Check it out here

I am moving this blog to Expressica

and i would like to inform all the readers to update their feeds and bookmarks to the new url http://expressica.com .

On my new blog i am going to release a captcha plugin which is really very simple to implement. This plugin provides the functionality to add captcha based authentication in your rails applications.

It mainly features…

• Controller based captcha
• Model based captcha
• and the feature i like the most is multiple image styles

You can simply pass the name of the image style from the view and captcha will throw the random strings as the selected style of image. The images are clear enough to read by human and blurred and manipulated enough to protect from bots.
Example of the images …

• simply_red
• simply_green
• simply_blue
• embosed_silver
• distorted_black
• all_black
• charcoal_grey
• almost_invisible

Comments/Queries are welcome on this idea.

I will release this plugin very soon on Expressica.com

CHECK THIS OUT…

Four simple steps to make the tree working…

1. DOWNLOAD the sample application. (let me know if you are getting any error in downloading the application.)
2. Create a test database in mysql or modify the file /config/database.yml according to the database and user u need.
3. Run the command

   ajaxtree> rake db:migrate

   from the application root.

4. Run the application server by running

   ajaxtree> ruby script/server

   and watch the working tree at http://localhost:3000

Here we will discuss the javascript and ruby based encryptions for SHA-256 only.

Javascript Encryption in Ruby on Rails

If you need to encrypt the password at client side in ror or any other web-based form submission so that the real password string can not reach the server you can you can download the Javascript Encryption files from here. There is all collection of the javascript encryption files available in the above archive. You will not need all of them. Put the file sha256.js in the /public/javascripts/ directory of your rails application.
Now lets take the example of Reset Password where encryption is a must.
This is how you can make your view say reset_password.rhtml

<%= javascript_include_tag 'sha256' %>
<script type="text/javascript">
// <![CDATA[
  function hashPassword() {
  reg = new RegExp(/^(?=.*\d)(?=.*([a-z]|[A-Z]))([\x20-\x7E]){8,40}$/);
  if((reg.test($F('password')))&&($F('password')==$F('password_confirmation'))){
  document.reset_password.realpass.value = hex_sha256($F('password'));
  $('password_confirmation').value = '';
  $('password').value = '';
  Element.hide("reset_password");
  Element.show("updating");
  return true
  }
  else{
  $('errors_in_pass').innerHTML = "Password should match confirmation.<br />Password should contain at least one letter and one integer.<br />Password length should be 8 to 40 characters long.<br />";
  $('password_confirmation').value = '';
  $('password').value = '';
  return false
  }
  }
// ]]>
</script>
<h1>Change Password</h1>
<div style="display:none;" id="updating">Updating Password</div>
<div id = "reset_password">
<div style = "color:red" id = "errors_in_pass"><%= flash[:notice] %></div>
<% form_for :person, @person, :url => {:action => "reset_password"}, :html => {:name => "reset_password",:onsubmit => "return hashPassword()"} do |f| %>
<%= hidden_field_tag 'realpass' %>
        New Password
        <%= f.password_field :password, :id=>"password", :class => "field text", :value=>"" %>
	Confirm New Password
        <%= f.password_field :password_confirmation, :id=>"password_confirmation", :class => "field text", :value=>"" %>
	<%= f.submit_tag "Continue" %>
<% end %>
</div>

However it may possible that a user have disabled the javascript of the browser. In that case we will need to add the encryption at server side too. In rubyonrails we can easily handle the SHA256 encryption for let say password by adding the code

require "digest/sha2"

hashed_password = Digest::SHA256.hexdigest("password_string")

in an appropriate position in the controller.

Where exactly we should use Integration Testing ?
Whenever we need to test a series of functionalities which belongs to more than one controller , we should go for Integration Testing and not the Functional one.

Since the functional and unit testing are controller and model centric respectively, rails automatically creates the related functional and unit tests files. But as integrations testing is not confined in any criteria of a specific controller or model, we have to create the integrations file manually… Well, nothing is headache in rails. Its a simple pre-written script, all you need is to call that script with a name you like for whole story you wish to test in the integration test.

Here is a real example of Integration Test in Ruby on Rails

Considerations for test…
We will simply test

• signing in
• posting a new article
• deleting an article with xml_http_request (ajax post request)

Create the test file by running

ruby script/generate integration_test initial_features

Make sure that now you have the file /test/integration/initial_features_test.rb. Rails automatically appends _test at the end of the file name.

For god sake Lets start the testing now
Code for the file /test/integration/initial_features_test.rb

require "#{File.dirname(__FILE__)}/../test_helper"

class InitialFeaturesTest < ActionController::IntegrationTest
  fixtures :users, :articles

  def test_initial_features
     user = user_for_test
     user.try_to_signin
     user.signin
     user.post_an_article
     user.delete_an_article_with_xhr
  end

  def user_for_test
    open_session do |user|
      def user.try_to_signin
        assert_nil session[:user] # assert_session_has & _has_no have been deprecated
        get "user/signin"
        assert_response :success
        post "user/signin", :email=>"test failure string", :password=>"test failure string"
        assert_nil session[:user]
      end
      def user.signin
        assert_nil session[:user]
        user = users(:first)
        post "user/signin", :email=>user.email, :password=>user.password
        assert_not_nil session[:user]
        assert_response :redirect
        assert_redirected_to "articles/show"
        # now as the session is set once, we need not to signin again
      end
      def user.post_an_article
        get "articles/show"
        assert_response :success
        assert_template "articles/show"
        user = session[:user]
        articles_count = user.articles.length
        post_via_redirect "article/new", :title=>"Integration Tetsing in Rails", :description=>"another relishing rails feature"
        assert_template "articles/show"
        assert_equal articles_count.next, user.reload.articles.length
      end
      def user.delete_an_article_with_xhr
        user = session[:user]
        articles_count = user.articles.length
        xml_http_request "articles/delete", :id=>articles(:first).id
        assert_equal articles_count-1,user.reload.articles.length
      end
    end
  end

end

Although these are not that high level integration tests that rails can provide but its just an overview on the integration tests. I will explain them soon.

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.

Go FireFox !! Go Flock !!