SimpleCaptcha

SimpleCaptcha is the simplest and a robust captcha plugin. Its implementation requires adding up a single line in views and in controllers/models. SimpleCaptcha is available to be used with Rails 3 or above and also it provides the backward compatibility with previous versions of Rails.

Features

• Zero FileSystem usage(secret code moved to db-store and image storage removed).

• Provides various image styles.

• Provides three level of complexity of images.

• Works absolutely fine in distributed environment(session and db based implementation works fine in distributed environment).

• Implementation is as easy as just writing a single line in your view. “<%= show_simple_captcha %>” within the ‘form’ tags.

• Flexible DOM and CSS handling(There is a separate view partial for rednering SimpleCaptcha DOM elements).

• Automated removal of 1 hour old unmatched simple_captcha data.

Requirements

• Ruby >= 1.8.7

• Rails >= 3

• ImageMagick should be installed on your machine to use this plugin. visit www.imagemagick.org/script/index.php for more details.

Installation

gem"galetahub-simple_captcha", :require=>"simple_captcha"

or

gem'galetahub-simple_captcha', :require=>'simple_captcha', :git=>'git://github.com/galetahub/simple-captcha.git'

Setup

After installation, follow these simple steps to setup the plugin. The setup will depend on the version of rails your application is using.

railsgeneratesimple_captcharakedb:migrate

Usage

Controller Based

Add the following line in the file “app/controllers/application.rb”

ApplicationController < ActionController::Base
include SimpleCaptcha::ControllerHelpers
end

In the view file within the form tags add this code

<%= show_simple_captcha %>

and in the controller’s action authenticate it as

if simple_captcha_valid?
do this
else
do that
end

Model Based

In the view file within the form tags write this code

<%= show_simple_captcha(:object=>"user") %>

and in the model class add this code

classUser<ActiveRecord::Baseapply_simple_captchaend

FormBuilder helper

<%= form_for @user do |form| -%>
...
<%= form.simple_captcha :label => "Enter numbers.." %>
...
<% end -%>

Validating with captcha

NOTE: @user.valid? will still work as it should, it will not validate the captcha code.

@user.valid_with_captcha?

Saving with captcha

NOTE: @user.save will still work as it should, it will not validate the captcha code.

@user.save_with_captcha

Formtastic integration

SimpleCaptcha detects if your use Formtastic and appends “SimpleCaptcha::CustomFormBuilder”.

<%= form.input :captcha, :as => :simple_captcha %>

Options & Examples

View Options

• label - provides the custom text b/w the image and the text field, the default is “type the code from the image”

• object - the name of the object of the model class, to implement the model based captcha.

• code_type - return numeric only if set to ‘numeric’

Global options

• image_style - provides the specific image style for the captcha image.

There are eight different styles available with the plugin as…

1) simply_blue
2) simply_red
3) simply_green
4) charcoal_grey
5) embosed_silver
6) all_black
7) distorted_black
8) almost_invisible

Default style is ‘simply_blue’. You can also specify ‘random’ to select the random image style.

• distortion - handles the complexity of the image. The :distortion can be set to ‘low’, ‘medium’ or ‘high’. Default is ‘low’.

Create “rails_root/config/initializers/simple_captcha.rb”

SimpleCaptcha.setupdo|sc|# default: 100x28sc.image_size = '120x40'# default: 5sc.length = 6# default: simply_blue# possible values:# 'embosed_silver',# 'simply_red',# 'simply_green',# 'simply_blue',# 'distorted_black',# 'all_black',# 'charcoal_grey',# 'almost_invisible'# 'random'sc.image_style = 'simply_green'# default: low# possible values: 'low', 'medium', 'high', 'random'sc.distortion = 'medium'end

You can add your own style:

SimpleCaptcha.setupdo|sc|sc.image_style = 'mycaptha'sc.add_image_style('mycaptha', [
"-background '#F4F7F8'",
"-fill '#86818B'",
"-border 1",
"-bordercolor '#E0E2E3'"])
end

You can provide the path where image_magick is installed as well:

SimpleCaptcha.setupdo|sc|sc.image_magick_path = '/usr/bin'# you can check this from console by running: which convertend

You can provide the path where should be stored tmp files. It’s usefull when you dont have acces to /tmp (default directory)

SimpleCaptcha.setupdo|sc|sc.tmp_path = '/tmp'# or somewhere in project eg. Rails.root.join('tmp/simple_captcha').to_s, make shure directory existsend

How to change the CSS for SimpleCaptcha DOM elements?

You can change the CSS of the SimpleCaptcha DOM elements as per your need in this file.

/app/views/simple_captcha/_simple_captcha.erb

View’s Examples

Controller Based Example

<%= show_simple_captcha %>
<%= show_simple_captcha(:label => "human authentication") %>

Model Based Example

<%= show_simple_captcha(:object => 'user', :label => "human authentication") %>

Model Options

• message - provides the custom message on failure of captcha authentication the default is “Secret Code did not match with the Image”

• add_to_base - if set to true, appends the error message to the base.

Model’s Example

classUser<ActiveRecord::Baseapply_simple_captchaendclassUser<ActiveRecord::Baseapply_simple_captcha:message=>"The secret Image and code were different", :add_to_base=>trueend

I18n

simple_captcha:
message:
default: "Secret Code did not match with the Image"
user: "The secret Image and code were different"

Who’s who?

Enjoy the simplest captcha implementation.

Author: Sur

Blog: expressica.com

Contact: sur.max@gmail.com

Plugin Homepage: expressica.com/simple_captcha

Plugin update for rails 3: github.com/galetahub

Any feedback/comment/issue/donation is welcome!