class ActionController::Parameters
Action Controller Parameters
¶ ↑
Allows you to choose which attributes should be permitted for mass updating and thus prevent accidentally exposing that which shouldn’t be exposed.
Provides methods for filtering and requiring params:
-
expect
to safely permit and require parameters in one step. -
permit
to filter params for mass assignment. -
require
to require a parameter or raise an error.
Examples:
params = ActionController::Parameters.new({ person: { name: "Francesco", age: 22, role: "admin" } }) permitted = params.expect(person: [:name, :age]) permitted # => #<ActionController::Parameters {"name"=>"Francesco", "age"=>22} permitted: true> Person.first.update!(permitted) # => #<Person id: 1, name: "Francesco", age: 22, role: "user">
Parameters
provides two options that control the top-level behavior of new instances:
-
permit_all_parameters
- If it’strue
, all the parameters will be permitted by default. The default isfalse
. -
action_on_unpermitted_parameters
- Controls behavior when parameters that are not explicitly permitted are found. The default value is:log
in test and development environments,false
otherwise. The values can be:-
false
to take no action. -
:log
to emit anActiveSupport::Notifications.instrument
event on theunpermitted_parameters.action_controller
topic and log at the DEBUG level. -
:raise
to raise anActionController::UnpermittedParameters
exception.
-
Examples:
params = ActionController::Parameters.new params.permitted? # => false ActionController::Parameters.permit_all_parameters = true params = ActionController::Parameters.new params.permitted? # => true params = ActionController::Parameters.new(a: "123", b: "456") params.permit(:c) # => #<ActionController::Parameters {} permitted: true> ActionController::Parameters.action_on_unpermitted_parameters = :raise params = ActionController::Parameters.new(a: "123", b: "456") params.permit(:c) # => ActionController::UnpermittedParameters: found unpermitted keys: a, b
Please note that these options are not thread-safe. In a multi-threaded environment they should only be set once at boot-time and never mutated at runtime.
You can fetch values of ActionController::Parameters
using either :key
or "key"
.
params = ActionController::Parameters.new(key: "value") params[:key] # => "value" params["key"] # => "value"
Constants
- PERMITTED_SCALAR_TYPES
— Filtering ———————————————————-
This is a list of permitted scalar types that includes the ones supported in XML and JSON requests.
This list is in particular used to filter ordinary requests, String goes as first element to quickly short-circuit the common case.
If you modify this collection please update the one in the
permit
doc as well.
Attributes
Public Class Methods
Returns a new ActionController::Parameters
instance. Also, sets the permitted
attribute to the default value of ActionController::Parameters.permit_all_parameters
.
class Person < 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">
# File lib/action_controller/metal/strong_parameters.rb, line 287 def initialize(parameters = {}, logging_context = {}) parameters.each_key do |key| unless key.is_a?(String) || key.is_a?(Symbol) raise InvalidParameterKey, "all keys must be Strings or Symbols, got: #{key.class}" end end @parameters = parameters.with_indifferent_access @logging_context = logging_context @permitted = self.class.permit_all_parameters end
Public Instance Methods
Returns true if another Parameters
object contains the same content and permitted flag.
# File lib/action_controller/metal/strong_parameters.rb, line 301 def ==(other) if other.respond_to?(:permitted?) permitted? == other.permitted? && parameters == other.parameters else super end end
Returns a parameter for the given key
. If not found, returns nil
.
params = ActionController::Parameters.new(person: { name: "Francesco" }) params[:person] # => #<ActionController::Parameters {"name"=>"Francesco"} permitted: false> params[:none] # => nil
# File lib/action_controller/metal/strong_parameters.rb, line 797 def [](key) convert_hashes_to_parameters(key, @parameters[key]) end
Assigns a value to a given key
. The given key may still get filtered out when permit
is called.
# File lib/action_controller/metal/strong_parameters.rb, line 803 def []=(key, value) @parameters[key] = value end
Returns a hash that can be used as the JSON representation for the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 194
Returns a new ActionController::Parameters
instance with nil
values removed.
# File lib/action_controller/metal/strong_parameters.rb, line 974 def compact new_instance_with_inherited_permitted_status(@parameters.compact) end
Removes all nil
values in place and returns self
, or nil
if no changes were made.
# File lib/action_controller/metal/strong_parameters.rb, line 980 def compact! self if @parameters.compact! end
Returns a new ActionController::Parameters
instance without the blank values. Uses Object#blank? for determining if a value is blank.
# File lib/action_controller/metal/strong_parameters.rb, line 986 def compact_blank reject { |_k, v| v.blank? } end
Removes all blank values in place and returns self. Uses Object#blank? for determining if a value is blank.
# File lib/action_controller/metal/strong_parameters.rb, line 992 def compact_blank! reject! { |_k, v| v.blank? } end
Attribute that keeps track of converted arrays, if any, to avoid double looping in the common use case permit + mass-assignment. Defined in a method to instantiate it only if needed.
