.run_tasks_blocks(app) } super require "rails/tasks" task :environment do ActiveSupport.on_load(:before_initialize) { config.eager_load = false } require_environment! end end
def runner(&blk)
Sends any runner called in the instance of a new application up
def runner(&blk) self.class.runner(&blk) end
def secrets
+Rails.application.secrets.namespace+ returns +my_app_production+ in the
namespace: my_app_production
secret_key_base: <%= ENV["SECRET_KEY_BASE"] %>
production:
secret_key_base: 5a37811464e7d378488b0f073e2193b093682e4e21f5d6f3ae0a4e1781e61a351fdc878a843424e81c73fb484a40d23f92c8dafac4870e74ede6e5e174423010
test:
secret_key_base: 836fa3665997a860728bcb9e9a1e704d427cfc920e79d847d79c8a9a907b9e965defa4154b2b86bdec6930adbe33f21364523a6f6ce363865724549fdfc08553
development:
Example:
Returns secrets added to config/secrets.yml.
def secrets @secrets ||= begin secrets = ActiveSupport::OrderedOptions.new yaml = config.paths["config/secrets"].first if File.exist?(yaml) require "erb" all_secrets = YAML.load(ERB.new(IO.read(yaml)).result) || {} env_secrets = all_secrets[Rails.env] secrets.merge!(env_secrets.symbolize_keys) if env_secrets end # Fallback to config.secret_key_base if secrets.secret_key_base isn't set secrets.secret_key_base ||= config.secret_key_base # Fallback to config.secret_token if secrets.secret_token isn't set secrets.secret_token ||= config.secret_token secrets end end
def secrets=(secrets) #:nodoc:
def secrets=(secrets) #:nodoc: @secrets = secrets end
def to_app #:nodoc:
def to_app #:nodoc: self end
def validate_secret_key_config! #:nodoc:
def validate_secret_key_config! #:nodoc: if secrets.secret_key_base.blank? ActiveSupport::Deprecation.warn "You didn't set `secret_key_base`. " + "Read the upgrade documentation to learn more about this new config option." if secrets.secret_token.blank? raise "Missing `secret_key_base` for '#{Rails.env}' environment, set this value in `config/secrets.yml`" end end end
def watchable_args #:nodoc:
API.
directories-extensions suitable for ActiveSupport::FileUpdateChecker
Returns an array of file paths appended with a hash of
def watchable_args #:nodoc: files, dirs = config.watchable_files.dup, config.watchable_dirs.dup ActiveSupport::Dependencies.autoload_paths.each do |path| dirs[path.to_s] = [:rb] end [files, dirs] end