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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
|
require 'active_support/concern'
require 'active_support/core_ext/hash/indifferent_access'
require 'active_support/rescuable'
module ActionController
# Raised when a required parameter is missing.
#
# params = ActionController::Parameters.new(a: {})
# params.fetch(:b)
# # => ActionController::ParameterMissing: param not found: b
# params.require(:a)
# # => ActionController::ParameterMissing: param not found: a
class ParameterMissing < KeyError
attr_reader :param # :nodoc:
def initialize(param) # :nodoc:
@param = param
super("param not found: #{param}")
end
end
# == Action Controller \Parameters
#
# Allows to choose which attributes should be whitelisted for mass updating
# and thus prevent accidentally exposing that which shouldn’t be exposed.
# Provides two methods for this purpose: #require and #permit. The former is
# used to mark parameters as required. The latter is used to set the parameter
# as permitted and limit which attributes should be allowed for mass updating.
#
# params = ActionController::Parameters.new({
# person: {
# name: 'Francesco',
# age: 22,
# role: 'admin'
# }
# })
#
# permitted = params.require(:person).permit(:name, :age)
# permitted # => {"name"=>"Francesco", "age"=>22}
# permitted.class # => ActionController::Parameters
# permitted.permitted? # => true
#
# Person.first.update_attributes!(permitted)
# # => #<Person id: 1, name: "Francesco", age: 22, role: "user">
#
# It provides a +permit_all_parameters+ option that controls the top-level
# behaviour of new instances. If it's +true+, all the parameters will be
# permitted by default. The default value for +permit_all_parameters+
# option is +false+.
#
# params = ActionController::Parameters.new
# params.permitted? # => false
#
# ActionController::Parameters.permit_all_parameters = true
#
# params = ActionController::Parameters.new
# params.permitted? # => true
#
# <tt>ActionController::Parameters</tt> is inherited from
# <tt>ActiveSupport::HashWithIndifferentAccess</tt>, this means
# that you can fetch values using either <tt>:key</tt> or <tt>"key"</tt>.
#
# params = ActionController::Parameters.new(key: 'value')
# params[:key] # => "value"
# params["key"] # => "value"
class Parameters < ActiveSupport::HashWithIndifferentAccess
cattr_accessor :permit_all_parameters, instance_accessor: false
attr_accessor :permitted # :nodoc:
# Returns a new instance of <tt>ActionController::Parameters</tt>.
# Also, sets the +permitted+ attribute to the default value of
# <tt>ActionController::Parameters.permit_all_parameters</tt>.
#
# class Person
# include ActiveRecord::Base
# end
#
# params = ActionController::Parameters.new(name: 'Francesco')
# params.permitted? # => false
# Person.new(params) # => ActiveModel::ForbiddenAttributesError
#
# ActionController::Parameters.permit_all_parameters = true
#
# params = ActionController::Parameters.new(name: 'Francesco')
# params.permitted? # => true
# Person.new(params) # => #<Person id: nil, name: "Francesco">
def initialize(attributes = nil)
super(attributes)
@permitted = self.class.permit_all_parameters
end
# Returns +true+ if the parameter is permitted, +false+ otherwise.
#
# params = ActionController::Parameters.new
# params.permitted? # => false
# params.permit!
# params.permitted? # => true
def permitted?
@permitted
end
# Sets the +permitted+ attribute to +true+. This can be used to pass
# mass assignment. Returns +self+.
#
# class Person < ActiveRecord::Base
# end
#
# params = ActionController::Parameters.new(name: 'Francesco')
# params.permitted? # => false
# Person.new(params) # => ActiveModel::ForbiddenAttributesError
# params.permit!
# params.permitted? # => true
# Person.new(params) # => #<Person id: nil, name: "Francesco">
def permit!
each_pair do |key, value|
convert_hashes_to_parameters(key, value)
self[key].permit! if self[key].respond_to? :permit!