Testing
membership still loops, but it’s going to be faster than our own loop that converts values. Also, we are not going to build a new array object per fetch.
# File lib/action_controller/metal/strong_parameters.rb, line 435 def converted_arrays @converted_arrays ||= Set.new end
Returns a duplicate ActionController::Parameters
instance with the same permitted parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 1092 def deep_dup self.class.new(@parameters.deep_dup, @logging_context).tap do |duplicate| duplicate.permitted = @permitted end end
Returns a new ActionController::Parameters
instance with self
and other_hash
merged recursively.
Like with Hash#merge
in the standard library, a block can be provided to merge values.
# File lib/action_controller/metal/strong_parameters.rb, line 168
Same as #deep_merge
, but modifies self
.
# File lib/action_controller/metal/strong_parameters.rb, line 183
Returns a new ActionController::Parameters
instance with the results of running block
once for every key. This includes the keys from the root hash and from all nested hashes and arrays. The values are unchanged.
# File lib/action_controller/metal/strong_parameters.rb, line 924 def deep_transform_keys(&block) new_instance_with_inherited_permitted_status( _deep_transform_keys_in_object(@parameters, &block).to_unsafe_h ) end
Returns the same ActionController::Parameters
instance with changed keys. This includes the keys from the root hash and from all nested hashes and arrays. The values are unchanged.
# File lib/action_controller/metal/strong_parameters.rb, line 933 def deep_transform_keys!(&block) @parameters = _deep_transform_keys_in_object(@parameters, &block).to_unsafe_h self end
Deletes a key-value pair from Parameters
and returns the value. If key
is not found, returns nil
(or, with optional code block, yields key
and returns the result). This method is similar to extract!
, which returns the corresponding ActionController::Parameters
object.
# File lib/action_controller/metal/strong_parameters.rb, line 942 def delete(key, &block) convert_value_to_parameters(@parameters.delete(key, &block)) end
Extracts the nested parameter from the given keys
by calling dig
at each step. Returns nil
if any intermediate step is nil
.
params = ActionController::Parameters.new(foo: { bar: { baz: 1 } }) params.dig(:foo, :bar, :baz) # => 1 params.dig(:foo, :zot, :xyz) # => nil params2 = ActionController::Parameters.new(foo: [10, 11, 12]) params2.dig(:foo, 1) # => 11
# File lib/action_controller/metal/strong_parameters.rb, line 841 def dig(*keys) convert_hashes_to_parameters(keys.first, @parameters[keys.first]) @parameters.dig(*keys) end
Calls block once for each key in the parameters, passing the key. If no block is given, an enumerator is returned instead.
# File lib/action_controller/metal/strong_parameters.rb, line 202
Convert all hashes in values into parameters, then yield each pair in the same way as Hash#each_pair
.
# File lib/action_controller/metal/strong_parameters.rb, line 402 def each_pair(&block) return to_enum(__callee__) unless block_given? @parameters.each_pair do |key, value| yield [key, convert_hashes_to_parameters(key, value)] end self end
Convert all hashes in values into parameters, then yield each value in the same way as Hash#each_value
.
# File lib/action_controller/metal/strong_parameters.rb, line 414 def each_value(&block) return to_enum(:each_value) unless block_given? @parameters.each_pair do |key, value| yield convert_hashes_to_parameters(key, value) end self end
Returns true if the parameters have no key/value pairs.
# File lib/action_controller/metal/strong_parameters.rb, line 211
# File lib/action_controller/metal/strong_parameters.rb, line 309 def eql?(other) self.class == other.class && permitted? == other.permitted? && parameters.eql?(other.parameters) end
Returns a new ActionController::Parameters
instance that filters out the given keys
.
params = ActionController::Parameters.new(a: 1, b: 2, c: 3) params.except(:a, :b) # => #<ActionController::Parameters {"c"=>3} permitted: false> params.except(:d) # => #<ActionController::Parameters {"a"=>1, "b"=>2, "c"=>3} permitted: false>
# File lib/action_controller/metal/strong_parameters.rb, line 869 def except(*keys) new_instance_with_inherited_permitted_status(@parameters.except(*keys)) end
Returns true if the given key is not present in the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 219
expect
is the preferred way to require and permit parameters. It is safer than the previous recommendation to call permit
and require
in sequence, which could allow user triggered 500 errors.
expect
is more strict with types to avoid a number of potential pitfalls that may be encountered with the .require.permit
pattern.
