Rails upgrade from 2.3.5 to 3.0.9

Few weeks back I did rails upgrade for my current project from rails 2.3.5 to rails 3.0.9 (on Windows 7).

I began with rails 3 upgrade guide. So, first step was to install ruby 187, which I already had on my system with pik

There is a good series on rails on upgrading to rails 3 from Ryan Bates:
http://asciicasts.com/episodes/226-upgrading-to-rails-3-part-1
http://asciicasts.com/episodes/226-upgrading-to-rails-3-part-2
http://asciicasts.com/episodes/226-upgrading-to-rails-3-part-3

Some how the rails-upgrade-plugin did not work for me (as I was working on Windows 7) .

I then followed the-path-to-rails-3-approaching-the-upgrade step-by-step and I got application 80% upgraded, the rest 20% was a tough part.

In this blog, I am writing about challenges I faced in this process.

• Installing rails 3.0.9 gem:
  Somehow gem install rails shown errors:
  C:\myapp>gem install rails
  Successfully installed rails-3.0.9
  1 gem installed
  
  Installing ri documentation for rails-3.0.9...
  file 'lib' not found
  Installing RDoc documentation for rails-3.0.9...
  file 'lib' not found
  
  I used,
  C:\myapp>gem install rails --no-rdoc --no-riSuccessfully installed rails-3.0.9
  1 gem installed
  
• routes.rb
  I had to update the routes.rb file and I found one really helpful link: http://stackoverflow.com/questions/3103765/routing-in-rails-3-map-with-options
  
• Deprecation warning for cookie_store:
  DEPRECATION WARNING: ActionController::Base.session= is deprecated. Please configure it on your application with config.session_store :cookie_store, :key => '....'. (called from C:/myapp/config/initializers/session_store.rb:7)
  
  So, I did:
  module Myapp   class Application < Rails::Application     config.session_store :cookie_store, :key => '_myapp_session', :secret => 'some-secret-string-very-long'
  Also, I removed C:/myapp/config/initializers/session_store.rb file.
  Reference: http://stackoverflow.com/questions/3720379/sqlsessionstore-in-rails-3 and http://apidock.com/rails/ActiveRecord/SessionStore
  
• Logging the deprecation warnings
  I saw another warning:
  You did not specify how you would like Rails to report deprecation notices for your development environment, please set config.active_support.deprecation to :log at config/environments/development.rb
  
  So, I updated development.rb (and other .rb files):
  Myapp::Application.configure do     config.active_support.deprecation = :log
• consider_all_requests_local warning
  DEPRECATION WARNING: ActionController::Base.consider_all_requests_local= is deprecated. Please configure it on your application with config.consider_all_requests_local=.
  
  So, I added this snippet in config/environments/development.rb
  Myapp::Application.configure do config.consider_all_requests_local = true
• Some easy once
  1. DEPRECATION WARNING: RAILS_ENV is deprecated. Please use ::Rails.env.
  So, wherever I was using RAILS_ENV, I replaced with Rails.env
  
  2. DEPRECATION WARNING: RAILS_ROOT is deprecated. Please use ::Rails.root.to_s.
  So, wherever I was using RAILS_ROOT, I replaced with Rails.root.to_s
  
• ActionMailer warnings
  1. When you need to set character set for action mailer, you specify in initializer.rb, which throws this warning:
  DEPRECATION WARNING: ActionMailer::Base.default_charset=value is deprecated, use default :charset => value instead
  
  I passed hash to the default method in application.rb:
  Myapp::Application.configure do default :charset => 'utf-8'
  2 Similarly the mime version we set in initializers:
  DEPRECATION WARNING: ActionMailer::Base.default_mime_version=value is deprecated, use default :mime_version => value instead.
  
  I passed hash to the default method in application.rb:
  Myapp::Application.configure do default :mime_version => '1.0'

  3. For multipart emails the setting has to be adjusted:
  DEPRECATION WARNING: ActionMailer::Base.default_implicit_parts_order=value is deprecated, use default :implicit_parts_order => value instead
  This is again can be passed to default method:
  Myapp::Application.configure do   default :parts_order => [ "text/plain", "text/enriched", "text/html" ]

• html_safe in view?
  For 2-3 hours I struggled to find the reason, why the select tag was not producing the tags. When I found it I understand that this is again a security addition to convert strings into html safe form. So, all your '&lt;' will be converted to '<' and all '&gt;' will be converted into '>'. I actually added .html_safe at the end of each string in view and that showed all the tags finally.
  
  Reference: rails-3-select-tag-not-producing-dom-elements
  
• Removed config.action_view.cache_template_loading, use config.cache_classes instead
  Reference: https://github.com/rails/rails/commit/83e29b9773ac113ceacb1e36c2f333d692de2573
  
• Rspec
  I was using rspec and here is the deprecation warning I got:
  *****************************************************************
  DEPRECATION WARNING: you are using a deprecated constant that will be removed from a future version of RSpec.
  C:/cit/spec/controllers/activity_logs_controller_spec.rb:1:in `require'
  * Spec is deprecated.
  * RSpec is the new top-level module in RSpec-2
  ***************************************************************
  ***************************************************************
  DEPRECATION WARNING: you are using deprecated behaviour that will be removed from a future version of RSpec.
  C:/cit/spec/spec_helper.rb:17
  * Spec::Runner.configure is deprecated.
  * please use RSpec.configure instead.
  
  So, I have to use rspec-rails-2 which supports rails 3.
  Reference: http://groups.google.com/group/cukes/browse_thread/thread/40c4c2aea1c07afe/cb63eb7f0b733646?lnk=raot
  
• Ajax stopped working
  I was using jQuery as javascript library, and I found somehow the ajax calls stopped working after the upgrade. I later found that there is a security threat and a fix for that is available
  Here is what I had to do:
  
  Step#1. In application.html.erb, I had to include csrf_meta_tag:
  <%= javascript_include_tag :defaults %> <%= csrf_meta_tag %>
  Step#2. I added this snippet to application.js:
  $(document).ajaxSend(function(e, xhr, options) {   var token = $("meta[name='csrf-token']").attr("content");
  xhr.setRequestHeader("X-CSRF-Token", token); });
  
  Reference: csrf-protection-bypass-in-ruby-on-rails
  
• RackBaseURI instead of RailsBaseURI
  I was using RailsBaseURI in apache, but after upgrade to Rails 3, I had to update it to RackBaseURI
  Reference: RackBaseURI
  
• Last but not least, I was using valid? method in helper to check if the object is valid or not and based on that I was displaying certain fields, which was working fine in Rails 2.  In Rails 3 valid? method will trigger validations as well, which caused field_with_errors div to show-up all the time (even when the validation should not happen). I changed the logic to not use valid? method to display other fields and it solved the problem.