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# frozen_string_literal: true
require "active_support/concern"
require "active_support/ordered_options"
require "active_support/core_ext/array/extract_options"
module ActiveSupport
# Configurable provides a <tt>config</tt> method to store and retrieve
# configuration options as an <tt>OrderedHash</tt>.
module Configurable
extend ActiveSupport::Concern
class Configuration < ActiveSupport::InheritableOptions
def compile_methods!
self.class.compile_methods!(keys)
end
# Compiles reader methods so we don't have to go through method_missing.
def self.compile_methods!(keys)
keys.reject { |m| method_defined?(m) }.each do |key|
class_eval <<-RUBY, __FILE__, __LINE__ + 1
def #{key}; _get(#{key.inspect}); end
RUBY
end
end
end
module ClassMethods
def config
@_config ||= if respond_to?(:superclass) && superclass.respond_to?(:config)
superclass.config.inheritable_copy
else
# create a new "anonymous" class that will host the compiled reader methods
Class.new(Configuration).new
end
end
def configure
yield config
end
# Allows you to add shortcut so that you don't have to refer to attribute
# through config. Also look at the example for config to contrast.
#
# Defines both class and instance config accessors.
#
# class User
# include ActiveSupport::Configurable
# config_accessor :allowed_access
# end
#
# User.allowed_access # => nil
# User.allowed_access = false
# User.allowed_access # => false
#
# user = User.new
# user.allowed_access # => false
# user.allowed_access = true
# user.allowed_access # => true
#
# User.allowed_access # => false
#
# The attribute name must be a valid method name in Ruby.
#
# class User
# include ActiveSupport::Configurable
# config_accessor :"1_Badname"
# end
# # => NameError: invalid config attribute name
#
# To opt out of the instance writer method, pass <tt>instance_writer: false</tt>.
# To opt out of the instance reader method, pass <tt>instance_reader: false</tt>.
#
# class User
# include ActiveSupport::Configurable
# config_accessor :allowed_access, instance_reader: false, instance_writer: false
# end
#
# User.allowed_access = false
# User.allowed_access # => false
#
# User.new.allowed_access = true # => NoMethodError
# User.new.allowed_access # => NoMethodError
#
# Or pass <tt>instance_accessor: false</tt>, to opt out both instance methods.
#
# class User
# include ActiveSupport::Configurable
# config_accessor :allowed_access, instance_accessor: false
# end
#
# User.allowed_access = false
# User.allowed_access # => false
#
# User.new.allowed_access = true # => NoMethodError
# User.new.allowed_access # => NoMethodError
#
# Also you can pass a block to set up the attribute with a default value.
#
# class User
# include ActiveSupport::Configurable
# config_accessor :hair_colors do
# [:brown, :black, :blonde, :red]
# end
# end
#
# User.hair_colors # => [:brown, :black, :blonde, :red]
def config_accessor(*names)
options = names.extract_options!
names.each do |name|
raise NameError.new("invalid config attribute name") unless /\A[_A-Za-z]\w*\z/.match?(name)
reader, reader_line = "def #{name}; config.#{name}; end", __LINE__
writer, writer_line = "def #{name}=(value); config.#{name} = value; end", __LINE__
singleton_class.class_eval reader, __FILE__, reader_line
singleton_class.class_eval writer, __FILE__, writer_line
unless options[:instance_accessor] == false
class_eval reader, __FILE__, reader_line unless options[:instance_reader] == false
class_eval writer, __FILE__, writer_line unless options[:instance_writer] == false
end
send("#{name}=", yield) if block_given?
end
end
private :config_accessor
end
# Reads and writes attributes from a configuration <tt>OrderedHash</tt>.
#
# require 'active_support/configurable'
#
# class User
# include ActiveSupport::Configurable
# end
#
# user = User.new
#
# user.config.allowed_access = true
# user.config.level = 1
#
# user.config.allowed_access # => true
# user.config.level # => 1
def config
@_config ||= self.class.config.inheritable_copy
end
end
end
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