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
On ActiveRecord 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.