Class: Rails::Initializer

Inherits:
Object show all
Defined in:
lib/initializer.rb

Overview

The Initializer is responsible for processing the Rails configuration, such as setting the $LOAD_PATH, requiring the right frameworks, initializing logging, and more. It can be run either as a single command that’ll just use the default configuration, like this:

Rails::Initializer.run

But normally it’s more interesting to pass in a custom configuration through the block running:

Rails::Initializer.run do |config|
  config.frameworks -= [ :action_web_service ]
end

This will use the default configuration options from Rails::Configuration, but allow for overwriting on select areas.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(configuration) ⇒ Initializer

Create a new Initializer instance that references the given Configuration instance.



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# File 'lib/initializer.rb', line 49

def initialize(configuration)
  @configuration = configuration
  @loaded_plugins = []
end

Instance Attribute Details

#configuration ⇒ Object (readonly)

The Configuration instance used by this Initializer instance.



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# File 'lib/initializer.rb', line 27

def configuration
  @configuration
end

#loaded_plugins ⇒ Object (readonly)

The set of loaded plugins.



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# File 'lib/initializer.rb', line 30

def loaded_plugins
  @loaded_plugins
end

Class Method Details

.run(command = :process, configuration = Configuration.new) {|configuration| ... } ⇒ Object

Runs the initializer. By default, this will invoke the #process method, which simply executes all of the initialization routines. Alternately, you can specify explicitly which initialization routine you want:

Rails::Initializer.run(:set_load_path)

This is useful if you only want the load path initialized, without incuring the overhead of completely loading the entire environment.

Yields:



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# File 'lib/initializer.rb', line 40

def self.run(command = :process, configuration = Configuration.new)
  yield configuration if block_given?
  initializer = new configuration
  initializer.send(command)
  initializer
end

Instance Method Details

#add_support_load_paths ⇒ Object

Add the load paths used by support functions such as the info controller



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# File 'lib/initializer.rb', line 166

def add_support_load_paths
end

#after_initialize ⇒ Object

Fires the user-supplied after_initialize block (Configuration#after_initialize)



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# File 'lib/initializer.rb', line 334

def after_initialize
  configuration.after_initialize_block.call if configuration.after_initialize_block
end

#check_ruby_version ⇒ Object

Check for valid Ruby version This is done in an external file, so we can use it from the ‘rails` program as well without duplication.



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# File 'lib/initializer.rb', line 120

def check_ruby_version
  require 'ruby_version_check'
end

#initialize_breakpoints ⇒ Object

Sets the BREAKPOINT_SERVER_PORT if Configuration#breakpoint_server is true.



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# File 'lib/initializer.rb', line 298

def initialize_breakpoints
  silence_warnings { Object.const_set("BREAKPOINT_SERVER_PORT", 42531) if configuration.breakpoint_server }
end

#initialize_database ⇒ Object

This initialization routine does nothing unless :active_record is one of the frameworks to load (Configuration#frameworks). If it is, this sets the database configuration from Configuration#database_configuration and then establishes the connection.



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# File 'lib/initializer.rb', line 226

def initialize_database
  return unless configuration.frameworks.include?(:active_record)
  ActiveRecord::Base.configurations = configuration.database_configuration
  ActiveRecord::Base.establish_connection
end

#initialize_dependency_mechanism ⇒ Object

Sets the dependency loading mechanism based on the value of Configuration#cache_classes.



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# File 'lib/initializer.rb', line 292

def initialize_dependency_mechanism
  Dependencies.mechanism = configuration.cache_classes ? :require : :load
end

#initialize_encoding ⇒ Object

This initialzation sets $KCODE to ‘u’ to enable the multibyte safe operations. Plugin authors supporting other encodings should override this behaviour and set the relevant default_charset on ActionController::Base



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# File 'lib/initializer.rb', line 218

def initialize_encoding
  $KCODE='u'
end

#initialize_framework_logging ⇒ Object

Sets the logger for ActiveRecord, ActionController, and ActionMailer (but only for those frameworks that are to be loaded). If the framework’s logger is already set, it is not changed, otherwise it is set to use RAILS_DEFAULT_LOGGER.



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# File 'lib/initializer.rb', line 265

def initialize_framework_logging
  for framework in ([ :active_record, :action_controller, :action_mailer ] & configuration.frameworks)
    framework.to_s.camelize.constantize.const_get("Base").logger ||= RAILS_DEFAULT_LOGGER
  end
end

#initialize_framework_settings ⇒ Object

Initializes framework-specific settings for each of the loaded frameworks (Configuration#frameworks). The available settings map to the accessors on each of the corresponding Base classes.



