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

124 lines
3.5 KiB
Ruby

module Rails
module Plugin
class Loader
include Comparable
attr_reader :initializer, :directory, :name
class << self
def load(*args)
new(*args).load
end
end
def initialize(initializer, directory)
@initializer = initializer
@directory = directory
@name = File.basename(directory)
end
def load
return false if loaded?
report_nonexistant_or_empty_plugin!
add_to_load_path!
register_plugin_as_loaded
evaluate
true
end
def loaded?
initializer.loaded_plugins.include?(name)
end
def plugin_path?
File.directory?(directory) && (has_lib_directory? || has_init_file?)
end
def enabled?
!explicit_plugin_loading_order? || registered?
end
def registered?
explicit_plugin_loading_order? && registered_plugins.include?(name)
end
def plugin_does_not_exist!(plugin_name = name)
raise LoadError, "Can not find the plugin named: #{plugin_name}"
end
private
# 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_plugins
config.plugins
end
def explicit_plugin_loading_order?
!registered_plugins.nil?
end
def report_nonexistant_or_empty_plugin!
plugin_does_not_exist! unless plugin_path?
end
def lib_path
File.join(directory, 'lib')
end
def init_path
File.join(directory, 'init.rb')
end
def has_lib_directory?
File.directory?(lib_path)
end
def has_init_file?
File.file?(init_path)
end
def add_to_load_path!
# Add lib to load path *after* the application lib, to allow
# application libraries to override plugin libraries.
if has_lib_directory?
application_lib_index = $LOAD_PATH.index(application_library_path) || 0
$LOAD_PATH.insert(application_lib_index + 1, lib_path)
Dependencies.load_paths << lib_path
Dependencies.load_once_paths << lib_path
end
end
def application_library_path
File.join(RAILS_ROOT, 'lib')
end
# Allow plugins to reference the current configuration object
def config
initializer.configuration
end
def register_plugin_as_loaded
initializer.loaded_plugins << name
end
# Evaluate in init.rb
def evaluate
silence_warnings { eval(IO.read(init_path), binding, init_path)} if has_init_file?
end
def <=>(other_plugin_loader)
if explicit_plugin_loading_order?
if non_existent_plugin = [self, other_plugin_loader].detect {|plugin| !registered_plugins.include?(plugin.name)}
plugin_does_not_exist!(non_existent_plugin.name)
end
registered_plugins.index(name) <=> registered_plugins.index(other_plugin_loader.name)
else
name <=> other_plugin_loader.name
end
end
end
end
end