= Double Trouble

Adds nonces to your Rails' forms, avoiding duplicates by sending the
same form again (when the user has ADHD, as well in the other
situations).

== Installation

  gem install double_trouble

== Usage

  class CommentsController < ApplicationController
    protect_from_double_trouble :comment, :only => :create

    def create
      @comment = Comment.new(params[:comment])
      if @comment.save
        # ordinary stuff
      end
    end
  end

Double trouble works quite similar to CSRF protection
(authenticity_token) - it adds form_nonce parameter to your
forms. After the protected model is successfully saved (when
new_record? returns false), it stores received form_nonce in the
Rails.cache by default (you can easily replace the default store by DB
backend for instance).

== Configuration

You can globally turn the protection off (test environment?):

  ActionController::Base.allow_double_trouble_protection = false

Default nonce store can be changed:

  ActionController::Base.double_trouble_nonce_store = FormNonce

FormNonce class must implement two class methods:

  def self.valid?(nonce)
    # checks if the nonce has not been used before
  end

  def self.store!(nonce)
    # stores the given nonce somewhere
  end

The name of the form nonce param can be changed as well:

  ActionController::Base.double_trouble_nonce_param = :double_trouble_nonce

== Copyright

Copyright (c) 2010 Jakub Kuźma. See LICENSE[http://github.com/qoobaa/form_nonce/raw/master/LICENSE] for details.