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# File 'lib/initializer.rb', line 323

def initialize_framework_settings
  configuration.frameworks.each do |framework|
    base_class = framework.to_s.camelize.constantize.const_get("Base")

    configuration.send(framework).each do |setting, value|
      base_class.send("#{setting}=", value)
    end
  end
end

#initialize_framework_views ⇒ Object

Sets the template_root for ActionController::Base and ActionMailer::Base (but only for those frameworks that are to be loaded). If the framework’s template_root has already been set, it is not changed, otherwise it is set to use Configuration#view_path.



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# File 'lib/initializer.rb', line 275

def initialize_framework_views
  for framework in ([ :action_controller, :action_mailer ] & configuration.frameworks)
    framework.to_s.camelize.constantize.const_get("Base").template_root ||= configuration.view_path
  end
end

#initialize_logger ⇒ Object

If the RAILS_DEFAULT_LOGGER constant is already set, this initialization routine does nothing. If the constant is not set, and Configuration#logger is not nil, this also does nothing. Otherwise, a new logger instance is created at Configuration#log_path, with a default log level of Configuration#log_level.

If the log could not be created, the log will be set to output to STDERR, with a log level of WARN.



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# File 'lib/initializer.rb', line 240

def initialize_logger
  # if the environment has explicitly defined a logger, use it
  return if defined?(RAILS_DEFAULT_LOGGER)

  unless logger = configuration.logger
    begin
      logger = Logger.new(configuration.log_path)
      logger.level = Logger.const_get(configuration.log_level.to_s.upcase)
    rescue StandardError
      logger = Logger.new(STDERR)
      logger.level = Logger::WARN
      logger.warn(
        "Rails Error: Unable to access log file. Please ensure that #{configuration.log_path} exists and is chmod 0666. " +
        "The log level has been raised to WARN and the output directed to STDERR until the problem is fixed."
      )
    end
  end

  silence_warnings { Object.const_set "RAILS_DEFAULT_LOGGER", logger }
end

#initialize_routing ⇒ Object

If ActionController is not one of the loaded frameworks (Configuration#frameworks) this does nothing. Otherwise, it loads the routing definitions and sets up loading module used to lazily load controllers (Configuration#controller_paths).



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# File 'lib/initializer.rb', line 284

def initialize_routing
  return unless configuration.frameworks.include?(:action_controller)
  ActionController::Routing.controller_paths = configuration.controller_paths
  ActionController::Routing::Routes.reload
end

#initialize_temporary_directories ⇒ Object 



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# File 'lib/initializer.rb', line 308

def initialize_temporary_directories
  if configuration.frameworks.include?(:action_controller)
    session_path = "#{RAILS_ROOT}/tmp/sessions/"
    ActionController::Base.session_options[:tmpdir] = File.exist?(session_path) ? session_path : Dir::tmpdir

    cache_path = "#{RAILS_ROOT}/tmp/cache/"
    if File.exist?(cache_path)
      ActionController::Base.fragment_cache_store = :file_store, cache_path
    end
  end
end

#initialize_whiny_nils ⇒ Object

Loads support for “whiny nil” (noisy warnings when methods are invoked on nil values) if Configuration#whiny_nils is true.



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# File 'lib/initializer.rb', line 304

def initialize_whiny_nils
  require('active_support/whiny_nil') if configuration.whiny_nils
end

#load_environment ⇒ Object

Loads the environment specified by Configuration#environment_path, which is typically one of development, testing, or production.



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# File 'lib/initializer.rb', line 200

def load_environment
  silence_warnings do
    config = configuration
    constants = self.class.constants
    eval(IO.read(configuration.environment_path), binding, configuration.environment_path)
    (self.class.constants - constants).each do |const|
      Object.const_set(const, self.class.const_get(const))
    end
  end
end

#load_observers ⇒ Object 



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# File 'lib/initializer.rb', line 211

def load_observers
  ActiveRecord::Base.instantiate_observers
end

#load_plugins ⇒ Object

Loads all plugins in config.plugin_paths. plugin_paths defaults to vendor/plugins but may also be set to a list of paths, such as

config.plugin_paths = ['lib/plugins', 'vendor/plugins']

Each plugin discovered in plugin_paths is initialized:

  • add its lib directory, if present, to the beginning of the load path

  • evaluate init.rb if present

After all plugins are loaded, duplicates are removed from the load path. If an array of plugin names is specified in config.plugins, the plugins will be loaded in that order. Otherwise, plugins are loaded in alphabetical order.



