Simple Captcha Reloaded

This is a rewrite of the popular Simple-Captcha Gem. Similarily to Simple-Captcha, it provides an easy way to integrate a Captcha into a Rails appliaction. In comparison to the older Gem(s), I decided to drop support for ancient versions of Rails + Formtastic + Mongoid, but also add specs and support for SimpleForm.

Features

• Works with Rails 4.1+, Ruby 2.0+ (keyword arguments)
• Integrated into Model validation flow
• Optional controller integration for custom flow
• Uses a database table to track random captchas
• Uses imagemagick to generate the captcha and stream it to the client, without file access

Prerequisites

This needs Rails (4.1+), ActiveRecord with a database (all should be fine) and imagemagick.

Mac:

brew install imagemagick ghostscript

Linux:

apt-get install imagemagick ghostscript

Usage

Put it into your Gemfile:

gem 'simple_captcha_reloaded'

and run bundle install.

Install the migration to create the captcha data table:

rake simple_captcha_reloaded:install:migrations
rake db:migrate

Integration 1: Model based

Just integrate the module into on of your ActiveModel::Model compliant Models:

class Message < ActiveRecord::Base
  include SimpleCaptchaReloaded::Model
end

this adds 2 new methods: valid_with_captcha? and save_with_captcha to the model. Use it like this in controller:

class MessagesController < ApplicationController
  def submit
    @message = Message.new(message_params)
    if @message.save_with_captcha
      ...
    else
      render :new
    end
  end

  def message_params
    params.require(:message).permit(..., :captcha, :captcha_key)
  end
end

Make sure to whiteliste the attributes captcha and captcha_key with Strong Parameters.

To show the captcha, you can use the SimpleForm helper:

Simple Form

The Gem provides a custom input for SimpleForm:

= simple_form_for @model do |f|
  = f.input :captcha, as: :simple_captcha
  = f.submit

Formtastic

PLANNED

Manual by using default Rails view helper

Similar to "Displaying Captcha" below, just change the key and value calls of the simple_captcha helper method to match your model:

= simple_captcha(key: 'user[captcha_key]', value: 'user[captcha]', refresh_button: true)

Integration II - Controller

If you need to use the captcha without a model, you can do the show and validation by hand

Displaying Captcha

Within your form, call the function:

= form_tag '' do |f|
  = simple_captcha(key: :captcha_key, value: :captcha, refresh_button: true)
  = submit_tag 'send'

This method is a thin wrapper which will render the view simple_captcha_reloaded/simple_captcha_reloaded.html in the end. As this is a Rails engine, you can overwrite the view by creating a app/views/simple_captcha_reloaded/_simple_captcha_reloaded.html.erb in your project tree.

Adjust it to your needs:

<div class='simple-captcha-wrapper' id='<%=id %>'>
  <%= hidden_field_tag key, captcha[:captcha_id] %>
  <%= image_tag captcha[:captcha_url], class: 'simple-captcha-image' %>
  <%= text_field_tag value, '', class: 'simple-captcha-input' %>
  <%- if refresh_button %>
    <%=link_to t('simple_captcha_reloaded.refresh_button_html'), captcha[:refresh_url], data: { remote: true} %>
  <% end %>
</div>

Manual Validation

Now you can call a method in your controller to check if the captcha is valid:

def submit
  if captcha_valid?(params[:captcha_key], params[:captcha])
    ..
  else
    ... error
  end
end

Customizing

Captcha Options

# Default Options
SimpleCaptchaReloaded::Config.tap do |config|
  config.captcha_path = '/simple_captcha'
  config.image = SimpleCaptchaReloaded::Image.new
  config.characters = %w[a b c d e f g h j k m n p q r s t u v w x y z 0 2 3 4 5 6 8 9]
  config.length = 6
end

To change the appearance of the Captcha, initialize a SimpleCaptchaReloaded::Image.new with different parameters (default parameters shown):

  config.image = SimpleCaptchaReloaded::Image.new(implode: :medium,
    distortion: :random,
    image_styles: IMAGE_STYLES.slice('simply_red', 'simply_green', 'simply_blue'),
    noise: 0,
    size: '100x28',
    image_magick_path: '',
    tmp_path: nil
  )

# whereas IMAGE_STYLES are:
IMAGE_STYLES = {
  'embosed_silver'  => ['-fill darkblue', '-shade 20x60', '-background white'],
  'simply_red'      => ['-fill darkred', '-background white'],
  'simply_green'    => ['-fill darkgreen', '-background white'],
  'simply_blue'     => ['-fill darkblue', '-background white'],
  'distorted_black' => ['-fill darkblue', '-edge 10', '-background white'],
  'all_black'       => ['-fill darkblue', '-edge 2', '-background white'],
  'charcoal_grey'   => ['-fill darkblue', '-charcoal 5', '-background white'],
  'almost_invisible' => ['-fill red', '-solarize 50', '-background white']
}

Contributing

Report bugs/feature requests to the Github issues. If you'd like to contribute, here a little setup guide. The Gem uses Appraisal, to create various configuration Gem sets. For each Gem set, a new dummy app will be automatically created.

1. Fork, and clone
2. bundle
3. appraisal install
4. appraisal rails-stable make regenerate To build the dummy app with the Rails-Stable configuration
5. appraisal rails-stable rspec To run tests

If you need to add new controller methods to the dummy app, have a look at spec/template.rb