For example:
params = ActionController::Parameters.new(comment: { text: "hello" }) params.expect(comment: [:text]) # => #<ActionController::Parameters { text: "hello" } permitted: true> params = ActionController::Parameters.new(comment: [{ text: "hello" }, { text: "world" }]) params.expect(comment: [:text]) # => ActionController::ParameterMissing: param is missing or the value is empty or invalid: comment
In order to permit an array of parameters, the array must be defined explicitly. Use double array brackets, an array inside an array, to declare that an array of parameters is expected.
params = ActionController::Parameters.new(comments: [{ text: "hello" }, { text: "world" }]) params.expect(comments: [[:text]]) # => [#<ActionController::Parameters { "text" => "hello" } permitted: true>, # #<ActionController::Parameters { "text" => "world" } permitted: true>] params = ActionController::Parameters.new(comments: { text: "hello" }) params.expect(comments: [[:text]]) # => ActionController::ParameterMissing: param is missing or the value is empty or invalid: comments
expect
is intended to protect against array tampering.
params = ActionController::Parameters.new(user: "hack") # The previous way of requiring and permitting parameters will error params.require(:user).permit(:name, pets: [:name]) # wrong # => NoMethodError: undefined method `permit' for an instance of String # similarly with nested parameters params = ActionController::Parameters.new(user: { name: "Martin", pets: { name: "hack" } }) user_params = params.require(:user).permit(:name, pets: [:name]) # wrong # user_params[:pets] is expected to be an array but is a hash
expect
solves this by being more strict with types.
params = ActionController::Parameters.new(user: "hack") params.expect(user: [ :name, pets: [[:name]] ]) # => ActionController::ParameterMissing: param is missing or the value is empty or invalid: user # with nested parameters params = ActionController::Parameters.new(user: { name: "Martin", pets: { name: "hack" } }) user_params = params.expect(user: [:name, pets: [[:name]] ]) user_params[:pets] # => nil
As the examples show, expect
requires the :user
key, and any root keys similar to the .require.permit
pattern. If multiple root keys are expected, they will all be required.
params = ActionController::Parameters.new
(name: “Martin”, pies: [{ type: “dessert”, flavor: “pumpkin”}]) name, pies = params.expect(:name, pies: [[:type, :flavor]]) name # => “Martin” pies # => [#<ActionController::Parameters {“type”=>“dessert”, “flavor”=>“pumpkin”} permitted: true>]
When called with a hash with multiple keys, expect
will permit the parameters and require the keys in the order they are given in the hash, returning an array of the permitted parameters.
params = Besides being more strict about array vs hash params, An array of permitted scalars may be expected with the following:ActionController::Parameters.new
(subject: { name: “Martin” }, object: { pie: “pumpkin” }) subject, object = params.expect(subject: [:name], object: [:pie]) subject # => expect
uses permit internally, so it will behave similarly.params = ActionController::Parameters.new({
person: {
name: "Francesco",
age: 22,
pets: [{
name: "Purplish",
category: "dogs"
}]
}
})
permitted = params.expect(person: [ :name, { pets: [[:name]] } ])
permitted.permitted? # => true
permitted[:name] # => "Francesco"
permitted[:age] # => nil
permitted[:pets][0][:name] # => "Purplish"
permitted[:pets][0][:category] # => nil
params = ActionController::Parameters.new(tags: ["rails", "parameters"])
permitted = params.expect(tags: [])
permitted.permitted? # => true
permitted.is_a?(Array) # => true
permitted.size # => 2
# File lib/action_controller/metal/strong_parameters.rb, line 772
def expect(*filters)
params = permit_filters(filters)
keys = filters.flatten.flat_map { |f| f.is_a?(Hash) ? f.keys : f }
values = params.require(keys)
values.size == 1 ? values.first : values
end
Same as expect
, but raises an ActionController::ExpectedParameterMissing
instead of ActionController::ParameterMissing
. Unlike expect
which will render a 400 response, expect!
will raise an exception that is not handled. This is intended for debugging invalid params for an internal API
where incorrectly formatted params would indicate a bug in a client library that should be fixed.
# File lib/action_controller/metal/strong_parameters.rb, line 786 def expect!(*filters) expect(*filters) rescue ParameterMissing => e raise ExpectedParameterMissing.new(e.param, e.keys) end
Removes and returns the key/value pairs matching the given keys.
params = ActionController::Parameters.new(a: 1, b: 2, c: 3) params.extract!(:a, :b) # => #<ActionController::Parameters {"a"=>1, "b"=>2} permitted: false> params # => #<ActionController::Parameters {"c"=>3} permitted: false>
# File lib/action_controller/metal/strong_parameters.rb, line 879 def extract!(*keys) new_instance_with_inherited_permitted_status(@parameters.extract!(*keys)) end
Returns parameter value for the given key
separated by delimiter
.
params = ActionController::Parameters.new(id: "1_123", tags: "ruby,rails") params.extract_value(:id) # => ["1", "123"] params.extract_value(:tags, delimiter: ",") # => ["ruby", "rails"] params.extract_value(:non_existent_key) # => nil
Note that if the given key
‘s value contains blank elements, then the returned array will include empty strings.
