Update: SimpleCaptcha 1.2.2 is up!!

Major Changes…

FileSystem Usage Removed

Works Perfectly with Multiple Clustered Servers

Read Here for more details on implementation, usage and examples.

sur captcha, plugin, rails, ruby, rubyonrails, validations

Simple Captcha 1.0 released

If you are using an older revision of SimpleCaptcha then it is strongly recommended that update it to the Simple Captcha version 1.0, coz there were certain bugs in the previous release viz. update_attribute, which has been fixed in this release.

Bugs Fixed and Features

• update_attribute and update_attributes are now working
• Automated removal of old simple captcha images
• can be implemented as controller or model based captcha
• implementation requires a single line of code in view and a single line of code in controller/model
• customized CSS can be implemented
• Distortion of images can be selected from three different levels as low, medium or high…
  so that now we can handle the complexities of images
• Eight different styles of images are available to be selected as your captcha image

check out more details here

sur captcha, plugin, rails, ror, rubyonrails

Hello Everyone !!
I have released a captcha plugin Simple Captcha. It is really simple to implement, and provides a cool feature of multiple styles of images. Visit here for more explanation.

To implement captcha in RubyonRails, validates_captcha plugin can be a good option but a small customization i need with this plugin was to use it on some specific action and not to be validated the captcha field every time an instance of the model is saved or updated.
Here is a small work-around for its customization…
How to use customized captcha in RoR ?
Install the plugin validates_captcha in your rails application by running this command from the root of your application

ruby script/plugin install http://svn.2750flesk.com/validates_captcha

Make sure that you can now see the directory vedor/plugins/validates_captcha.

Now run these commands from your application root to make the image and data directories

  ruby script/generate captcha store_directory
  ruby script/generate captcha image_directory

Here is the complete API for the usage of this plugin. I am describing the same idea as given in this API but in a bit more specific means.

Lets consider a model User in which we will implement the captcha.
Add the following code in the file app/models/user.rb

  class User < ActiveRecord::Base

    validates_captcha :if => :request_captcha_validation?
    attr_accessor :request_captcha_validation

    def request_captcha_validation?
      (self.request_captcha_validation==true)? true : false
    end

  end

Handle View and Controller

Add the code in the view inside your existing form.

  <% c = prepare_captcha :type => :image -%>
  <%= captcha_hidden_field c, 'user' %>
  <%= captcha_image_tag c %>
  <%= captcha_label 'user', 'Type in the text from the image above' %>
  <%= captcha_text_field 'user' %>

Your controller will look like

  def save
    # the line in bold represents that you need captcha validation.
    # if captcha validation is not required then remove this line from your controller.
    @user = User.new(params[:user])
    @user.request_captcha_validation = true
    @user.save
  end

However image is too noisy and it contains repeated strings.
To improve the quality of images generated by the plugin validates_captcha visit Here.

sur captcha, image, rails, ror, validations

Hello Everyone !!
I have released a captcha plugin Simple Captcha. It is really simple to implement, and provides a cool feature of multiple styles of images. Visit here for more explanation.

Validates captcha is a good plugin to implement captcha in your rails application.
However i found that there is repetition of the string of the image and the quality of image is not that good. To get a good quality image and random string
something like this

replace the code of the file /vendor/plugins/validates_captcha/lib/captcha_challenge.rb with the following code…

require 'digest/sha1'

module AngryMidgetPluginsInc #:nodoc:

	# CaptchaChallenge
	class CaptchaChallenge

		include CaptchaConfig
		extend CaptchaConfig

		DEFAULT_TTL = 1200#Lifetime in seconds. Default is 20 minutes.

		attr_reader :id, :created_at
		attr_accessor :ttl

		def initialize(options = {}) #:nodoc:
			generate_id

			options = {
				:ttl => config['default_ttl'] || DEFAULT_TTL
			}.update(options)

			self.ttl = options[:ttl]
			@created_at = Time.now

			self.class.prune
		end

		# Implement in subclasses.
		def correct? #:nodoc:
			raise NotImplementedError
		end

	private

		def generate_id #:nodoc:
			self.id = Digest::SHA1.hexdigest(Time.now.to_s+rand.to_s)
		end

		def id=(i) #:nodoc:
			@id = i
		end

		def write_to_store #:nodoc:
			store.transaction{
				store[:captchas] = Array.new unless store.root?(:captchas)
				store[:captchas] << self
			}
		end

	class << self

		# Removes old instances from PStore
		def prune
			store.transaction{
				if store.root?(:captchas)
					store[:captchas].each_with_index{|c,i|
						if Time.now > c.created_at+c.ttl
							store[:captchas].delete_at(i)
						end
					}
				end
			}
		end#prune
	end#class << self

	end

	# A CAPTCHA challenge where an image with text is
	# generated. A human can read the text with relative
	# ease, while most robots can not. There are accessibility
	# problems with this challenge, though, as people
	# with reduced or no vision are unlikely to pass the test.
	class CaptchaImageChallenge < CaptchaChallenge

