Simple Captcha

Version: edge Author: Sur [http://expressica.com] Plugin Homepage: http://expressica.com/simple_captcha Contributors: http://vinsol.com/team, Kei Kusakari [http://d.hatena.ne.jp/kusakari/about] License: MIT

Introduction:

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 Rails2.0 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.

Pre-Requisite

RMagick should be installed on your machine to use this plugin. visit http://rmagick.rubyforge.org for more details.

Installation

SimpleCaptcha plugin can be installed by running this command from the application root

ruby script/plugin install svn://rubyforge.org/var/svn/expressica/plugins/simple_captcha

OR

SVN checkout the plugin as
svn co svn://rubyforge.org/var/svn/expressica/plugins/simple_captcha simple_captcha
Now put the directory simple_captcha in your application as /vendor/plugins/simple_captcha

Setup

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

STEP 1

for rails >= 2.0 —-—-—- >> rake simple_captcha:setup

for rails < 2.0

rake simple_captcha:setup_old

STEP 2

rake db:migrate

STEP 3

add the following code in the file config/routes.rb

ActionController::Routing::Routes.draw do |map|
    map.simple_captcha '/simple_captcha/:action', :controller => 'simple_captcha'
  end

This is a mandatory route used for rendering the simple_captcha image on the fly without 
storing on the filesyste.

STEP 4

add the following line in the file app/controllers/application.rb

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

Usage

Controller Based

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

class User < ActiveRecord::Basse
  apply_simple_captcha
end

Validating with captcha

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

Saving with captcha

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

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”

: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’.

:object

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

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. For Rails >= 2.0 the file wiil reside as… ”/app/views/simple_captcha/_simple_captcha.erb” For Rails < 2.0 the file will reside as… ”/app/views/simple_captcha/_simple_captcha.rhtml”

View’s Examples

Controller Based Example

example ——- <%= show_simple_captcha(:label => “human authentication”) %>

example

<%= show_simple_captcha(:label => “human authentication”, :image_style => ‘embosed_silver’) %>

example

<%= show_simple_captcha(:label => “human authentication”, :image_style => ‘simply_red’, :distortion => ‘medium’) %>

Model Based Example

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

example

class User < ActiveRecord::Base apply_simple_captcha end

example

class User < ActiveRecord::Base apply_simple_captcha :message => “The secret Image and code were different”, :add_to_base => true end

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Enjoy the simplest captcha implementation.
Author: Sur
Blog: http://expressica.com
Contact: sur.max@gmail.com
Plugin Homepage: http://expressica.com/simple_captcha

Any feedback/comment/issue/donation is welcome!

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NOTE: This description has been extracted from the Plugin README and so the formatting may need updating to make browser friendly