params = ActionController::Parameters.new(tags: "ruby,rails,,web") params.extract_value(:tags, delimiter: ",") # => ["ruby", "rails", "", "web"]
# File lib/action_controller/metal/strong_parameters.rb, line 1110 def extract_value(key, delimiter: "_") @parameters[key]&.split(delimiter, -1) 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 ActionController::ParameterMissing
error; if a second argument is given, then that is returned (converted to an instance of ActionController::Parameters
if possible); if a block is given, then that will be run and its result returned.
params = ActionController::Parameters.new(person: { name: "Francesco" }) params.fetch(:person) # => #<ActionController::Parameters {"name"=>"Francesco"} permitted: false> params.fetch(:none) # => ActionController::ParameterMissing: param is missing or the value is empty or invalid: none params.fetch(:none, {}) # => #<ActionController::Parameters {} permitted: false> params.fetch(:none, "Francesco") # => "Francesco" params.fetch(:none) { "Francesco" } # => "Francesco"
# File lib/action_controller/metal/strong_parameters.rb, line 820 def fetch(key, *args) convert_value_to_parameters( @parameters.fetch(key) { if block_given? yield else args.fetch(0) { raise ActionController::ParameterMissing.new(key, @parameters.keys) } end } ) end
Returns true if the given value is present for some key in the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 997 def has_value?(value) each_value.include?(convert_value_to_parameters(value)) end
# File lib/action_controller/metal/strong_parameters.rb, line 315 def hash [self.class, @parameters, @permitted].hash end
Returns true if the given key is present in the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 227
# File lib/action_controller/metal/strong_parameters.rb, line 1055 def inspect "#<#{self.class} #{@parameters} permitted: #{@permitted}>" end
Returns a new array of the keys of the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 235
Returns a new ActionController::Parameters
instance with all keys from other_hash
merged into current hash.
# File lib/action_controller/metal/strong_parameters.rb, line 1011 def merge(other_hash) new_instance_with_inherited_permitted_status( @parameters.merge(other_hash.to_h) ) end
Returns the current ActionController::Parameters
instance with other_hash
merged into current hash.
# File lib/action_controller/metal/strong_parameters.rb, line 1022 def merge!(other_hash, &block) @parameters.merge!(other_hash.to_h, &block) self end
Returns a new ActionController::Parameters
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(name: "Francesco", age: 22, role: "admin") permitted = params.permit(:name, :age) permitted.permitted? # => true permitted.has_key?(:name) # => true permitted.has_key?(:age) # => true permitted.has_key?(:role) # => false
Only permitted scalars pass the filter. For example, given
params.permit(:name)
:name
passes if it is a key of params
whose associated value is of type String
, Symbol
, NilClass
, Numeric
, TrueClass
, FalseClass
, Date
, Time
, DateTime
, StringIO
, IO
, ActionDispatch::Http::UploadedFile
or Rack::Test::UploadedFile
. Otherwise, the key :name
is filtered out.
You may declare that the parameter should be an array of permitted scalars by mapping it to an empty array:
params = ActionController::Parameters.new(tags: ["rails", "parameters"]) params.permit(tags: [])
Sometimes it is not possible or convenient to declare the valid keys of a hash parameter or its internal structure. Just map to an empty hash:
params.permit(preferences: {})
Be careful because this opens the door to arbitrary input. In this case, permit
ensures values in the returned structure are permitted scalars and filters out anything else.
You can also use permit
on nested parameters:
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
This has the added benefit of rejecting user-modified inputs that send a string when a hash is expected.
When followed by require
, you can both filter and require parameters following the typical pattern of a Rails form. The expect
method was made specifically for this use case and is the recommended way to require and permit parameters.
permitted = params.expect(person: [:name, :age])
When using permit
and require
separately, pay careful attention to the order of the method calls.
params = ActionController::Parameters.new(person: { name: "Martin", age: 40, role: "admin" }) permitted = params.permit(person: [:name, :age]).require(:person) # correct
When require is used first, it is possible for users of your application to trigger a NoMethodError when the user, for example, sends a string for :person.
params = ActionController::Parameters.new(person: "tampered") permitted = params.require(:person).permit(:name, :age) # not recommended # => NoMethodError: undefined method `permit' for an instance of String
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 permitted.
params = ActionController::Parameters.new({ person: { contact: { email: "none@test.com", phone: "555-1234" } } }) params.permit(person: :contact).require(:person) # => #<ActionController::Parameters {} permitted: true> params.permit(person: { contact: :phone }).require(:person) # => #<ActionController::Parameters {"contact"=>#<ActionController::Parameters {"phone"=>"555-1234"} permitted: true>} permitted: true> params.permit(person: { contact: [ :email, :phone ] }).require(:person) # => #<ActionController::Parameters {"contact"=>#<ActionController::Parameters {"email"=>"none@test.com", "phone"=>"555-1234"} permitted: true>} permitted: true>
If your parameters specify multiple parameters indexed by a number, you can permit each set of parameters under the numeric key to be the same using the same syntax as permitting a single item.