end
@permitted = true
self
end
# Ensures that a parameter is present. If it's present, returns
# the parameter at the given +key+, otherwise raises an
# <tt>ActionController::ParameterMissing</tt> error.
#
# ActionController::Parameters.new(person: { name: 'Francesco' }).require(:person)
# # => {"name"=>"Francesco"}
#
# ActionController::Parameters.new(person: nil).require(:person)
# # => ActionController::ParameterMissing: param not found: person
#
# ActionController::Parameters.new(person: {}).require(:person)
# # => ActionController::ParameterMissing: param not found: person
def require(key)
self[key].presence || raise(ParameterMissing.new(key))
end
# Alias of #require.
alias :required :require
# Returns a new <tt>ActionController::Parameters</tt> instance that
# includes only the given +filters+ and sets the +permitted+ attribute
# for the object to +true+. This is useful for limiting which attributes
# should be allowed for mass updating.
#
# params = ActionController::Parameters.new(user: { name: 'Francesco', age: 22, role: 'admin' })
# permitted = params.require(:user).permit(:name, :age)
# permitted.permitted? # => true
# permitted.has_key?(:name) # => true
# permitted.has_key?(:age) # => true
# permitted.has_key?(:role) # => false
#
# You can also use +permit+ on nested parameters, like:
#
# params = ActionController::Parameters.new({
# person: {
# name: 'Francesco',
# age: 22,
# pets: [{
# name: 'Purplish',
# category: 'dogs'
# }]
# }
# })
#
# permitted = params.permit(person: [ :name, { pets: :name } ])
# permitted.permitted? # => true
# permitted[:person][:name] # => "Francesco"
# permitted[:person][:age] # => nil
# permitted[:person][:pets][0][:name] # => "Purplish"
# permitted[:person][:pets][0][:category] # => nil
#
# Note that if you use +permit+ in a key that points to a hash,
# it won't allow all the hash. You also need to specify which
# attributes inside the hash should be whitelisted.
#
# params = ActionController::Parameters.new({
# person: {
# contact: {
# email: 'none@test.com'
# phone: '555-1234'
# }
# }
# })
#
# params.require(:person).permit(:contact)
# # => {}
#
# params.require(:person).permit(contact: :phone)
# # => {"contact"=>{"phone"=>"555-1234"}}
#
# params.require(:person).permit(contact: [ :email, :phone ])
# # => {"contact"=>{"email"=>"none@test.com", "phone"=>"555-1234"}}
def permit(*filters)
params = self.class.new
filters.flatten.each do |filter|
case filter
when Symbol, String then
if has_key?(filter)
_value = self[filter]
params[filter] = _value unless Hash === _value
end
keys.grep(/\A#{Regexp.escape(filter)}\(\d+[if]?\)\z/) { |key| params[key] = self[key] }
when Hash then
self.slice(*filter.keys).each do |key, values|
return unless values
key = key.to_sym
params[key] = each_element(values) do |value|
# filters are a Hash, so we expect value to be a Hash too
next if filter.is_a?(Hash) && !value.is_a?(Hash)
value = self.class.new(value) if !value.respond_to?(:permit)
value.permit(*Array.wrap(filter[key]))
end
end
end
end
params.permit!
end
# Returns a parameter for the given +key+. If not found,
# returns +nil+.
#
# params = ActionController::Parameters.new(person: { name: 'Francesco' })
# params[:person] # => {"name"=>"Francesco"}
# params[:none] # => nil
def [](key)
convert_hashes_to_parameters(key, super)
end
# Returns a parameter for the given +key+. If the +key+
# can't be found, there are several options: With no other arguments,
# it will raise an <tt>ActionController::ParameterMissing</tt> error;
# if more arguments are given, then that will be returned; if a block
# is given, then that will be run and its result returned.
#
# params = ActionController::Parameters.new(person: { name: 'Francesco' })
# params.fetch(:person) # => {"name"=>"Francesco"}
# params.fetch(:none) # => ActionController::ParameterMissing: param not found: none
# params.fetch(:none, 'Francesco') # => "Francesco"
# params.fetch(:none) { 'Francesco' } # => "Francesco"
def fetch(key, *args)
convert_hashes_to_parameters(key, super)
rescue KeyError
raise ActionController::ParameterMissing.new(key)