		WORDS = ‘gorilla costume, superman, banana bender, chuck norris, xray vision, ahoy me hearties,
				 chunky bacon, latex, rupert murdoch, clap your hands, year 2000,
				 sugar coated, coca cola, rastafarian, airbus a380′.split(/,s+/)
		DEFAULT_DIR = ‘captcha’#public/images/captcha
		WRITE_DIR = File.join(RAILS_ROOT, ‘public’, ‘images’)
		DEFAULT_FILETYPE = ‘jpg’

		attr_reader :image
		attr_accessor :string, :dir, :filename, :filetype

		# Creates an image challenge.
	  def initialize(options = {})
			super

			options = {
				:string => config['words'] ? config['words'][rand(config['words'].size)] : WORDS[rand(WORDS.size)],
				:dir => config['default_dir'] || DEFAULT_DIR,
				:filetype => config['default_filetype'] || DEFAULT_FILETYPE
			}.update(options)

            self.string = Digest::SHA1.hexdigest(Time.now.to_s)[0..4].upcase #options[:string]
            self.dir = options[:dir]
            self.filetype = options[:filetype]
            self.filename = options[:filename] || generate_filename
            write_to_store
          end

		# Generates the image.
		def generate(options = {})
			options = {
				:fontsize => 50,
				:padding => 20,
				:color => ‘#000′,
				:background => ‘#fff’,
				:fontweight => ‘bolw’,
				:rotate => true
			}.update(options)

			options[:fontweight] = case options[:fontweight]
				when ‘bold’ then 700
				else 400
			end

			#added
			text = Array.new
			0.upto(4) do |i|
				text[i] = Magick::Draw.new
				text[i].pointsize = options[:fontsize]
				text[i].font_weight = 600 #options[:fontweight]
				text[i].fill = ‘black’ #options[:color]
				text[i].gravity = Magick::CenterGravity
				text[i].rotation = (rand(2)==1 ? rand(30) : -rand(30)) if options[:rotate]
			end

                  metric = text[2].get_type_metrics(self.string)
                  #add bg
		  canvas = Magick::ImageList.new
		  fill = Magick::HatchFill.new(’white’,'black’)
		  x = metric.width+options[:padding]
		  y = metric.height+options[:padding]

		  #ADDING NOISE

		  img1 = Magick::Image.new(x,y,fill)
		  gc = Magick::Draw.new
		  gc.stroke_linejoin(’round’)
		  gc.stroke(’black’)
		  gc.stroke_width(1)
                  100.times do |i|
                    x1 = rand(x)
                    y1 = rand(y)
                    gc.circle(x1,y1,x1.next,y1)
                  end
                  gc.draw(img1)
                  canvas << img1
                  0.upto(4) do |i|
				canvas << Magick::Image.new(metric.width+options[:padding], metric.height+options[:padding]){
					self.background_color = ‘#000F’
					y_loc = rand(y)
				}.annotate(text[i], 0, 0, (i-2)*30, rand(y/4), self.string[i,1]) #.wave(5, 20)
		  end

		  canvas << Magick::Image.new(metric.width+options[:padding], metric.height+options[:padding]){
		    #changed
		    p = Magick::Pixel.from_color(options[:background])
		    p.opacity = Magick::MaxRGB
		    self.background_color = p
		  }  #.add_noise(Magick::LaplacianNoise)

			self.image = canvas.flatten_images.blur_image(1)
		end

		# Writes image to file.
		def write(dir = self.dir, filename = self.filename)
			self.image.write(File.join(WRITE_DIR, dir, filename))
		end

		# Determine if the supplied +string+ matches
		# that used when generating the image.
		def correct?(string)
			string.downcase == self.string.downcase
		end

		# The full path to the image file, relative
		# to <tt>public/images</tt>.
		def file_path
			File.join(dir,filename)
		end

	class << self

		# Deletes old image files. Also calls CaptchaChallenge.prune
		def prune
			store.transaction{
				if store.root?(:captchas)
					store[:captchas].each_with_index{|c,i|
						if Time.now > c.created_at+c.ttl
							if File.exists?(File.join(WRITE_DIR, c.file_path))
								begin
									File.unlink(File.join(WRITE_DIR, c.file_path))
								rescue Exception
								end
							end
						end
					}
				end
			}
			super
		end#prune
	end#class << self

	private

		def generate_filename #:nodoc:
			self.id+’.'+self.filetype
		end

		def image=(i) #:nodoc:
			@image = i
		end

	end

end

visit Here to view the customized use of the plugin validates_captcha in RoR.

sur captcha, image, rails