params = ActionController::Parameters.new({ person: { '0': { email: "none@test.com", phone: "555-1234" }, '1': { email: "nothing@test.com", phone: "555-6789" }, } }) params.permit(person: [:email]).to_h # => {"person"=>{"0"=>{"email"=>"none@test.com"}, "1"=>{"email"=>"nothing@test.com"}}}
If you want to specify what keys you want from each numeric key, you can instead specify each one individually
params = ActionController::Parameters.new({ person: { '0': { email: "none@test.com", phone: "555-1234" }, '1': { email: "nothing@test.com", phone: "555-6789" }, } }) params.permit(person: { '0': [:email], '1': [:phone]}).to_h # => {"person"=>{"0"=>{"email"=>"none@test.com"}, "1"=>{"phone"=>"555-6789"}}}
# File lib/action_controller/metal/strong_parameters.rb, line 668 def permit(*filters) permit_filters(filters, on_unpermitted: self.class.action_on_unpermitted_parameters, explicit_arrays: false) 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">
# File lib/action_controller/metal/strong_parameters.rb, line 461 def permit! each_pair do |key, value| Array.wrap(value).flatten.each do |v| v.permit! if v.respond_to? :permit! end end @permitted = true self end
Returns true
if the parameter is permitted, false
otherwise.
params = ActionController::Parameters.new params.permitted? # => false params.permit! params.permitted? # => true
# File lib/action_controller/metal/strong_parameters.rb, line 445 def permitted? @permitted end
Returns a new ActionController::Parameters
instance with items that the block evaluates to true removed.
# File lib/action_controller/metal/strong_parameters.rb, line 961 def reject(&block) new_instance_with_inherited_permitted_status(@parameters.reject(&block)) end
Removes items that the block evaluates to true and returns self.
# File lib/action_controller/metal/strong_parameters.rb, line 966 def reject!(&block) @parameters.reject!(&block) self end
This method accepts both a single key and an array of keys.
When passed a single key, if it exists and its associated value is either present or the singleton false
, returns said value:
ActionController::Parameters.new(person: { name: "Francesco" }).require(:person) # => #<ActionController::Parameters {"name"=>"Francesco"} permitted: false>
Otherwise raises ActionController::ParameterMissing
:
ActionController::Parameters.new.require(:person) # ActionController::ParameterMissing: param is missing or the value is empty or invalid: person ActionController::Parameters.new(person: nil).require(:person) # ActionController::ParameterMissing: param is missing or the value is empty or invalid: person ActionController::Parameters.new(person: "\t").require(:person) # ActionController::ParameterMissing: param is missing or the value is empty or invalid: person ActionController::Parameters.new(person: {}).require(:person) # ActionController::ParameterMissing: param is missing or the value is empty or invalid: person
When given an array of keys, the method tries to require each one of them in order. If it succeeds, an array with the respective return values is returned:
params = ActionController::Parameters.new(user: { ... }, profile: { ... }) user_params, profile_params = params.require([:user, :profile])
Otherwise, the method re-raises the first exception found:
params = ActionController::Parameters.new(user: {}, profile: {}) user_params, profile_params = params.require([:user, :profile]) # ActionController::ParameterMissing: param is missing or the value is empty or invalid: user
This method is not recommended for fetching terminal values because it does not permit the values. For example, this can cause problems:
# CAREFUL params = ActionController::Parameters.new(person: { name: "Finn" }) name = params.require(:person).require(:name) # CAREFUL
It is recommended to use expect
instead:
def person_params # params.expect(person: :name).require(:name) end
# File lib/action_controller/metal/strong_parameters.rb, line 519 def require(key) return key.map { |k| require(k) } if key.is_a?(Array) value = self[key] if value.present? || value == false value else raise ParameterMissing.new(key, @parameters.keys) end end
Returns a new ActionController::Parameters
instance with all keys from current hash merged into other_hash
.
# File lib/action_controller/metal/strong_parameters.rb, line 1033 def reverse_merge(other_hash) new_instance_with_inherited_permitted_status( other_hash.to_h.merge(@parameters) ) end
Returns the current ActionController::Parameters
instance with current hash merged into other_hash
.
# File lib/action_controller/metal/strong_parameters.rb, line 1042 def reverse_merge!(other_hash) @parameters.merge!(other_hash.to_h) { |key, left, right| left } self end
Returns a new ActionController::Parameters
instance with only items that the block evaluates to true.
# File lib/action_controller/metal/strong_parameters.rb, line 948 def select(&block) new_instance_with_inherited_permitted_status(@parameters.select(&block)) end
Equivalent to Hash#keep_if, but returns nil
if no changes were made.