end
# Returns a new <tt>ActionController::Parameters</tt> instance that
# includes only the given +keys+. If the given +keys+
# don't exist, returns an empty hash.
#
# params = ActionController::Parameters.new(a: 1, b: 2, c: 3)
# params.slice(:a, :b) # => {"a"=>1, "b"=>2}
# params.slice(:d) # => {}
def slice(*keys)
self.class.new(super)
end
# Returns an exact copy of the <tt>ActionController::Parameters</tt>
# instance. +permitted+ state is kept on the duped object.
#
# params = ActionController::Parameters.new(a: 1)
# params.permit!
# params.permitted? # => true
# copy_params = params.dup # => {"a"=>1}
# copy_params.permitted? # => true
def dup
super.tap do |duplicate|
duplicate.instance_variable_set :@permitted, @permitted
end
end
private
def convert_hashes_to_parameters(key, value)
if value.is_a?(Parameters) || !value.is_a?(Hash)
value
else
# Convert to Parameters on first access
self[key] = self.class.new(value)
end
end
def each_element(object)
if object.is_a?(Array)
object.map { |el| yield el }.compact
elsif object.is_a?(Hash) && object.keys.all? { |k| k =~ /\A-?\d+\z/ }
hash = object.class.new
object.each { |k,v| hash[k] = yield v }
hash
else
yield object
end
end
end
# == Strong \Parameters
#
# It provides an interface for protecting attributes from end-user
# assignment. This makes Action Controller parameters forbidden
# to be used in Active Model mass assignment until they have been
# whitelisted.
#
# In addition, parameters can be marked as required and flow through a
# predefined raise/rescue flow to end up as a 400 Bad Request with no
# effort.
#
# class PeopleController < ActionController::Base
# # Using "Person.create(params[:person])" would raise an
# # ActiveModel::ForbiddenAttributes exception because it'd
# # be using mass assignment without an explicit permit step.
# # This is the recommended form:
# def create
# Person.create(person_params)
# end
#
# # This will pass with flying colors as long as there's a person key in the
# # parameters, otherwise it'll raise an ActionController::MissingParameter
# # exception, which will get caught by ActionController::Base and turned
# # into a 400 Bad Request reply.
# def update
# redirect_to current_account.people.find(params[:id]).tap { |person|
# person.update_attributes!(person_params)
# }
# end
#
# private
# # Using a private method to encapsulate the permissible parameters is
# # just a good pattern since you'll be able to reuse the same permit
# # list between create and update. Also, you can specialize this method
# # with per-user checking of permissible attributes.
# def person_params
# params.require(:person).permit(:name, :age)
# end
# end
#
# In order to use <tt>accepts_nested_attribute_for</tt> with Strong \Parameters, you
# will need to specify which nested attributes should be whitelisted.
#
# class Person
# has_many :pets
# accepts_nested_attributes_for :pets
# end
#
# class PeopleController < ActionController::Base
# def create
# Person.create(person_params)
# end
#
# ...
#
# private
#
# def person_params
# # It's mandatory to specify the nested attributes that should be whitelisted.
# # If you use `permit` with just the key that points to the nested attributes hash,
# # it will return an empty hash.
# params.require(:person).permit(:name, :age, pets_attributes: [ :name, :category ])
# end
# end
#
# See ActionController::Parameters.require and ActionController::Parameters.permit
# for more information.
module StrongParameters
extend ActiveSupport::Concern
include ActiveSupport::Rescuable
included do
rescue_from(ActionController::ParameterMissing) do |parameter_missing_exception|
render text: "Required parameter missing: #{parameter_missing_exception.param}", status: :bad_request
end
end
# Returns a new ActionController::Parameters object that
# has been instantiated with the <tt>request.parameters</tt>.
def params
@_params ||= Parameters.new(request.parameters)
end
# Assigns the given +value+ to the +params+ hash. If +value+
# is a Hash, this will create an ActionController::Parameters
# object that has been instantiated with the given +value+ hash.
def params=(value)
@_params = value.is_a?(Hash) ? Parameters.new(value) : value
end
end
end
|