Class: ActionController::Parameters

Inherits:
Object
  • Object
show all
Defined in:
lib/action_controller/metal/strong_parameters.rb

Overview

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 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            # => #<ActionController::Parameters {"name"=>"Francesco", "age"=>22} permitted: true>
permitted.permitted? # => true

Person.first.update!(permitted)
# => #<Person id: 1, name: "Francesco", age: 22, role: "user">

It provides two options that controls the top-level behavior of new instances:

  • permit_all_parameters - If it’s true, all the parameters will be permitted by default. The default is false.

  • 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 an ActiveSupport::Notifications.instrument event on the unpermitted_parameters.action_controller topic and log at the DEBUG level.

    • :raise to raise an ActionController::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"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parameters = {}, logging_context = {}) ⇒ Parameters

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">


241
242
243
244
245
246
247
248
249
250
251
# File 'lib/action_controller/metal/strong_parameters.rb', line 241

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

Class Method Details

.hook_into_yaml_loadingObject

:nodoc:



891
892
893
894
895
896
897
# File 'lib/action_controller/metal/strong_parameters.rb', line 891

def self.hook_into_yaml_loading # :nodoc:
  # Wire up YAML format compatibility with Rails 4.2 and Psych 2.0.8 and 2.0.9+.
  # Makes the YAML parser call `init_with` when it encounters the keys below
  # instead of trying its own parsing routines.
  YAML.load_tags["!ruby/hash-with-ivars:ActionController::Parameters"] = name
  YAML.load_tags["!ruby/hash:ActionController::Parameters"] = name
end

.nested_attribute?(key, value) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)


220
221
222
# File 'lib/action_controller/metal/strong_parameters.rb', line 220

def nested_attribute?(key, value) # :nodoc:
  /\A-?\d+\z/.match?(key) && (value.is_a?(Hash) || value.is_a?(Parameters))
end

Instance Method Details

#==(other) ⇒ Object

Returns true if another Parameters object contains the same content and permitted flag.



255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
# File 'lib/action_controller/metal/strong_parameters.rb', line 255

def ==(other)
  if other.respond_to?(:permitted?)
    permitted? == other.permitted? && parameters == other.parameters
  else
    if self.class.allow_deprecated_parameters_hash_equality && Hash === other
      ActionController.deprecator.warn <<-WARNING.squish
        Comparing equality between `ActionController::Parameters` and a
        `Hash` is deprecated and will be removed in Rails 7.2. Please only do
        comparisons between instances of `ActionController::Parameters`. If
        you need to compare to a hash, first convert it using
        `ActionController::Parameters#new`.
        To disable the deprecated behavior set
        `Rails.application.config.action_controller.allow_deprecated_parameters_hash_equality = false`.
      WARNING
      @parameters == other
    else
      super
    end
  end
end

#[](key) ⇒ Object

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


637
638
639
# File 'lib/action_controller/metal/strong_parameters.rb', line 637

def [](key)
  convert_hashes_to_parameters(key, @parameters[key])
end

#[]=(key, value) ⇒ Object

Assigns a value to a given key. The given key may still get filtered out when #permit is called.



643
644
645
# File 'lib/action_controller/metal/strong_parameters.rb', line 643

def []=(key, value)
  @parameters[key] = value
end

#compactObject

Returns a new ActionController::Parameters instance with nil values removed.



814
815
816
# File 'lib/action_controller/metal/strong_parameters.rb', line 814

def compact
  new_instance_with_inherited_permitted_status(@parameters.compact)
end

#compact!Object

Removes all nil values in place and returns self, or nil if no changes were made.



819
820
821
# File 'lib/action_controller/metal/strong_parameters.rb', line 819

def compact!
  self if @parameters.compact!
end

#compact_blankObject

Returns a new ActionController::Parameters instance without the blank values. Uses Object#blank? for determining if a value is blank.



825
826
827
# File 'lib/action_controller/metal/strong_parameters.rb', line 825

def compact_blank
  reject { |_k, v| v.blank? }
end

#compact_blank!Object

Removes all blank values in place and returns self. Uses Object#blank? for determining if a value is blank.



831
832
833
# File 'lib/action_controller/metal/strong_parameters.rb', line 831

def compact_blank!
  reject! { |_k, v| v.blank? }
end

#converted_arraysObject

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.



402
403
404
# File 'lib/action_controller/metal/strong_parameters.rb', line 402

def converted_arrays
  @converted_arrays ||= Set.new
end

#deep_dupObject

Returns a duplicate ActionController::Parameters instance with the same permitted parameters.