# File lib/action_controller/metal/strong_parameters.rb, line 953 def select!(&block) @parameters.select!(&block) self end
Returns a new ActionController::Parameters
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) # => #<ActionController::Parameters {"a"=>1, "b"=>2} permitted: false> params.slice(:d) # => #<ActionController::Parameters {} permitted: false>
# File lib/action_controller/metal/strong_parameters.rb, line 852 def slice(*keys) new_instance_with_inherited_permitted_status(@parameters.slice(*keys)) end
Returns the current ActionController::Parameters
instance which contains only the given keys
.
# File lib/action_controller/metal/strong_parameters.rb, line 858 def slice!(*keys) @parameters.slice!(*keys) self end
Returns a safe ActiveSupport::HashWithIndifferentAccess representation of the parameters with all unpermitted keys removed.
params = ActionController::Parameters.new({ name: "Senjougahara Hitagi", oddity: "Heavy stone crab" }) params.to_h # => ActionController::UnfilteredParameters: unable to convert unpermitted parameters to hash safe_params = params.permit(:name) safe_params.to_h # => {"name"=>"Senjougahara Hitagi"}
# File lib/action_controller/metal/strong_parameters.rb, line 331 def to_h(&block) if permitted? convert_parameters_to_hashes(@parameters, :to_h, &block) else raise UnfilteredParameters end end
Returns a safe Hash
representation of the parameters with all unpermitted keys removed.
params = ActionController::Parameters.new({ name: "Senjougahara Hitagi", oddity: "Heavy stone crab" }) params.to_hash # => ActionController::UnfilteredParameters: unable to convert unpermitted parameters to hash safe_params = params.permit(:name) safe_params.to_hash # => {"name"=>"Senjougahara Hitagi"}
# File lib/action_controller/metal/strong_parameters.rb, line 351 def to_hash to_h.to_hash end
Returns a string representation of the receiver suitable for use as a URL query string:
params = ActionController::Parameters.new({ name: "David", nationality: "Danish" }) params.to_query # => ActionController::UnfilteredParameters: unable to convert unpermitted parameters to hash safe_params = params.permit(:name, :nationality) safe_params.to_query # => "name=David&nationality=Danish"
An optional namespace can be passed to enclose key names:
params = ActionController::Parameters.new({ name: "David", nationality: "Danish" }) safe_params = params.permit(:name, :nationality) safe_params.to_query("user") # => "user%5Bname%5D=David&user%5Bnationality%5D=Danish"
The string pairs "key=value"
that conform the query string are sorted lexicographically in ascending order.
# File lib/action_controller/metal/strong_parameters.rb, line 381 def to_query(*args) to_h.to_query(*args) end
Returns the content of the parameters as a string.
# File lib/action_controller/metal/strong_parameters.rb, line 250 delegate :keys, :empty?, :exclude?, :include?, :as_json, :to_s, :each_key, to: :@parameters
Returns an unsafe, unfiltered ActiveSupport::HashWithIndifferentAccess representation of the parameters.
params = ActionController::Parameters.new({ name: "Senjougahara Hitagi", oddity: "Heavy stone crab" }) params.to_unsafe_h # => {"name"=>"Senjougahara Hitagi", "oddity" => "Heavy stone crab"}
# File lib/action_controller/metal/strong_parameters.rb, line 395 def to_unsafe_h convert_parameters_to_hashes(@parameters, :to_unsafe_h) end
Returns a new ActionController::Parameters
instance with the results of running block
once for every key. The values are unchanged.
# File lib/action_controller/metal/strong_parameters.rb, line 906 def transform_keys(&block) return to_enum(:transform_keys) unless block_given? new_instance_with_inherited_permitted_status( @parameters.transform_keys(&block) ) end
Performs keys transformation and returns the altered ActionController::Parameters
instance.
# File lib/action_controller/metal/strong_parameters.rb, line 915 def transform_keys!(&block) return to_enum(:transform_keys!) unless block_given? @parameters.transform_keys!(&block) self end
Returns a new ActionController::Parameters
instance with the results of running block
once for every value. The keys are unchanged.
params = ActionController::Parameters.new(a: 1, b: 2, c: 3) params.transform_values { |x| x * 2 } # => #<ActionController::Parameters {"a"=>2, "b"=>4, "c"=>6} permitted: false>
# File lib/action_controller/metal/strong_parameters.rb, line 889 def transform_values return to_enum(:transform_values) unless block_given? new_instance_with_inherited_permitted_status( @parameters.transform_values { |v| yield convert_value_to_parameters(v) } ) end
Performs values transformation and returns the altered ActionController::Parameters
instance.
# File lib/action_controller/metal/strong_parameters.rb, line 898 def transform_values! return to_enum(:transform_values!) unless block_given? @parameters.transform_values! { |v| yield convert_value_to_parameters(v) } self end
Returns a new array of the values of the parameters.
# File lib/action_controller/metal/strong_parameters.rb, line 424 def values to_enum(:each_value).to_a end
Returns values that were assigned to the given keys
. Note that all the Hash
objects will be converted to ActionController::Parameters
.
