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 © 2010 Jakub Kuźma. See LICENSE for details.