require "active_support/core_ext/hash/indifferent_access"
require "active_support/core_ext/hash/transform_values"
require "active_support/core_ext/array/wrap"
require "active_support/core_ext/string/filters"
require "active_support/core_ext/object/to_query"
require "active_support/rescuable"
require "action_dispatch/http/upload"
require "rack/test"
require "stringio"
require "set"
require "yaml"
module ActionController
# Raised when a required parameter is missing.
#
# params = ActionController::Parameters.new(a: {})
# params.fetch(:b)
# # => ActionController::ParameterMissing: param is missing or the value is empty: b
# params.require(:a)
# # => ActionController::ParameterMissing: param is missing or the value is empty: a
class ParameterMissing < KeyError
attr_reader :param # :nodoc:
def initialize(param) # :nodoc:
@param = param
super("param is missing or the value is empty: #{param}")
end
end
# Raised when a supplied parameter is not expected and
# ActionController::Parameters.action_on_unpermitted_parameters
# is set to :raise.
#
# params = ActionController::Parameters.new(a: "123", b: "456")
# params.permit(:c)
# # => ActionController::UnpermittedParameters: found unpermitted parameters: :a, :b
class UnpermittedParameters < IndexError
attr_reader :params # :nodoc:
def initialize(params) # :nodoc:
@params = params
super("found unpermitted parameter#{'s' if params.size > 1 }: #{params.map { |e| ":#{e}" }.join(", ")}")
end
end
# == Action Controller \Parameters
#
# Allows you 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 # => "Francesco", "age"=>22} permitted: true>
# permitted.permitted? # => true
#
# Person.first.update!(permitted)
# # => #
#
# 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+ - Allow to control the behavior when parameters
# that are not explicitly permitted are found. The values can be :log to
# write a message on the logger or :raise to raise
# ActionController::UnpermittedParameters exception. The default value is :log
# in test and development environments, +false+ otherwise.
#
# 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.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 Parameters
cattr_accessor :permit_all_parameters, instance_accessor: false
self.permit_all_parameters = false
cattr_accessor :action_on_unpermitted_parameters, instance_accessor: false
delegate :keys, :key?, :has_key?, :values, :has_value?, :value?, :empty?, :include?,
:as_json, to: :@parameters
# By default, never raise an UnpermittedParameters exception if these
# params are present. The default includes both 'controller' and 'action'
# because they are added by Rails and should be of no concern. One way
# to change these is to specify `always_permitted_parameters` in your
# config. For instance:
#
# config.always_permitted_parameters = %w( controller action format )
cattr_accessor :always_permitted_parameters
self.always_permitted_parameters = %w( controller action )
# Returns a new instance of ActionController::Parameters.
# 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) # => #
def initialize(parameters = {})
@parameters = parameters.with_indifferent_access
@permitted = self.class.permit_all_parameters
end
# Returns true if another +Parameters+ object contains the same content and
# permitted flag.
def ==(other)
if other.respond_to?(:permitted?)
self.permitted? == other.permitted? && self.parameters == other.parameters
else
@parameters == other
end
end
# Returns a safe ActiveSupport::HashWithIndifferentAccess
# representation of this parameter with all unpermitted keys removed.
#
# params = ActionController::Parameters.new({
# name: 'Senjougahara Hitagi',
# oddity: 'Heavy stone crab'
# })
# params.to_h # => {}
#
# safe_params = params.permit(:name)
# safe_params.to_h # => {"name"=>"Senjougahara Hitagi"}
def to_h
if permitted?
convert_parameters_to_hashes(@parameters, :to_h)
else
slice(*self.class.always_permitted_parameters).permit!.to_h
end
end
# Returns an unsafe, unfiltered
# ActiveSupport::HashWithIndifferentAccess representation of this
# parameter.
#
# params = ActionController::Parameters.new({
# name: 'Senjougahara Hitagi',
# oddity: 'Heavy stone crab'
# })
# params.to_unsafe_h
# # => {"name"=>"Senjougahara Hitagi", "oddity" => "Heavy stone crab"}
def to_unsafe_h
convert_parameters_to_hashes(@parameters, :to_unsafe_h)
end
alias_method :to_unsafe_hash, :to_unsafe_h
# Convert all hashes in values into parameters, then yield each pair in
# the same way as Hash#each_pair
def each_pair(&block)
@parameters.each_pair do |key, value|
yield key, convert_hashes_to_parameters(key, value)
end
end
alias_method :each, :each_pair
# 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.
def converted_arrays
@converted_arrays ||= Set.new
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) # => #
def permit!
each_pair do |key, value|
Array.wrap(value).each do |v|
v.permit! if v.respond_to? :permit!