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# File 'lib/initializer.rb', line 182

def load_plugins
  if configuration.plugins.nil?
    # a nil value implies we don't care about plugins; load 'em all in a reliable order
    find_plugins(configuration.plugin_paths).sort.each { |path| load_plugin path }
  elsif !configuration.plugins.empty?
    # we've specified a config.plugins array, so respect that order
    plugin_paths = find_plugins(configuration.plugin_paths)
    configuration.plugins.each do |name|
      path = plugin_paths.find { |p| File.basename(p) == name }
      raise(LoadError, "Cannot find the plugin '#{name}'!") if path.nil?
      load_plugin path
    end
  end 
  $LOAD_PATH.uniq!
end

#process ⇒ Object

Sequentially step through all of the available initialization routines, in order:

  • #set_load_path

  • #set_connection_adapters

  • #require_frameworks

  • #load_environment

  • #initialize_database

  • #initialize_logger

  • #initialize_framework_logging

  • #initialize_framework_views

  • #initialize_dependency_mechanism

  • #initialize_breakpoints

  • #initialize_whiny_nils

  • #initialize_framework_settings

  • #load_environment

  • #load_plugins

  • #load_observers

  • #initialize_routing

(Note that #load_environment is invoked twice, once at the start and once at the end, to support the legacy configuration style where the environment could overwrite the defaults directly, instead of via the Configuration instance.



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# File 'lib/initializer.rb', line 78

def process
  check_ruby_version
  set_load_path
  set_connection_adapters

  require_frameworks
  set_autoload_paths
  load_environment

  initialize_encoding
  initialize_database
  initialize_logger
  initialize_framework_logging
  initialize_framework_views
  initialize_dependency_mechanism
  initialize_breakpoints
  initialize_whiny_nils
  initialize_temporary_directories
  initialize_framework_settings

  # Support for legacy configuration style where the environment
  # could overwrite anything set from the defaults/global through
  # the individual base class configurations.
  load_environment

  add_support_load_paths

  load_plugins

  # Observers are loaded after plugins in case Observers or observed models are modified by plugins.
  load_observers

  # Routing must be initialized after plugins to allow the former to extend the routes
  initialize_routing

  # the framework is now fully initialized
  after_initialize
end

#require_frameworks ⇒ Object

Requires all frameworks specified by the Configuration#frameworks list. By default, all frameworks (ActiveRecord, ActiveSupport, ActionPack, ActionMailer, and ActionWebService) are loaded.



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# File 'lib/initializer.rb', line 161

def require_frameworks
  configuration.frameworks.each { |framework| require(framework.to_s) }
end

#set_autoload_paths ⇒ Object

Set the paths from which Rails will automatically load source files, and the load_once paths.



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# File 'lib/initializer.rb', line 134

def set_autoload_paths
  Dependencies.load_paths = configuration.load_paths.uniq
  Dependencies.load_once_paths = configuration.load_once_paths.uniq

  extra = Dependencies.load_once_paths - Dependencies.load_paths
  unless extra.empty?
    abort <<-end_error
      load_once_paths must be a subset of the load_paths.
      Extra items in load_once_paths: #{extra * ','}
    end_error
  end

  # Freeze the arrays so future modifications will fail rather than do nothing mysteriously
  configuration.load_once_paths.freeze
end

#set_connection_adapters ⇒ Object

Sets the RAILS_CONNECTION_ADAPTERS constant based on the value of Configuration#connection_adapters. This constant is used to determine which database adapters should be loaded (by default, all adapters are loaded).



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# File 'lib/initializer.rb', line 154

def set_connection_adapters
  Object.const_set("RAILS_CONNECTION_ADAPTERS", configuration.connection_adapters) if configuration.connection_adapters
end

#set_load_path ⇒ Object

Set the $LOAD_PATH based on the value of Configuration#load_paths. Duplicates are removed.



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# File 'lib/initializer.rb', line 126

def set_load_path
  load_paths = configuration.load_paths + configuration.framework_paths
  load_paths.reverse_each { |dir| $LOAD_PATH.unshift(dir) if File.directory?(dir) }
  $LOAD_PATH.uniq!
end