923
924
925
926
927
# File 'lib/action_controller/metal/strong_parameters.rb', line 923

def deep_dup
  self.class.new(@parameters.deep_dup, @logging_context).tap do |duplicate|
    duplicate.permitted = @permitted
  end
end

#deep_transform_keys(&block) ⇒ Object

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.



765
766
767
768
769
# File 'lib/action_controller/metal/strong_parameters.rb', line 765

def deep_transform_keys(&block)
  new_instance_with_inherited_permitted_status(
    @parameters.deep_transform_keys(&block)
  )
end

#deep_transform_keys!(&block) ⇒ Object

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.



774
775
776
777
# File 'lib/action_controller/metal/strong_parameters.rb', line 774

def deep_transform_keys!(&block)
  @parameters.deep_transform_keys!(&block)
  self
end

#delete(key, &block) ⇒ Object

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.



783
784
785
# File 'lib/action_controller/metal/strong_parameters.rb', line 783

def delete(key, &block)
  convert_value_to_parameters(@parameters.delete(key, &block))
end

#dig(*keys) ⇒ Object

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


681
682
683
684
# File 'lib/action_controller/metal/strong_parameters.rb', line 681

def dig(*keys)
  convert_hashes_to_parameters(keys.first, @parameters[keys.first])
  @parameters.dig(*keys)
end

#each_pair(&block) ⇒ Object Also known as: each

Convert all hashes in values into parameters, then yield each pair in the same way as Hash#each_pair.



369
370
371
372
373
374
375
376
# File 'lib/action_controller/metal/strong_parameters.rb', line 369

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

#each_value(&block) ⇒ Object

Convert all hashes in values into parameters, then yield each value in the same way as Hash#each_value.



381
382
383
384
385
386
387
388
# File 'lib/action_controller/metal/strong_parameters.rb', line 381

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

#encode_with(coder) ⇒ Object

:nodoc:



918
919
920
# File 'lib/action_controller/metal/strong_parameters.rb', line 918

def encode_with(coder) # :nodoc:
  coder.map = { "parameters" => @parameters, "permitted" => @permitted }
end

#eql?(other) ⇒ Boolean

Returns:

  • (Boolean)


276
277
278
279
280
# File 'lib/action_controller/metal/strong_parameters.rb', line 276

def eql?(other)
  self.class == other.class &&
    permitted? == other.permitted? &&
    parameters.eql?(other.parameters)
end

#except(*keys) ⇒ Object Also known as: without

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>


710
711
712
# File 'lib/action_controller/metal/strong_parameters.rb', line 710

def except(*keys)
  new_instance_with_inherited_permitted_status(@parameters.except(*keys))
end

#extract!(*keys) ⇒ Object

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>


720
721
722
# File 'lib/action_controller/metal/strong_parameters.rb', line 720

def extract!(*keys)
  new_instance_with_inherited_permitted_status(@parameters.extract!(*keys))
end

#extract_value(key, delimiter: "_") ⇒ Object

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


935
936
937
# File 'lib/action_controller/metal/strong_parameters.rb', line 935

def extract_value(key, delimiter: "_")
  @parameters[key]&.split(delimiter)
end

#fetch(key, *args) ⇒ Object

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: none
params.fetch(:none, {})             # => #<ActionController::Parameters {} permitted: false>
params.fetch(:none, "Francesco")    # => "Francesco"
params.fetch(:none) { "Francesco" } # => "Francesco"


660
661
662
663
664
665
666
667
668
669
670
# File 'lib/action_controller/metal/strong_parameters.rb', line 660

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

#has_value?(value) ⇒ Boolean Also known as: value?

Returns true if the given value is present for some key in the parameters.

Returns:

  • (Boolean)


836
837
838
# File 'lib/action_controller/metal/strong_parameters.rb', line 836

def has_value?(value)
  each_value.include?(convert_value_to_parameters(value))
end

#hashObject



282
283
284
# File 'lib/action_controller/metal/strong_parameters.rb', line 282

def hash
  [self.class, @parameters, @permitted].hash
end

#init_with(coder) ⇒ Object

:nodoc:



900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
# File 'lib/action_controller/metal/strong_parameters.rb', line 900

def init_with(coder) # :nodoc:
  case coder.tag
  when "!ruby/hash:ActionController::Parameters"
    # YAML 2.0.8's format where hash instance variables weren't stored.
    @parameters = coder.map.with_indifferent_access
    @permitted  = false
  when "!ruby/hash-with-ivars:ActionController::Parameters"
    # YAML 2.0.9's Hash subclass format where keys and values
    # were stored under an elements hash and `permitted` within an ivars hash.
    @parameters = coder.map["elements"].with_indifferent_access
    @permitted  = coder.map["ivars"][:@permitted]
  when "!ruby/object:ActionController::Parameters"
    # YAML's Object format. Only needed because of the format
    # backwards compatibility above, otherwise equivalent to YAML's initialization.
    @parameters, @permitted = coder.map["parameters"], coder.map["permitted"]
  end
end

#inspectObject



887
888
889
# File 'lib/action_controller/metal/strong_parameters.rb', line 887

def inspect
  "#<#{self.class} #{@parameters} permitted: #{@permitted}>"
end

#keysObject

:method: to_s

:call-seq:

to_s()

Returns the content of the parameters as a string.



