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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
module Hashie
class CoercionError < StandardError
def initialize(key, value, into, message)
super("Cannot coerce property #{key.inspect} from #{value.class} to #{into}: #{message}")
end
end
module Extensions
module Coercion
CORE_TYPES = {
Integer => :to_i,
Float => :to_f,
Complex => :to_c,
Rational => :to_r,
String => :to_s,
Symbol => :to_sym
}.freeze
ABSTRACT_CORE_TYPES =
{ Numeric => [Integer, Float, Complex, Rational] }
def self.included(base)
base.send :include, InstanceMethods
base.extend ClassMethods
unless base.method_defined?(:set_value_without_coercion)
base.send :alias_method, :set_value_without_coercion, :[]=
end
base.send :alias_method, :[]=, :set_value_with_coercion
end
module InstanceMethods
def set_value_with_coercion(key, value)
into = self.class.key_coercion(key) || self.class.value_coercion(value)
unless value.nil? || into.nil?
begin
value = self.class.fetch_coercion(into).call(value)
rescue NoMethodError, TypeError => e
raise CoercionError.new(key, value, into, e.message)
end
end
set_value_without_coercion(key, value)
end
def custom_writer(key, value, _convert = true)
self[key] = value
end
def replace(other_hash)
(keys - other_hash.keys).each { |key| delete(key) }
other_hash.each { |key, value| self[key] = value }
self
end
end
module ClassMethods
attr_writer :key_coercions
protected :key_coercions=
# Set up a coercion rule such that any time the specified
# key is set it will be coerced into the specified class.
# Coercion will occur by first attempting to call Class.coerce
# and then by calling Class.new with the value as an argument
# in either case.
#
# @param [Object] key the key or array of keys you would like to be coerced.
# @param [Class] into the class into which you want the key(s) coerced.
#
# @example Coerce a "user" subhash into a User object
# class Tweet < Hash
# include Hashie::Extensions::Coercion
# coerce_key :user, User
# end
def coerce_key(*attrs)
into = attrs.pop
attrs.each { |key| key_coercions[key] = into }
end
alias coerce_keys coerce_key
# Returns a hash of any existing key coercions.
def key_coercions
@key_coercions ||= {}
end
# Returns the specific key coercion for the specified key,
# if one exists.
def key_coercion(key)
key_coercions[key.to_sym]
end
# Set up a coercion rule such that any time a value of the
# specified type is set it will be coerced into the specified
# class.
#
# @param [Class] from the type you would like coerced.
# @param [Class] into the class into which you would like the value coerced.
# @option options [Boolean] :strict (true) whether use exact source class
# only or include ancestors
#
# @example Coerce all hashes into this special type of hash
# class SpecialHash < Hash
# include Hashie::Extensions::Coercion
# coerce_value Hash, SpecialHash
#
# def initialize(hash = {})
# super
# hash.each_pair do |k,v|
# self[k] = v
# end
# end
# end
def coerce_value(from, into, options = {})
options = { strict: true }.merge(options)
if ABSTRACT_CORE_TYPES.key? from
ABSTRACT_CORE_TYPES[from].each do |type|
coerce_value type, into, options
end
end
if options[:strict]
strict_value_coercions[from] = into
else
while from.superclass && from.superclass != Object
lenient_value_coercions[from] = into
from = from.superclass
end
end
end
# Return all value coercions that have the :strict rule as true.
def strict_value_coercions
@strict_value_coercions ||= {}
end
# Return all value coercions that have the :strict rule as false.
def lenient_value_coercions
@lenient_value_coercions ||= {}
end
# Fetch the value coercion, if any, for the specified object.
def value_coercion(value)
from = value.class
strict_value_coercions[from] || lenient_value_coercions[from]
end
def fetch_coercion(type)
return type if type.is_a? Proc
coercion_cache[type]
end
def coercion_cache
@coercion_cache ||= ::Hash.new do |hash, type|
hash[type] = build_coercion(type)
end
end
def build_coercion(type)
if type.is_a? Enumerable
if type.class == ::Hash
type, key_type, value_type = type.class, *type.first
build_hash_coercion(type, key_type, value_type)
else
value_type = type.first
type = type.class
build_container_coercion(type, value_type)
end
elsif CORE_TYPES.key? type
build_core_type_coercion(type)
elsif type.respond_to? :coerce
lambda do |value|
return value if value.is_a? type
type.coerce(value)
end
elsif type.respond_to? :new
lambda do |value|
return value if value.is_a? type
type.new(value)
end
else
raise TypeError, "#{type} is not a coercable type"
end
end
def build_hash_coercion(type, key_type, value_type)
key_coerce = fetch_coercion(key_type)
value_coerce = fetch_coercion(value_type)
lambda do |value|
type[value.map { |k, v| [key_coerce.call(k), value_coerce.call(v)] }]
end
end
def build_container_coercion(type, value_type)
value_coerce = fetch_coercion(value_type)
lambda do |value|
type.new(value.map { |v| value_coerce.call(v) })
end
end
def build_core_type_coercion(type)
name = CORE_TYPES[type]
lambda do |value|
return value if value.is_a? type
return value.send(name)
end
end
def inherited(klass)
super
klass.key_coercions = key_coercions.dup
end
end
end
end
end
|