# File lib/action_controller/metal/strong_parameters.rb, line 1005 def values_at(*keys) convert_value_to_parameters(@parameters.values_at(*keys)) end
Protected Instance Methods
# File lib/action_controller/metal/strong_parameters.rb, line 1123 def each_nested_attribute hash = self.class.new self.each { |k, v| hash[k] = yield v if Parameters.nested_attribute?(k, v) } hash end
# File lib/action_controller/metal/strong_parameters.rb, line 1119 def nested_attributes? @parameters.any? { |k, v| Parameters.nested_attribute?(k, v) } end
Filters self and optionally checks for unpermitted keys
# File lib/action_controller/metal/strong_parameters.rb, line 1130 def permit_filters(filters, on_unpermitted: nil, explicit_arrays: true) params = self.class.new filters.flatten.each do |filter| case filter when Symbol, String # Declaration [:name, "age"] permitted_scalar_filter(params, filter) when Hash # Declaration [{ person: ... }] hash_filter(params, filter, on_unpermitted:, explicit_arrays:) end end unpermitted_parameters!(params, on_unpermitted:) params.permit! end
Private Instance Methods
# File lib/action_controller/metal/strong_parameters.rb, line 1192 def _deep_transform_keys_in_object(object, &block) case object when Hash object.each_with_object(self.class.new) do |(key, value), result| result[yield(key)] = _deep_transform_keys_in_object(value, &block) end when Parameters if object.permitted? object.to_h.deep_transform_keys(&block) else object.to_unsafe_h.deep_transform_keys(&block) end when Array object.map { |e| _deep_transform_keys_in_object(e, &block) } else object end end
# File lib/action_controller/metal/strong_parameters.rb, line 1211 def _deep_transform_keys_in_object!(object, &block) case object when Hash object.keys.each do |key| value = object.delete(key) object[yield(key)] = _deep_transform_keys_in_object!(value, &block) end object when Parameters if object.permitted? object.to_h.deep_transform_keys!(&block) else object.to_unsafe_h.deep_transform_keys!(&block) end when Array object.map! { |e| _deep_transform_keys_in_object!(e, &block) } else object end end
When an array is expected, you must specify an array explicitly using the following format:
params.expect(comments: [[:flavor]])
Which will match only the following array formats:
{ pies: [{ flavor: "rhubarb" }, { flavor: "apple" }] } { pies: { "0" => { flavor: "key lime" }, "1" => { flavor: "mince" } } }
When using permit
, arrays are specified the same way as hashes:
params.expect(pies: [:flavor])
In this case, permit
would also allow matching with a hash (or vice versa):
{ pies: { flavor: "cherry" } }
# File lib/action_controller/metal/strong_parameters.rb, line 1256 def array_filter?(filter) filter.is_a?(Array) && filter.size == 1 && filter.first.is_a?(Array) end
# File lib/action_controller/metal/strong_parameters.rb, line 1172 def convert_hashes_to_parameters(key, value) converted = convert_value_to_parameters(value) @parameters[key] = converted unless converted.equal?(value) converted end
# File lib/action_controller/metal/strong_parameters.rb, line 1156 def convert_parameters_to_hashes(value, using, &block) case value when Array value.map { |v| convert_parameters_to_hashes(v, using) } when Hash transformed = value.transform_values do |v| convert_parameters_to_hashes(v, using) end (block_given? ? transformed.to_h(&block) : transformed).with_indifferent_access when Parameters value.send(using) else value end end
# File lib/action_controller/metal/strong_parameters.rb, line 1178 def convert_value_to_parameters(value) case value when Array return value if converted_arrays.member?(value) converted = value.map { |_| convert_value_to_parameters(_) } converted_arrays << converted.dup converted when Hash self.class.new(value, @logging_context) else value end end
Called when an explicit array filter is encountered.
