5 files changed, 104 insertions, 3 deletions
diff --git a/guides/CHANGELOG.md b/guides/CHANGELOG.md
index 99d69d5eda..dd5ca4b395 100644
--- a/guides/CHANGELOG.md
+++ b/guides/CHANGELOG.md
@@ -6,4 +6,8 @@
 
     *Andrey Nering*
 
+*   New section in Configuring: Search Engines Indexing
+
+    *Andrey Nering*
+
 Please check [4-2-stable](https://github.com/rails/rails/blob/4-2-stable/guides/CHANGELOG.md) for previous changes.
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 93f76d3bf7..de26a9bd6d 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -606,9 +606,7 @@ This helper validates that the attribute's value is unique right before the
 object gets saved. It does not create a uniqueness constraint in the database,
 so it may happen that two different database connections create two records
 with the same value for a column that you intend to be unique. To avoid that,
-you must create a unique index on both columns in your database. See
-[the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html)
-for more details about multiple column indexes.
+you must create a unique index on that column in your database.
 
 ```ruby
 class Account < ActiveRecord::Base
@@ -628,6 +626,7 @@ class Holiday < ActiveRecord::Base
     message: "should happen once per year" }
 end
 ```
+Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](http://www.postgresql.org/docs/9.4/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns.
 
 There is also a `:case_sensitive` option that you can use to define whether the
 uniqueness constraint will be case sensitive or not. This option defaults to
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 9c0f2ddc8a..994cc31cff 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -1049,3 +1049,21 @@ These configuration points are then available through the configuration object:
   Rails.configuration.x.super_debugger              # => true
   Rails.configuration.x.super_debugger.not_set      # => nil
   ```
+
+Search Engines Indexing
+-----------------------
+
+Sometimes, you may want to prevent some pages of your application be visible on search sites like Google,
+Bing, Yahoo or Duck Duck Go. The robots that index these sites will first analyse the
+`https://your-site.com/robots.txt` file to know what pages it is allowed to index.
+
+Rails creates this file for you on `/public` folder. By default, it allows search engines to index all
+pages of your application. If you want to block indexing on all pages of you application, use this:
+
+```
+User-agent: *
+Disallow: /
+```
+
+To block just specific pages, it's necessary to use a more complex syntax. Learn it on the
+[official documentation](http://www.robotstxt.org/robotstxt.html).
diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md
index a2d2e93e3b..6113a61f4c 100644
--- a/guides/source/debugging_rails_applications.md
+++ b/guides/source/debugging_rails_applications.md
@@ -242,6 +242,58 @@ The contents of the block, and therefore the string interpolation, is only
 evaluated if debug is enabled. This performance savings is only really
 noticeable with large amounts of logging, but it's a good practice to employ.
 
+
+Debugging with the `web-console` gem
+-------------------------------------
+
+The web console allows you to create an interactive ruby session in your browser. An interactive 
+console is launched automatically in case on an error but can also be launched for debugging purposes
+by invoking `console` in a view or controller.
+
+For example in a view:
+
+```ruby
+# new.html.erb
+<%= console %>
+```
+
+Or in a controller:
+
+```ruby
+# posts_controller.rb
+class PostsController < ApplicationController
+  def new
+    console
+    @post = Post.new
+  end
+end
+```
+###config.web_console.whitelisted_ips
+
+By default the web console can only be accessed from localhost. `config.web_console.whitelisted_ips` 
+lets you control which IPs have access to the console. 
+
+For example, to allow access from both localhost and 192.168.0.100:
+
+```ruby
+# config/application.rb
+class Application < Rails::Application
+  config.web_console.whitelisted_ips = %w( 127.0.0.1 192.168.0.100 )
+end
+```
+
+To allow access from an entire network:
+
+```ruby
+# config/application.rb
+class Application < Rails::Application
+  config.web_console.whitelisted_ips = %w( 127.0.0.1 192.168.0.0/16 )
+end
+```
+
+Web console is a powerful tool so be careful who you open access to.
+
+
 Debugging with the `byebug` gem
 ---------------------------------
 
diff --git a/guides/source/working_with_javascript_in_rails.md b/guides/source/working_with_javascript_in_rails.md
index f3d3a83afc..e3856a285a 100644
--- a/guides/source/working_with_javascript_in_rails.md
+++ b/guides/source/working_with_javascript_in_rails.md
@@ -191,6 +191,34 @@ $(document).ready ->
 Obviously, you'll want to be a bit more sophisticated than that, but it's a
 start. You can see more about the events [in the jquery-ujs wiki](https://github.com/rails/jquery-ujs/wiki/ajax).
 
+Another possibility is returning javascript directly from the server side on
+remote calls:
+
+```ruby
+# articles_controller
+def create
+  respond_to do |format|
+    if @article.save
+      format.html { ... }
+      format.js do
+        render js: <<-endjs
+          alert('Article saved successfully!');
+          window.location = '#{article_path(@article)}';
+        endjs
+      end
+    else
+      format.html { ... }
+      format.js do
+        render js: "alert('There are empty fields in the form!');"
+      end
+    end
+  end
+end
+```
+
+NOTE: If javascript is disabled in the user browser, `format.html { ... }`
+block should be executed as fallback.
+
 ### form_tag
 
 [`form_tag`](http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html#method-i-form_tag)