new(パラメータ={}, ロギングコンテクスト={})

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">

slice(キー..)

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>

except(キー..)

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>

permit(フィルター..)

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

permit!()

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">

dig(キー..)

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

fetch(キー, パラメータ..)

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"

extract!(キー..)

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>

to_h()

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"}

to_hash()

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"}

to_query(引数..)

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"

to_unsafe_h()

params = ActionController::Parameters.new({
name: "Senjougahara Hitagi",
oddity: "Heavy stone crab"
})
params.to_unsafe_h
#=> {"name"=>"Senjougahara Hitagi", "oddity" => "Heavy stone crab"}

require(キー))

ActionController::Parameters.new(person: { name: "Francesco" }).require(:person)
#=> <ActionController::Parameters {"name"=>"Francesco"} permitted: false>

permitted?()

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

transform_values()

# 失敗したら例外発生
transform_values!()

params = ActionController::Parameters.new({
name: "Senjougahara Hitagi",
oddity: "Heavy stone crab"
})
params.to_unsafe_h
#=> {"name"=>"Senjougahara Hitagi", "oddity" => "Heavy stone crab"}