# File lib/action_controller/metal/strong_parameters.rb, line 1261 def each_array_element(object, filter, &block) case object when Array object.grep(Parameters).filter_map(&block) when Parameters if object.nested_attributes? && !specify_numeric_keys?(filter) object.each_nested_attribute(&block) end end end
# File lib/action_controller/metal/strong_parameters.rb, line 1352 def hash_filter(params, filter, on_unpermitted: self.class.action_on_unpermitted_parameters, explicit_arrays: false) filter = filter.with_indifferent_access # Slicing filters out non-declared keys. slice(*filter.keys).each do |key, value| next unless value next unless has_key? key result = permit_value(value, filter[key], on_unpermitted:, explicit_arrays:) params[key] = result unless result.nil? end end
# File lib/action_controller/metal/strong_parameters.rb, line 1437 def initialize_copy(source) super @parameters = @parameters.dup end
# File lib/action_controller/metal/strong_parameters.rb, line 1150 def new_instance_with_inherited_permitted_status(hash) self.class.new(hash, @logging_context).tap do |new_instance| new_instance.permitted = @permitted end end
# File lib/action_controller/metal/strong_parameters.rb, line 1346 def non_scalar?(value) value.is_a?(Array) || value.is_a?(Parameters) end
# File lib/action_controller/metal/strong_parameters.rb, line 1420 def permit_any_in_array(array) [].tap do |sanitized| array.each do |element| case element when ->(e) { permitted_scalar?(e) } sanitized << element when Array sanitized << permit_any_in_array(element) when Parameters sanitized << permit_any_in_parameters(element) else # Filter this one out. end end end end
# File lib/action_controller/metal/strong_parameters.rb, line 1403 def permit_any_in_parameters(params) self.class.new.tap do |sanitized| params.each do |key, value| case value when ->(v) { permitted_scalar?(v) } sanitized[key] = value when Array sanitized[key] = permit_any_in_array(value) when Parameters sanitized[key] = permit_any_in_parameters(value) else # Filter this one out. end end end end
# File lib/action_controller/metal/strong_parameters.rb, line 1382 def permit_array_of_hashes(value, filter, on_unpermitted:, explicit_arrays:) each_array_element(value, filter) do |element| element.permit_filters(Array.wrap(filter), on_unpermitted:, explicit_arrays:) end end
# File lib/action_controller/metal/strong_parameters.rb, line 1378 def permit_array_of_scalars(value) value if value.is_a?(Array) && value.all? { |element| permitted_scalar?(element) } end
# File lib/action_controller/metal/strong_parameters.rb, line 1388 def permit_hash(value, filter, on_unpermitted:, explicit_arrays:) return unless value.is_a?(Parameters) if filter == EMPTY_HASH permit_any_in_parameters(value) else value.permit_filters(Array.wrap(filter), on_unpermitted:, explicit_arrays:) end end
# File lib/action_controller/metal/strong_parameters.rb, line 1398 def permit_hash_or_array(value, filter, on_unpermitted:, explicit_arrays:) permit_array_of_hashes(value, filter, on_unpermitted:, explicit_arrays:) || permit_hash(value, filter, on_unpermitted:, explicit_arrays:) end
# File lib/action_controller/metal/strong_parameters.rb, line 1364 def permit_value(value, filter, on_unpermitted:, explicit_arrays:) if filter == EMPTY_ARRAY # Declaration { comment_ids: [] }. permit_array_of_scalars(value) elsif filter == EMPTY_HASH # Declaration { preferences: {} }. permit_hash(value, filter, on_unpermitted:, explicit_arrays:) elsif array_filter?(filter) # Declaration { comments: [[:text]] } permit_array_of_hashes(value, filter.first, on_unpermitted:, explicit_arrays:) elsif explicit_arrays # Declaration { user: { address: ... } } or { user: [:name, ...] } (only allows hash value) permit_hash(value, filter, on_unpermitted:, explicit_arrays:) elsif non_scalar?(value) # Declaration { user: { address: ... } } or { user: [:name, ...] } permit_hash_or_array(value, filter, on_unpermitted:, explicit_arrays:) end end
# File lib/action_controller/metal/strong_parameters.rb, line 1317 def permitted_scalar?(value) PERMITTED_SCALAR_TYPES.any? { |type| value.is_a?(type) } end
Adds existing keys to the params if their values are scalar.
For example:
puts self.keys #=> ["zipcode(90210i)"] params = {} permitted_scalar_filter(params, "zipcode") puts params.keys # => ["zipcode"]
# File lib/action_controller/metal/strong_parameters.rb, line 1331 def permitted_scalar_filter(params, permitted_key) permitted_key = permitted_key.to_s if has_key?(permitted_key) && permitted_scalar?(self[permitted_key]) params[permitted_key] = self[permitted_key] end each_key do |key| next unless key =~ /\(\d+[if]?\)\z/ next unless $~.pre_match == permitted_key params[key] = self[key] if permitted_scalar?(self[key]) end end
# File lib/action_controller/metal/strong_parameters.rb, line 1232 def specify_numeric_keys?(filter) if filter.respond_to?(:keys) filter.keys.any? { |key| /\A-?\d+\z/.match?(key) } end end
# File lib/action_controller/metal/strong_parameters.rb, line 1286 def unpermitted_keys(params) keys - params.keys - always_permitted_parameters end
# File lib/action_controller/metal/strong_parameters.rb, line 1272 def unpermitted_parameters!(params, on_unpermitted: self.class.action_on_unpermitted_parameters) return unless on_unpermitted unpermitted_keys = unpermitted_keys(params) if unpermitted_keys.any? case on_unpermitted when :log name = "unpermitted_parameters.action_controller" ActiveSupport::Notifications.instrument(name, keys: unpermitted_keys, context: @logging_context) when :raise raise ActionController::UnpermittedParameters.new(unpermitted_keys) end end end