Simple Captcha in rails 3

Here I will show you how to add captcha in rails 3 application:

Download Simple captcha plugin from the git : click here

1	rails plugin install https://github.com/galetahub/simple-captcha.git

Generate Simple Captcha

1 2	rails generate simple_captcha rake db:migrate

Generate scaffold of MODEL

1	rails g scaffold Model

Captcha code can be added two way . 1. Controller based 2. Model based

Controller Based

Include simple captcha in app/controllers/application.rb

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

Add captcha code in form page

1	<%=show_simple_captcha%>

Check captcha authentication in controller

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def create   if simple_captcha_valid?     do something....   else     do something....   end end

Model Based
Add captcha in model

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class Model < ActiveRecord::Base    apply_simple_captcha end

In Form page

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

In controller

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@object.valid_with_captcha? or @object.save_with_captcha

ADD I18n

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

If application is in ruby 1.9.* then you need to require some changes in plugins otherwise you will not able to see captcha image and get following error

1	"TypeError (can't convert nil into Integer):"

Changes in /simple-captcha/lib/simple_captcha/image.rb 
At line number 47: Comment class Tempfile

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#class Tempfile < ::Tempfile   # Replaces Tempfile's +make_tmpname+ with one that honors file extensions.   # def make_tmpname(basename, n = 0)   # puts "**********************Base name: #{basename}"   # extension = File.extname(basename)   # puts "**********************Extension: #{extension}"   # puts "********************** SPRINFG #{File.basename(basename, extension)},#{$$},#{n.to_i}#{extension}"   #   # # sprintf("%s,%d,%d%s", File.basename(basename, extension), $$, n, extension)   # sprintf("%s%d-%d%s", File.basename(basename, extension), $$, n, extension)   # #"%s,%d,%d%s", File.basename(basename, extension), $$, n, extension   # puts "**********************Base name: #{basename}"   # end   # end

At line number 68: replace with below code

1	dst = Tempfile.new(['simple_captcha','.jpg'])