201
202
# File 'lib/action_controller/metal/strong_parameters.rb', line 201

delegate :keys, :empty?, :exclude?, :include?,
:as_json, :to_s, :each_key, to: :@parameters

#merge(other_hash) ⇒ Object

Returns a new ActionController::Parameters instance with all keys from other_hash merged into current hash.



850
851
852
853
854
# File 'lib/action_controller/metal/strong_parameters.rb', line 850

def merge(other_hash)
  new_instance_with_inherited_permitted_status(
    @parameters.merge(other_hash.to_h)
  )
end

#merge!(other_hash) ⇒ Object

Returns the current ActionController::Parameters instance with other_hash merged into current hash.



858
859
860
861
# File 'lib/action_controller/metal/strong_parameters.rb', line 858

def merge!(other_hash)
  @parameters.merge!(other_hash.to_h)
  self
end

#permit(*filters) ⇒ Object

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(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

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, 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 permitted.

params = ActionController::Parameters.new({
  person: {
    contact: {
      email: "none@test.com",
      phone: "555-1234"
    }
  }
})

params.require(:person).permit(:contact)
# => #<ActionController::Parameters {} permitted: true>

params.require(:person).permit(contact: :phone)
# => #<ActionController::Parameters {"contact"=>#<ActionController::Parameters {"phone"=>"555-1234"} permitted: true>} permitted: true>

params.require(:person).permit(contact: [ :email, :phone ])
# => #<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"}}}


614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
# File 'lib/action_controller/metal/strong_parameters.rb', line 614

def permit(*filters)
  params = self.class.new

  filters.flatten.each do |filter|
    case filter
    when Symbol, String
      permitted_scalar_filter(params, filter)
    when Hash
      hash_filter(params, filter)
    end
  end

  unpermitted_parameters!(params) if self.class.action_on_unpermitted_parameters

  params.permit!
end

#permit!Object

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">


428
429
430
431
432
433
434
435
436
437
# File 'lib/action_controller/metal/strong_parameters.rb', line 428

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

#permitted?Boolean

Returns true if the parameter is permitted, false otherwise.

params = ActionController::Parameters.new
params.permitted? # => false
params.permit!
params.permitted? # => true

Returns:

  • (Boolean)


412
413
414
# File 'lib/action_controller/metal/strong_parameters.rb', line 412

def permitted?
  @permitted
end

#reject(&block) ⇒ Object

Returns a new ActionController::Parameters instance with items that the block evaluates to true removed.



802
803
804
# File 'lib/action_controller/metal/strong_parameters.rb', line 802

def reject(&block)
  new_instance_with_inherited_permitted_status(@parameters.reject(&block))
end

#reject!(&block) ⇒ Object Also known as: delete_if

Removes items that the block evaluates to true and returns self.



807
808
809
810
# File 'lib/action_controller/metal/strong_parameters.rb', line 807

def reject!(&block)
  @parameters.reject!(&block)
  self
end

#require(key) ⇒ Object Also known as: required

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: person

ActionController::Parameters.new(person: nil).require(:person)
# ActionController::ParameterMissing: param is missing or the value is empty: person

ActionController::Parameters.new(person: "\t").require(:person)
# ActionController::ParameterMissing: param is missing or the value is empty: person

ActionController::Parameters.new(person: {}).require(:person)
# ActionController::ParameterMissing: param is missing or the value is empty: 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: user

Technically this method can be used to fetch terminal values:

# CAREFUL
params = ActionController::Parameters.new(person: { name: "Finn" })
name = params.require(:person).require(:name) # CAREFUL

but take into account that at some point those ones have to be permitted:

def person_params
  params.require(:person).permit(:name).tap do |person_params|
    person_params.require(:name) # SAFER
  end
end

for example.



489
490
491
492
493
494
495
496
497
# File 'lib/action_controller/metal/strong_parameters.rb', line 489

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

#reverse_merge(other_hash) ⇒ Object Also known as: with_defaults

Returns a new ActionController::Parameters instance with all keys from current hash merged into other_hash.



