1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
# 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) #:doc:
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
|
