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rails--rails/railties/lib/rails/plugin/loader.rb

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require "rails/plugin"
module Rails
class Plugin
class Loader
attr_reader :initializer
# Creates a new Plugin::Loader instance, associated with the given
# Rails::Initializer. This default implementation automatically locates
# all plugins, and adds all plugin load paths, when it is created. The plugins
# are then fully loaded (init.rb is evaluated) when load_plugins is called.
#
# It is the loader's responsibility to ensure that only the plugins specified
# in the configuration are actually loaded, and that the order defined
# is respected.
def initialize(initializer)
@initializer = initializer
end
# Returns the plugins to be loaded, in the order they should be loaded.
def plugins
@plugins ||= all_plugins.select { |plugin| should_load?(plugin) }.sort { |p1, p2| order_plugins(p1, p2) }
end
# Returns the plugins that are in engine-form (have an app/ directory)
def engines
@engines ||= plugins.select(&:engine?)
end
# Returns all the plugins that could be found by the current locators.
def all_plugins
@all_plugins ||= locate_plugins
@all_plugins
end
def load_plugins
plugins.each do |plugin|
plugin.load(initializer)
register_plugin_as_loaded(plugin)
end
configure_engines
ensure_all_registered_plugins_are_loaded!
end
# Adds the load paths for every plugin into the $LOAD_PATH. Plugin load paths are
# added *after* the application's <tt>lib</tt> directory, to ensure that an application
# can always override code within a plugin.
#
# Plugin load paths are also added to Dependencies.load_paths, and Dependencies.load_once_paths.
def add_plugin_load_paths
plugins.each do |plugin|
plugin.load_paths.each do |path|
$LOAD_PATH.insert(application_lib_index + 1, path)
ActiveSupport::Dependencies.load_paths << path
unless configuration.reload_plugins?
ActiveSupport::Dependencies.load_once_paths << path
end
end
end
$LOAD_PATH.uniq!
end
def engine_metal_paths
engines.collect(&:metal_path)
end
protected
def configure_engines
if engines.any?
add_engine_routing_configurations
add_engine_controller_paths
add_engine_view_paths
end
end
def add_engine_routing_configurations
engines.select(&:routed?).collect(&:routing_file).each do |routing_file|
ActionController::Routing::Routes.add_configuration_file(routing_file)
end
end
def add_engine_controller_paths
ActionController::Routing.controller_paths += engines.collect(&:controller_path)
end
def add_engine_view_paths
# reverse it such that the last engine can overwrite view paths from the first, like with routes
paths = ActionView::PathSet.new(engines.collect(&:view_path).reverse)
ActionController::Base.view_paths.concat(paths)
ActionMailer::Base.view_paths.concat(paths) if configuration.frameworks.include?(:action_mailer)
end
# The locate_plugins method uses each class in config.plugin_locators to
# find the set of all plugins available to this Rails application.
def locate_plugins
configuration.plugin_locators.map do |locator|
locator.new(initializer).plugins
end.flatten
# TODO: sorting based on config.plugins
end
def register_plugin_as_loaded(plugin)
initializer.loaded_plugins << plugin
end
def configuration
initializer.configuration
end
def should_load?(plugin)
# uses Plugin#name and Plugin#valid?
enabled?(plugin) && plugin.valid?
end
def order_plugins(plugin_a, plugin_b)
if !explicit_plugin_loading_order?
plugin_a <=> plugin_b
else
if !explicitly_enabled?(plugin_a) && !explicitly_enabled?(plugin_b)
plugin_a <=> plugin_b
else
effective_order_of(plugin_a) <=> effective_order_of(plugin_b)
end
end
end
def effective_order_of(plugin)
if explicitly_enabled?(plugin)
registered_plugin_names.index(plugin.name)
else
registered_plugin_names.index('all')
end
end
def application_lib_index
$LOAD_PATH.index(File.join(RAILS_ROOT, 'lib')) || 0
end
def enabled?(plugin)
!explicit_plugin_loading_order? || registered?(plugin)
end
def explicit_plugin_loading_order?
!registered_plugin_names.nil?
end
def registered?(plugin)
explicit_plugin_loading_order? && registered_plugins_names_plugin?(plugin)
end
def explicitly_enabled?(plugin)
!explicit_plugin_loading_order? || explicitly_registered?(plugin)
end
def explicitly_registered?(plugin)
explicit_plugin_loading_order? && registered_plugin_names.include?(plugin.name)
end
def registered_plugins_names_plugin?(plugin)
registered_plugin_names.include?(plugin.name) || registered_plugin_names.include?('all')
end
# The plugins that have been explicitly listed with config.plugins. If this list is nil
# then it means the client does not care which plugins or in what order they are loaded,
# so we load all in alphabetical order. If it is an empty array, we load no plugins, if it is
# non empty, we load the named plugins in the order specified.
def registered_plugin_names
configuration.plugins ? configuration.plugins.map(&:to_s) : nil
end
def loaded?(plugin_name)
initializer.loaded_plugins.detect { |plugin| plugin.name == plugin_name.to_s }
end
def ensure_all_registered_plugins_are_loaded!
if explicit_plugin_loading_order?
if configuration.plugins.detect {|plugin| plugin != :all && !loaded?(plugin) }
missing_plugins = configuration.plugins - (plugins.map{|p| p.name.to_sym} + [:all])
raise LoadError, "Could not locate the following plugins: #{missing_plugins.to_sentence(:locale => :en)}"
end
end
end
end
end
end