865
866
867
868
869
# File 'lib/action_controller/metal/strong_parameters.rb', line 865

def reverse_merge(other_hash)
  new_instance_with_inherited_permitted_status(
    other_hash.to_h.merge(@parameters)
  )
end

#reverse_merge!(other_hash) ⇒ Object Also known as: with_defaults!

Returns the current ActionController::Parameters instance with current hash merged into other_hash.



874
875
876
877
# File 'lib/action_controller/metal/strong_parameters.rb', line 874

def reverse_merge!(other_hash)
  @parameters.merge!(other_hash.to_h) { |key, left, right| left }
  self
end

#select(&block) ⇒ Object

Returns a new ActionController::Parameters instance with only items that the block evaluates to true.



789
790
791
# File 'lib/action_controller/metal/strong_parameters.rb', line 789

def select(&block)
  new_instance_with_inherited_permitted_status(@parameters.select(&block))
end

#select!(&block) ⇒ Object Also known as: keep_if

Equivalent to Hash#keep_if, but returns nil if no changes were made.



794
795
796
797
# File 'lib/action_controller/metal/strong_parameters.rb', line 794

def select!(&block)
  @parameters.select!(&block)
  self
end

#slice(*keys) ⇒ Object

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>


693
694
695
# File 'lib/action_controller/metal/strong_parameters.rb', line 693

def slice(*keys)
  new_instance_with_inherited_permitted_status(@parameters.slice(*keys))
end

#slice!(*keys) ⇒ Object

Returns the current ActionController::Parameters instance which contains only the given keys.



699
700
701
702
# File 'lib/action_controller/metal/strong_parameters.rb', line 699

def slice!(*keys)
  @parameters.slice!(*keys)
  self
end

#stringify_keysObject

This is required by ActiveModel attribute assignment, so that user can pass Parameters to a mass assignment methods in a model. It should not matter as we are using HashWithIndifferentAccess internally.



883
884
885
# File 'lib/action_controller/metal/strong_parameters.rb', line 883

def stringify_keys # :nodoc:
  dup
end

#to_h(&block) ⇒ Object

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"}


298
299
300
301
302
303
304
# File 'lib/action_controller/metal/strong_parameters.rb', line 298

def to_h(&block)
  if permitted?
    convert_parameters_to_hashes(@parameters, :to_h, &block)
  else
    raise UnfilteredParameters
  end
end

#to_hashObject

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"}


318
319
320
# File 'lib/action_controller/metal/strong_parameters.rb', line 318

def to_hash
  to_h.to_hash
end

#to_query(*args) ⇒ Object Also known as: to_param

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.



348
349
350
# File 'lib/action_controller/metal/strong_parameters.rb', line 348

def to_query(*args)
  to_h.to_query(*args)
end

#to_unsafe_hObject Also known as: to_unsafe_hash

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"}


362
363
364
# File 'lib/action_controller/metal/strong_parameters.rb', line 362

def to_unsafe_h
  convert_parameters_to_hashes(@parameters, :to_unsafe_h)
end

#transform_keys(&block) ⇒ Object

Returns a new ActionController::Parameters instance with the results of running block once for every key. The values are unchanged.



747
748
749
750
751
752
# File 'lib/action_controller/metal/strong_parameters.rb', line 747

def transform_keys(&block)
  return to_enum(:transform_keys) unless block_given?
  new_instance_with_inherited_permitted_status(
    @parameters.transform_keys(&block)
  )
end

#transform_keys!(&block) ⇒ Object

Performs keys transformation and returns the altered ActionController::Parameters instance.



756
757
758
759
760
# File 'lib/action_controller/metal/strong_parameters.rb', line 756

def transform_keys!(&block)
  return to_enum(:transform_keys!) unless block_given?
  @parameters.transform_keys!(&block)
  self
end

#transform_valuesObject

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>


730
731
732
733
734
735
# File 'lib/action_controller/metal/strong_parameters.rb', line 730

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

#transform_values!Object

Performs values transformation and returns the altered ActionController::Parameters instance.



739
740
741
742
743
# File 'lib/action_controller/metal/strong_parameters.rb', line 739

def transform_values!
  return to_enum(:transform_values!) unless block_given?
  @parameters.transform_values! { |v| yield convert_value_to_parameters(v) }
  self
end

#valuesObject

Returns a new array of the values of the parameters.



391
392
393
# File 'lib/action_controller/metal/strong_parameters.rb', line 391

def values
  to_enum(:each_value).to_a
end

#values_at(*keys) ⇒ Object

Returns values that were assigned to the given keys. Note that all the Hash objects will be converted to ActionController::Parameters.



844
845
846
# File 'lib/action_controller/metal/strong_parameters.rb', line 844

def values_at(*keys)
  convert_value_to_parameters(@parameters.values_at(*keys))
end