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Module: ActionController::ParamsWrapper

Relationships & Source Files
Namespace Children
Modules:
ClassMethods
Extension / Inclusion / Inheritance Descendants
Included In:
API, Base, ::ActionView::TestCase::TestController, Rails::ApplicationController, Rails::InfoController, Rails::MailersController, Rails::WelcomeController
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::ActiveSupport::Concern
Defined in: actionpack/lib/action_controller/metal/params_wrapper.rb

Overview

Wraps the parameters hash into a nested hash. This will allow clients to submit requests without having to specify any root elements.

This functionality is enabled in config/initializers/wrap_parameters.rb and can be customized.

You could also turn it on per controller by setting the format array to a non-empty array:

class UsersController < ApplicationController
  wrap_parameters format: [:json, :xml, :url_encoded_form, :multipart_form]
end

If you enable ParamsWrapper for :json format, instead of having to send JSON parameters like this:

{"user": {"name": "Konata"}}

You can send parameters like this:

{"name": "Konata"}

And it will be wrapped into a nested hash with the key name matching the controller’s name. For example, if you’re posting to UsersController, your new params hash will look like this:

{"name" => "Konata", "user" => {"name" => "Konata"}}

You can also specify the key in which the parameters should be wrapped to, and also the list of attributes it should wrap by using either :include or :exclude options like this:

class UsersController < ApplicationController
  wrap_parameters :person, include: [:username, :password]
end

On Active Record models with no :include or :exclude option set, it will only wrap the parameters returned by the class method attribute_names.

If you’re going to pass the parameters to an ::ActiveModel object (such as User.new(params[:user])), you might consider passing the model class to the method instead. The ParamsWrapper will actually try to determine the list of attribute names from the model and only wrap those attributes:

class UsersController < ApplicationController
  wrap_parameters Person
end

You still could pass :include and :exclude to set the list of attributes you want to wrap.

By default, if you don’t specify the key in which the parameters would be wrapped to, ParamsWrapper will actually try to determine if there’s a model related to it or not. This controller, for example:

class Admin::UsersController < ApplicationController
end

will try to check if Admin::User or User model exists, and use it to determine the wrapper key respectively. If both models don’t exist, it will then fallback to use user as the key.

Constant Summary

Class Method Summary

::ActiveSupport::Concern - Extended

append_features, class_methods, included

Instance Method Summary

DSL Calls

included

[ GitHub ] 


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# File 'actionpack/lib/action_controller/metal/params_wrapper.rb', line 171

included do
  class_attribute :_wrapper_options, default: Options.from_hash(format: [])
end

Instance Method Details

#process_action(*args)

Performs parameters wrapping upon the request. Called automatically by the metal call stack.

[ GitHub ] 

  


# File 'actionpack/lib/action_controller/metal/params_wrapper.rb', line 243



def process_action(*args)
  if _wrapper_enabled?
    wrapped_hash = _wrap_parameters request.request_parameters
    wrapped_keys = request.request_parameters.keys
    wrapped_filtered_hash = _wrap_parameters request.filtered_parameters.slice(*wrapped_keys)

    # This will make the wrapped hash accessible from controller and view.
    request.parameters.merge! wrapped_hash
    request.request_parameters.merge! wrapped_hash

    # This will display the wrapped hash in the log file.
    request.filtered_parameters.merge! wrapped_filtered_hash
  end
  super
end