Resources
It's a gem that help's you to create CRUD controllers for your models in a very fast and flexible way.
Note: Version 1.0.0+ introduces some breaking changes, to see the list of this change please check CHANGE_LOG.md
Installation
Add this line to your application's Gemfile:
gem 'resources'
And then execute:
bundle install
Or install it yourself as:
$ gem install resources
Rub the configuration generator, this will create the resources initializer
rails g resources:install
USAGE
Just add resource_for to your controller and give the model's name
class Admin::CountriesController < ApplicationController
  resource_for "Country"
end
or use the controller generator
rails g resource_controller admin/country
And that's it, you have to do anything else on the controller to create a CRUD maintenance for the country model.
resource_for will handle all the restful actions for you and it will give you the next's helper_methods for your convenience:
resources: this will have a collection of Country, objects so you can use on the index actions or any other collection route actions of your controller
resource: this will have a  Country, object so you can use on the member route actions like  new, create, edit, update, show, destroy
resources_search:  this is a ransack object to you in the search_form_for helper
resource_saved?: this is a helper to user after create or update a record to know if it was saved.
OPTIONS AND FLEXIBILITY
resource_for by default expects the params key for update or create the object to be resource if you use form_for or simple_form you need to add the as: :resource option
= simple_form_for [:admin, resource], as: :resource do |f|
  = f.input :code
  = f.input :name
  = f.input :active
  = f.submit "SAVE"
RESOURCE PARAMS -  params_resource
This options allows you to change the default params key used for create or update the record. So you don't have to add the as: :resource to the simple_form_for.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    params_resource: :country
end
Note: For Rails 4 you may encounter with this error (ActiveModel::ForbiddenAttributesError)  when you try to update a record  due to strong_parameters protection. To avoid this just add to your model a method named permited_attributes that return an array of allowed attributes. Example
class Country < ActiveRecord::Base
  def permited_attributes
    [:name, :code, :active]
  end
end
Or you can use the  lambda syntax.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    params_resource: lambda{ |params|   params[:country] }
end
# For rails 4
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    params_resource: lambda{ |params|
      params.require(:country).permit(:name)
    }
end
RESOURCE ALIAS - resource_method_name - resources_method_name
This options allows you to alias the resource method in case you don't like the name.  if you don't specify a resources_method_name it will name the alias to resource_method_name pluralized.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    params_resource: :country,
    resource_method_name: :country
end
NOTE: making a change in resource_method_name and resources_method_name options requires a server restart.
Now in your view you can use country instead of resource
= simple_form_for [:admin, country] do |f|
  = f.input :code
  = f.input :name
  = f.input :active
  = f.submit "SAVE"
PAGINATION - pagination
This option enable pagination in case that you use any of the most popular pagination gems (kaminari or will_paginate).
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    pagination: true,
    params_resource: :country,
    resource_method_name: :country
end
Or you can use the  lambda syntax.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    pagination: lambda{ |params, controller| params[:disable_pagination].blank? },
    params_resource: :country,
    resource_method_name: :country
end
DEFAULT SCOPES - resource_scope- resources_scope
This options are to set a default scope for the resources, and resource objects.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    resources_scope: :active,
    pagination: true,
    params_resource: :country,
    resource_method_name: :country
end
Note: this will execute the scope active and get you only the countries that are currently actives.
You can use the  lambda syntax for a more complex scope.
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    resources_scope: lambda{ |scope, params, controller|
      scope.by_active_state(params[:active_state]).includes(:cities)
    },
    pagination: true,
    params_resource: :country,
    resource_method_name: :country
end
SEARCH - search- search_options
The search option enable ransack in case that you have installed it. And the search_options allows you to pass a hash of parameters to the result method of ransack like distinct: true
class Admin::CountriesController < ApplicationController
  resource_for :"Country",
    search: true,
    search_options: {distinct: true},
    resources_scope: :active,
    pagination: true,
    params_resource: :country,
    resource_method_name: :country
end
NOTE: For the use of the** search_form_for** you have the resources_search helper that is a racksack object or in this case countries_search because we used the resource alias resource_method_name
= search_form_for [:admin, countries_search] do |f|
  = f.label :name_cont
  = f.search_field :name_cont
  = f.submit
*Overriding methods *
*Redirects *
By default, after any of the REST actions that modify the record  (create, update, destroy) it redirects to the index action of that controller, but if you define method  after_#{action_name}_path_for  that returns  a path it will execute this method and redirect to that particular path.
Example
  def after_create_path_for
    root_url
  end
NOTE: After creating the record it will redirect to the root_url
default REST actions
If you want to override any of the REST actions, to add any extra logic that you may need, you can just pass a block to the save_resource or destroy_resource inside the actions and add your custom logic there.
Example
  def create
    save_resource do
      # Add you complex logic here
      if resource_saved?
        flash[:notice] = I18n.t("app.record_successfully_created")
        redirect_to root_url and return
      else
        render action: :new
      end
    end
  end
NOTE: Remember that you can make use of the  resource_saved? method to know if the record has been saved
*Using it with Grape *
If you are using resources with the Grape gem fallow the next steps:
In your Gemfile add the resources after grape
gem "grape"
gem 'grape-raketasks'
gem "hashie-forbidden_attributes"
gem "resources"
Now in your api class add the helpers ::Resources::GrapeHelpers and in the execute the  resource_for inside a before block.
require "resources"
require "resources/grape_helpers" # only need to add this line if you didnt do the previous step
module Twitter
  class API < Grape::API
    version 'v1', using: :header, vendor: 'twitter'
    format :json
    prefix :api
    helpers ::Resources::GrapeHelpers
    before do
      resource_for :"Country"
    end
    resource :countries do
      desc "Return a list of countries."
      get do
        resources
      end
      desc "Return a country."
      get ':id' do
        resource
      end
      desc "Update a country."
      put ':id' do
        save_resource
      end
    end
  end
end
NOTE: Currently there is a limitation, the option resource_method_name doesn't work inside grape
*GLOBAL CONFIGURATION *
You can change the default parameters of any configuration by change the options in the config/initializers/resources.rb that was generated by running rails g resources:install
Resources.config do |config|
  config.params_search = :q # ransack search parameter. Default params[:q]
  config.params_resource = :resource # resource parameter to be saved.  
end
Copyright
Copyright (c) 2015 Emilio Forrer. See LICENSE.txt for further details.