First attempt at providing a 'what to update' section for Rails 3.1

railties/guides/source/3_1_release_notes.textile

@@ -21,6 +21,106 @@ Rails 3.1 requires Ruby 1.8.7 or higher. Support for all of the previous Ruby ve
 
 TIP: Note that Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition have these fixed since release 1.8.7-2010.02 though. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x jump on 1.9.2 for smooth sailing.
 
+h4. What to update in your apps
+
+The following changes are meant for upgrading your application to Rails 3.1.3, the latest 3.1.x version of Rails.
+
+h5. Gemfile
+
+Make the following changes to your +Gemfile+.
+
+<ruby>
+gem 'rails', '= 3.1.3'
+gem 'mysql2'
+
+# Needed for the new asset pipeline
+group :assets do
+  gem 'sass-rails',   "~> 3.1.5"
+  gem 'coffee-rails', "~> 3.1.1"
+  gem 'uglifier',     ">= 1.0.3"
+end
+
+# jQuery is the default JavaScript library in Rails 3.1
+gem 'jquery-rails'
+</ruby>
+
+h5. config/application.rb
+
+The asset pipeline requires the following additions:
+
+<ruby>
+config.assets.enabled = true
+config.assets.version = '1.0'
+</ruby>
+
+h5. config/environments/development.rb
+
+* Remove the RJS setting <tt>config.action_view.debug_rjs = true</tt>.
+
+* Add the following, if you enable the asset pipeline.
+
+<ruby>
+# Do not compress assets
+config.assets.compress = false
+
+# Expands the lines which load the assets
+config.assets.debug = true
+</ruby>
+
+h5. config/environments/production.rb
+
+* Again, most of the changes below are for the asset pipeline. You can read more about these in the "Asset Pipeline":asset_pipeline.html guide.
+
+<ruby>
+# Compress JavaScripts and CSS
+config.assets.compress = true
+
+# Don't fallback to assets pipeline if a precompiled asset is missed
+config.assets.compile = false
+
+# Generate digests for assets URLs
+config.assets.digest = true
+
+# Defaults to Rails.root.join("public/assets")
+# config.assets.manifest = YOUR_PATH
+
+# Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added)
+# config.assets.precompile += %w( search.js )
+
+
+# Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
+# config.force_ssl = true
+
+</ruby>
+
+h5. config/environments/test.rb
+
+<ruby>
+# Configure static asset server for tests with Cache-Control for performance
+config.serve_static_assets = true
+config.static_cache_control = "public, max-age=3600"
+</ruby>
+
+h5. config/initializers/wrap_parameters.rb
+
+* Add this file with the following contents, if you wish to wrap parameters into a nested hash. This is on by default in new applications.
+
+<ruby>
+# Be sure to restart your server when you modify this file.
+# This file contains settings for ActionController::ParamsWrapper which
+# is enabled by default.
+
+# Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
+ActiveSupport.on_load(:action_controller) do
+  wrap_parameters :format => [:json]
+end
+
+# Disable root element in JSON by default.
+ActiveSupport.on_load(:active_record) do
+  self.include_root_in_json = false
+end
+</ruby>
+
 h3. Creating a Rails 3.1 application
 
 <shell>