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1 files changed, 226 insertions, 16 deletions
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md index d7dbfccb76..7267ef1b4f 100644 --- a/guides/source/upgrading_ruby_on_rails.md +++ b/guides/source/upgrading_ruby_on_rails.md @@ -3,10 +3,12 @@ A Guide for Upgrading Ruby on Rails This guide provides steps to be followed when you upgrade your applications to a newer version of Ruby on Rails. These steps are also available in individual release guides. +-------------------------------------------------------------------------------- + General Advice -------------- -Before attempting to upgrade an existing application, you should be sure you have a good reason to upgrade. You need to balance out several factors: the need for new features, the increasing difficulty of finding support for old code, and your available time and skills, to name a few. +Before attempting to upgrade an existing application, you should be sure you have a good reason to upgrade. You need to balance several factors: the need for new features, the increasing difficulty of finding support for old code, and your available time and skills, to name a few. ### Test Coverage @@ -22,11 +24,191 @@ Rails generally stays close to the latest released Ruby version when it's releas TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. 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 straight to 1.9.3 for smooth sailing. +### The Rake Task + +Rails provides the `rails:update` rake task. After updating the Rails version +in the Gemfile, run this rake task. +This will help you with the creation of new files and changes of old files in a +interactive session. + +```bash +$ rake rails:update + identical config/boot.rb + exist config + conflict config/routes.rb +Overwrite /myapp/config/routes.rb? (enter "h" for help) [Ynaqdh] + force config/routes.rb + conflict config/application.rb +Overwrite /myapp/config/application.rb? (enter "h" for help) [Ynaqdh] + force config/application.rb + conflict config/environment.rb +... +``` + +Don't forget to review the difference, to see if there were any unexpected changes. + Upgrading from Rails 4.1 to Rails 4.2 ------------------------------------- -NOTE: This section is a work in progress. +NOTE: This section is a work in progress, please help to improve this by sending +a [pull request](https://github.com/rails/rails/edit/master/guides/source/upgrading_ruby_on_rails.md). + +### Web Console + +First, add `gem 'web-console', '~> 2.0'` to the `:development` group in your Gemfile and run `bundle install` (it won't have been included when you upgraded Rails). Once it's been installed, you can simply drop a reference to the console helper (i.e., `<%= console %>`) into any view you want to enable it for. A console will also be provided on any error page you view in your development environment. + +Additionally, you can tell Rails to automatically mount a VT100-compatible console on a predetermined path by setting the appropriate configuration flags in your development config: + +```ruby +# config/environments/development.rb + +config.web_console.automount = true +config.web_console.default_mount_path = '/terminal' # Optional, defaults to /console +``` + +### Responders + +`respond_with` and the class-level `respond_to` methods have been extracted to the `responders` gem. To use them, simply add `gem 'responders', '~> 2.0'` to your Gemfile. Calls to `respond_with` and `respond_to` (again, at the class level) will no longer work without having included the `responders` gem in your dependencies: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + respond_to :html, :json + + def show + @user = User.find(params[:id]) + respond_with @user + end +end +``` + +Instance-level `respond_to` is unaffected and does not require the additional gem: + +```ruby +# app/controllers/users_controller.rb + +class UsersController < ApplicationController + def show + @user = User.find(params[:id]) + respond_to do |format| + format.html + format.json { render json: @user } + end + end +end +``` + +See [#16526](https://github.com/rails/rails/pull/16526) for more details. + +### Error handling in transaction callbacks + +Currently, Active Record suppresses errors raised +within `after_rollback` or `after_commit` callbacks and only prints them to +the logs. In the next version, these errors will no longer be suppressed. +Instead, the errors will propagate normally just like in other Active +Record callbacks. + +When you define a `after_rollback` or `after_commit` callback, you +will receive a deprecation warning about this upcoming change. When +you are ready, you can opt into the new behavior and remove the +deprecation warning by adding following configuration to your +`config/application.rb`: + + config.active_record.raise_in_transactional_callbacks = true + +See [#14488](https://github.com/rails/rails/pull/14488) and +[#16537](https://github.com/rails/rails/pull/16537) for more details. + +### Ordering of test cases + +In Rails 5.0, test cases will be executed in random order by default. In +anticipation of this change, Rails 4.2 introduced a new configuration option +`active_support.test_order` for explicitly specifying the test ordering. This +allows you to either lock down the current behavior by setting the option to +`:sorted`, or opt into the future behavior by setting the option to `:random`. +If you do not specify a value for this option, a deprecation warning will be +emitted. To avoid this, add the following line to your test environment: + +```ruby +# config/environments/test.rb +Rails.application.configure do + config.active_support.test_order = :sorted # or `:random` if you prefer +end +``` + +### Serialized attributes + +When using a custom coder (e.g. `serialize :metadata, JSON`), +assigning `nil` to a serialized attribute will save it to the database +as `NULL` instead of passing the `nil` value through the coder (e.g. `"null"` +when using the `JSON` coder). + +### `after_bundle` in Rails templates + +If you have a Rails template that adds all the files in version control, it +fails to add the generated binstubs because it gets executed before Bundler: + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +git :init +git add: "." +git commit: %Q{ -m 'Initial commit' } +``` + +You can now wrap the `git` calls in an `after_bundle` block. It will be run +after the binstubs have been generated. + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +after_bundle do + git :init + git add: "." + git commit: %Q{ -m 'Initial commit' } +end +``` + +### Rails Html Sanitizer + +There's a new choice for sanitizing HTML fragments in your applications. The +venerable html-scanner approach is now officially being deprecated in favor of +[`Rails Html Sanitizer`](https://github.com/rails/rails-html-sanitizer). + +This means the methods `sanitize`, `sanitize_css`, `strip_tags` and +`strip_links` are backed by a new implementation. + +This new sanitizer uses [Loofah](https://github.com/flavorjones/loofah) internally. Loofah in turn uses Nokogiri, which +wraps XML parsers written in both C and Java, so sanitization should be faster +no matter which Ruby version you run. + +The new version updates `sanitize`, so it can take a `Loofah::Scrubber` for +powerful scrubbing. +[See some examples of scrubbers here](https://github.com/flavorjones/loofah#loofahscrubber). + +Two new scrubbers have also been added: `PermitScrubber` and `TargetScrubber`. +Read the [gem's readme](https://github.com/rails/rails-html-sanitizer) for more information. + +The documentation for `PermitScrubber` and `TargetScrubber` explains how you +can gain complete control over when and how elements should be stripped. + +If your application needs to old behaviour include `rails-deprecated_sanitizer` in your Gemfile: + +```ruby +gem 'rails-deprecated_sanitizer' +``` + +### Rails DOM Testing + +TODO: Mention https://github.com/rails/rails/commit/4e97d7585a2f4788b9eed98c6cdaf4bb6f2cf5ce Upgrading from Rails 4.0 to Rails 4.1 ------------------------------------- @@ -36,7 +218,7 @@ Upgrading from Rails 4.0 to Rails 4.1 Or, "whaaat my tests are failing!!!?" Cross-site request forgery (CSRF) protection now covers GET requests with -JavaScript responses, too. That prevents a third-party site from referencing +JavaScript responses, too. This prevents a third-party site from referencing your JavaScript URL and attempting to run it to extract sensitive data. This means that your functional and integration tests that use @@ -87,8 +269,8 @@ secrets, you need to: ``` 2. Use your existing `secret_key_base` from the `secret_token.rb` initializer to - set the SECRET_KEY_BASE environment variable for whichever users run the Rails - app in production mode. Alternately, you can simply copy the existing + set the SECRET_KEY_BASE environment variable for whichever users running the + Rails application in production mode. Alternatively, you can simply copy the existing `secret_key_base` from the `secret_token.rb` initializer to `secrets.yml` under the `production` section, replacing '<%= ENV["SECRET_KEY_BASE"] %>'. @@ -102,7 +284,7 @@ secrets, you need to: If your test helper contains a call to `ActiveRecord::Migration.check_pending!