require 'active_support/core_ext/hash/slice'
require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/module/anonymous'
require 'action_dispatch/http/mime_type'
module ActionController
# 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
# <tt>attribute_names</tt>.
#
# If you're going to pass the parameters to an +ActiveModel+ object (such as
# <tt>User.new(params[:user])</tt>), 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 <tt>Admin::User</tt> 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.
module ParamsWrapper
extend ActiveSupport::Concern
EXCLUDE_PARAMETERS = %w(authenticity_token _method utf8)
require 'mutex_m'
class Options < Struct.new(:name, :format, :include, :exclude, :klass, :model) # :nodoc:
include Mutex_m
def self.from_hash(hash)
name = hash[:name]
format = Array(hash[:format])
include = hash[:include] && Array(hash[:include]).collect(&:to_s)
exclude = hash[:exclude] && Array(hash[:exclude]).collect(&:to_s)
new name, format, include, exclude, nil, nil
end
def initialize(name, format, include, exclude, klass, model) # :nodoc:
super
@include_set = include
@name_set = name
end
def model
super || synchronize { super || self.model = _default_wrap_model }
end
def include
return super if @include_set
m = model
synchronize do
return super if @include_set
@include_set = true
unless super || exclude
if m.respond_to?(:attribute_names) && m.attribute_names.any?
self.include = m.attribute_names
end
end
end
end
def name
return super if @name_set
m = model
synchronize do
return super if @name_set
@name_set = true
unless super || klass.anonymous?
self.name = m ? m.to_s.demodulize.underscore :
klass.controller_name.singularize
end
end
end
private
# Determine the wrapper model from the controller's name. By convention,
# this could be done by trying to find the defined model that has the
# same singular name as the controller. For example, +UsersController+
# will try to find if the +User+ model exists.
#
# This method also does namespace lookup. Foo::Bar::UsersController will
# try to find Foo::Bar::User, Foo::User and finally User.
def _default_wrap_model #:nodoc:
return nil if klass.anonymous?
model_name = klass.name.sub(/Controller$/, '').classify
begin
if model_klass = model_name.safe_constantize
model_klass
else
namespaces = model_name.split("::")
namespaces.delete_at(-2)
break if namespaces.last == model_name
model_name = namespaces.join("::")
end
end until model_klass
model_klass
end
end
included do
class_attribute :_wrapper_options
self._wrapper_options = Options.from_hash(format: [])
end
module ClassMethods
def _set_wrapper_options(options)
self._wrapper_options = Options.from_hash(options)
end
# Sets the name of the wrapper key, or the model which +ParamsWrapper+
# would use to determine the attribute names from.
#
# ==== Examples
# wrap_parameters format: :xml
# # enables the parameter wrapper for XML format
#
# wrap_parameters :person
# # wraps parameters into +params[:person]+ hash
#
# wrap_parameters Person
# # wraps parameters by determining the wrapper key from Person class
# (+person+, in this case) and the list of attribute names
#
# wrap_parameters include: [:username, :title]
# # wraps only +:username+ and +:title+ attributes from parameters.
#
# wrap_parameters false
# # disables parameters wrapping for this controller altogether.
#
# ==== Options
# * <tt>:format</tt> - The list of formats in which the parameters wrapper
# will be enabled.
# * <tt>:include</tt> - The list of attribute names which parameters wrapper
# will wrap into a nested hash.
# * <tt>:exclude</tt> - The list of attribute names which parameters wrapper
# will exclude from a nested hash.
def wrap_parameters(name_or_model_or_options, options = {})
model = nil
case name_or_model_or_options
when Hash
options = name_or_model_or_options
when false
options = options.merge(:format => [])
when Symbol, String
options = options.merge(:name => name_or_model_or_options)
else
model = name_or_model_or_options
end
opts = Options.from_hash _wrapper_options.to_h.slice(:format).merge(options)
opts.model = model
opts.klass = self
self._wrapper_options = opts
end
# Sets the default wrapper key or model which will be used to determine
# wrapper key and attribute names. Will be called automatically when the
# module is inherited.
def inherited(klass)
if klass._wrapper_options.format.any?
params = klass._wrapper_options.dup
params.klass = klass
klass._wrapper_options = params
end
super
end
end
# Performs parameters wrapping upon the request. Will be called automatically
# by the metal call stack.
def process_action(*args)
if _wrapper_enabled?
if request.parameters[_wrapper_key].present?
wrapped_hash = _extract_parameters(request.parameters)
else
wrapped_hash = _wrap_parameters request.request_parameters
end
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
private
# Returns the wrapper key which will be used to store wrapped parameters.
def _wrapper_key
_wrapper_options.name
end
# Returns the list of enabled formats.
def _wrapper_formats
_wrapper_options.format
end
# Returns the list of parameters which will be selected for wrapped.
def _wrap_parameters(parameters)
{ _wrapper_key => _extract_parameters(parameters) }
end
def _extract_parameters(parameters)
if include_only = _wrapper_options.include
parameters.slice(*include_only)
else
exclude = _wrapper_options.exclude || []
parameters.except(*(exclude + EXCLUDE_PARAMETERS))
end
end
# Checks if we should perform parameters wrapping.
def _wrapper_enabled?
ref = request.content_mime_type.try(:ref)
_wrapper_formats.include?(ref) && _wrapper_key && !request.request_parameters[_wrapper_key]
end
end
end