end
end
@permitted = true
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)
# # => "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.
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)
end
end
# Alias of #require.
alias :required :require
# 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: {})
#
# but 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 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)
# # => "555-1234"} permitted: true>} permitted: true>
#
# params.require(:person).permit(contact: [ :email, :phone ])
# # => "none@test.com", "phone"=>"555-1234"} permitted: true>} permitted: true>
def permit(*filters)
params = self.class.new
filters.flatten.each do |filter|
case filter
when Symbol, String
permitted_scalar_filter(params, filter)
when Hash then
hash_filter(params, filter)
end
end
unpermitted_parameters!(params) if self.class.action_on_unpermitted_parameters
params.permitted = true
params
end
# Returns a parameter for the given +key+. If not found,
# returns +nil+.
#
# params = ActionController::Parameters.new(person: { name: 'Francesco' })
# params[:person] # => "Francesco"} permitted: false>
# params[:none] # => nil
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.
def []=(key, value)
@parameters[key] = value
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 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) # => "Francesco"} permitted: false>
# params.fetch(:none) # => ActionController::ParameterMissing: param is missing or the value is empty: none
# params.fetch(:none, 'Francesco') # => "Francesco"
# params.fetch(:none) { 'Francesco' } # => "Francesco"
def fetch(key, *args)
convert_value_to_parameters(
@parameters.fetch(key) {
if block_given?
yield
else
args.fetch(0) { raise ActionController::ParameterMissing.new(key) }
end
}
)
end
if Hash.method_defined?(:dig)
# 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
def dig(*keys)
convert_value_to_parameters(@parameters.dig(*keys))
end
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) # => 1, "b"=>2} permitted: false>
# params.slice(:d) # =>
def slice(*keys)
new_instance_with_inherited_permitted_status(@parameters.slice(*keys))
end
# Returns current ActionController::Parameters instance which
# contains only the given +keys+.
def slice!(*keys)
@parameters.slice!(*keys)
self
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) # => 3} permitted: false>
# params.except(:d) # => 1, "b"=>2, "c"=>3} permitted: false>
def except(*keys)
new_instance_with_inherited_permitted_status(@parameters.except(*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) # => 1, "b"=>2} permitted: false>
# params # => 3} permitted: false>
def extract!(*keys)
new_instance_with_inherited_permitted_status(@parameters.extract!(*keys))
end
# Returns a new ActionController::Parameters 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 }
# # => 2, "b"=>4, "c"=>6} permitted: false>
def transform_values(&block)
if block
new_instance_with_inherited_permitted_status(
@parameters.transform_values(&block)
)
else
@parameters.transform_values
end
end
# Performs values transformation and returns the altered
# ActionController::Parameters instance.
def transform_values!(&block)
@parameters.transform_values!(&block)
self
end
# Returns a new ActionController::Parameters instance with the
# results of running +block+ once for every key. The values are unchanged.
def transform_keys(&block)
if block
new_instance_with_inherited_permitted_status(
@parameters.transform_keys(&block)
)
else
@parameters.transform_keys
end
end
# Performs keys transformation and returns the altered
# ActionController::Parameters instance.
def transform_keys!(&block)
@parameters.transform_keys!(&block)
self
end
# Deletes and returns a key-value pair from +Parameters+ whose key is equal
# to key. If the key is not found, returns the default value. If the
# optional code block is given and the key is not found, pass in the key
# and return the result of block.
def delete(key)
convert_value_to_parameters(@parameters.delete(key))
end
# Returns a new instance of ActionController::Parameters with only
# items that the block evaluates to true.
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.
def select!(&block)
@parameters.select!(&block)
self
end
alias_method :keep_if, :select!
# Returns a new instance of ActionController::Parameters with items
# that the block evaluates to true removed.
def reject(&block)
new_instance_with_inherited_permitted_status(@parameters.reject(&block))
end
# Removes items that the block evaluates to true and returns self.
def reject!(&block)
@parameters.reject!(&block)
self
end
alias_method :delete_if, :reject!
# Returns values that were assigned to the given +keys+. Note that all the
# +Hash+ objects will be converted to ActionController::Parameters.
def values_at(*keys)
convert_value_to_parameters(@parameters.values_at(*keys))
end
# Returns a new ActionController::Parameters with all keys from
# +other_hash+ merges into current hash.
def merge(other_hash)
new_instance_with_inherited_permitted_status(
@parameters.merge(other_hash.to_h)
)
end
# Returns current ActionController::Parameters instance which
# +other_hash+ merges into current hash.
def merge!(other_hash)
@parameters.merge!(other_hash.to_h)
self
end
# 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.
def stringify_keys # :nodoc:
dup
end
def inspect
"<#{self.class} #{@parameters} permitted: #{@permitted}>"
end
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
hook_into_yaml_loading
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
# backwardscompability above, otherwise equivalent to YAML's initialization.
@parameters, @permitted = coder.map["parameters"], coder.map["permitted"]
end
end
undef_method :to_param
# Returns duplicate of object including all parameters
def deep_dup
self.class.new(@parameters.deep_dup).tap do |duplicate|
duplicate.permitted = @permitted
end
end
protected
attr_reader :parameters
def permitted=(new_permitted)
@permitted = new_permitted
end
def fields_for_style?