` this can be removed. The check -is now done automatically when you `require 'test_help'`, although +is now done automatically when you `require 'rails/test_help'`, although leaving this line in your helper is not harmful in any way. ### Cookies serializer @@ -216,6 +398,16 @@ If your application depends on one of these features, you can get them back by adding the [`activesupport-json_encoder`](https://github.com/rails/activesupport-json_encoder) gem to your Gemfile. +#### JSON representation of Time objects + +`#as_json` for objects with time component (`Time`, `DateTime`, `ActiveSupport::TimeWithZone`) +now returns millisecond precision by default. If you need to keep old behavior with no millisecond +precision, set the following in an initializer: + +``` +ActiveSupport::JSON::Encoding.time_precision = 0 +``` + ### Usage of `return` within inline callback blocks Previously, Rails allowed inline callback blocks to use `return` this way: @@ -271,7 +463,7 @@ included in the newly introduced `ActiveRecord::FixtureSet.context_class`, in `test_helper.rb`. ```ruby -class FixtureFileHelpers +module FixtureFileHelpers def file_sha(path) Digest::SHA2.hexdigest(File.read(Rails.root.join('test/fixtures', path))) end @@ -281,8 +473,8 @@ ActiveRecord::FixtureSet.context_class.send :include, FixtureFileHelpers ### I18n enforcing available locales -Rails 4.1 now defaults the I18n option `enforce_available_locales` to `true`, -meaning that it will make sure that all locales passed to it must be declared in +Rails 4.1 now defaults the I18n option `enforce_available_locales` to `true`. This +means that it will make sure that all locales passed to it must be declared in the `available_locales` list. To disable it (and allow I18n to accept *any* locale option) add the following @@ -292,9 +484,10 @@ configuration to your application: config.i18n.enforce_available_locales = false ``` -Note that this option was added as a security measure, to ensure user input could -not be used as locale information unless previously known, so it's recommended not -to disable this option unless you have a strong reason for doing so. +Note that this option was added as a security measure, to ensure user input +cannot be used as locale information unless it is previously known. Therefore, +it's recommended not to disable this option unless you have a strong reason for +doing so. ### Mutator methods called on Relation @@ -315,10 +508,10 @@ authors.compact! ### Changes on Default Scopes -Default scopes are no longer overriden by chained conditions. +Default scopes are no longer overridden by chained conditions. In previous versions when you defined a `default_scope` in a model -it was overriden by chained conditions in the same field. Now it +it was overridden by chained conditions in the same field. Now it is merged like any other scope. Before: @@ -402,11 +595,25 @@ Using `render :text` may pose a security risk, as the content is sent as ### PostgreSQL json and hstore datatypes Rails 4.1 will map `json` and `hstore` columns to a string-keyed Ruby `Hash`. -In earlier versions a `HashWithIndifferentAccess` was used. This means that +In earlier versions, a `HashWithIndifferentAccess` was used. This means that symbol access is no longer supported. This is also the case for `store_accessors` based on top of `json` or `hstore` columns. Make sure to use string keys consistently. +### Explicit block use for `ActiveSupport::Callbacks` + +Rails 4.1 now expects an explicit block to be passed when calling +`ActiveSupport::Callbacks.set_callback`. This change stems from +`ActiveSupport::Callbacks` being largely rewritten for the 4.1 release. + +```ruby +# Previously in Rails 4.0 +set_callback :save, :around, ->(r, &block) { stuff; result = block.call; stuff } + +# Now in Rails 4.1 +set_callback :save, :around, ->(r, block) { stuff; result = block.call; stuff } +``` + Upgrading from Rails 3.2 to Rails 4.0 ------------------------------------- @@ -478,7 +685,7 @@ being used, you can update your form to use the `PUT` method instead: <%= form_for [ :update_name, @user ], method: :put do |f| %> ``` -For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/25/edge-rails-patch-is-the-new-primary-http-method-for-updates/) +For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/26/edge-rails-patch-is-the-new-primary-http-method-for-updates/) on the Rails blog. #### A note about media types @@ -538,6 +745,9 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep * Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. You shouldn't use instance methods since it's now deprecated. You should change them to use class methods, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`. +* When using the default coder, assigning `nil` to a serialized attribute will save it +to the database as `NULL` instead of passing the `nil` value through YAML (`"--- \n...\n"`). + * Rails 4.0 has removed `attr_accessible` and `attr_protected` feature in favor of Strong Parameters. You can use the [Protected Attributes gem](https://github.com/rails/protected_attributes) for a smooth upgrade path. * If you are not using Protected Attributes, you can remove any options related to |