Module | ActionController::ParamsWrapper |
In: |
lib/action_controller/metal/params_wrapper.rb
|
Wraps the parameters hash into a nested hash. This will allow clients to submit POST requests without having to specify any root elements.
This functionality is enabled in +config/initializers/wrap_parameters.rb+ and can be customized. If you are upgrading to \Rails 3.1, this file will need to be created for the functionality to be enabled.
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] 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
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.