@parameters.all? { |k, v| k =~ /\A-?\d+\z/ && (v.is_a?(Hash) || v.is_a?(Parameters)) }
end
private
def new_instance_with_inherited_permitted_status(hash)
self.class.new(hash).tap do |new_instance|
new_instance.permitted = @permitted
end
end
def convert_parameters_to_hashes(value, using)
case value
when Array
value.map { |v| convert_parameters_to_hashes(v, using) }
when Hash
value.transform_values do |v|
convert_parameters_to_hashes(v, using)
end.with_indifferent_access
when Parameters
value.send(using)
else
value
end
end
def convert_hashes_to_parameters(key, value)
converted = convert_value_to_parameters(value)
@parameters[key] = converted unless converted.equal?(value)
converted
end
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
converted
when Hash
self.class.new(value)
else
value
end
end
def each_element(object)
case object
when Array
object.grep(Parameters).map { |el| yield el }.compact
when Parameters
if object.fields_for_style?
hash = object.class.new
object.each { |k, v| hash[k] = yield v }
hash
else
yield object
end
end
end
def unpermitted_parameters!(params)
unpermitted_keys = unpermitted_keys(params)
if unpermitted_keys.any?
case self.class.action_on_unpermitted_parameters
when :log
name = "unpermitted_parameters.action_controller"
ActiveSupport::Notifications.instrument(name, keys: unpermitted_keys)
when :raise
raise ActionController::UnpermittedParameters.new(unpermitted_keys)
end
end
end
def unpermitted_keys(params)
keys - params.keys - always_permitted_parameters
end
#
# --- Filtering ----------------------------------------------------------
#
# This is a white 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 API of +permit+ above.
PERMITTED_SCALAR_TYPES = [
String,
Symbol,
NilClass,
Numeric,
TrueClass,
FalseClass,
Date,
Time,
# DateTimes are Dates, we document the type but avoid the redundant check.
StringIO,
IO,
ActionDispatch::Http::UploadedFile,
Rack::Test::UploadedFile,
]
def permitted_scalar?(value)
PERMITTED_SCALAR_TYPES.any? { |type| value.is_a?(type) }
end
def permitted_scalar_filter(params, key)
if has_key?(key) && permitted_scalar?(self[key])
params[key] = self[key]
end
keys.grep(/\A#{Regexp.escape(key)}\(\d+[if]?\)\z/) do |k|
if permitted_scalar?(self[k])
params[k] = self[k]
end
end
end
def array_of_permitted_scalars?(value)
if value.is_a?(Array) && value.all? { |element| permitted_scalar?(element) }
yield value
end
end
def non_scalar?(value)
value.is_a?(Array) || value.is_a?(Parameters)
end
EMPTY_ARRAY = []
EMPTY_HASH = {}
def hash_filter(params, filter)
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
if filter[key] == EMPTY_ARRAY
# Declaration { comment_ids: [] }.
array_of_permitted_scalars?(self[key]) do |val|
params[key] = val
end
elsif filter[key] == EMPTY_HASH
# Declaration { preferences: {} }.
if value.is_a?(Parameters)
params[key] = permit_any_in_parameters(value)
end
elsif non_scalar?(value)
# Declaration { user: :name } or { user: [:name, :age, { address: ... }] }.
params[key] = each_element(value) do |element|
element.permit(*Array.wrap(filter[key]))
end
end
end
end
def permit_any_in_parameters(params)
self.class.new.tap do |sanitized|
params.each do |key, value|
if permitted_scalar?(value)
sanitized[key] = value
elsif value.is_a?(Array)
sanitized[key] = permit_any_in_array(value)
elsif value.is_a?(Parameters)
sanitized[key] = permit_any_in_parameters(value)
else
# Filter this one out.
end
end
sanitized.permitted = true
end
end
def permit_any_in_array(array)
[].tap do |sanitized|
array.each do |element|
if permitted_scalar?(element)
sanitized << element
elsif element.is_a?(Parameters)
sanitized << permit_any_in_parameters(element)
else
# Filter this one out.
end
end
end
end
def initialize_copy(source)
super
@parameters = @parameters.dup
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::ForbiddenAttributesError 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!(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 accepts_nested_attributes_for with Strong \Parameters, you
# will need to specify which nested attributes should be whitelisted. You might want
# to allow +:id+ and +:_destroy+, see ActiveRecord::NestedAttributes for more information.
#
# 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: [ :id, :name, :category ])
# end
# end
#
# See ActionController::Parameters.require and ActionController::Parameters.permit
# for more information.
module StrongParameters
extend ActiveSupport::Concern
include ActiveSupport::Rescuable
# Returns a new ActionController::Parameters object that
# has been instantiated with the request.parameters.
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