diff options
Diffstat (limited to 'guides/source/4_0_release_notes.md')
| -rw-r--r-- | guides/source/4_0_release_notes.md | 906 |
1 files changed, 148 insertions, 758 deletions
diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md index c909ef1496..c4ca1e921f 100644 --- a/guides/source/4_0_release_notes.md +++ b/guides/source/4_0_release_notes.md @@ -1,47 +1,28 @@ Ruby on Rails 4.0 Release Notes =============================== -Highlights in Rails 4.0: (WIP) +Highlights in Rails 4.0: -* Ruby 1.9.3 only +* Ruby 2.0 preferred; 1.9.3+ required * Strong Parameters -* Queue API -* Caching Improvements +* Turbolinks +* Russian Doll Caching -These release notes cover the major changes, but do not include each bug-fix and changes. If you want to see everything, check out the [list of commits](https://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. +These release notes cover only the major changes. To know about various bug fixes and changes, please refer to the change logs or check out the [list of commits](https://github.com/rails/rails/commits/master) in the main Rails repository on GitHub. -------------------------------------------------------------------------------- Upgrading to Rails 4.0 ---------------------- -TODO. This is a WIP guide. +If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 3.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 4.0. A list of things to watch out for when upgrading is available in the [Upgrading to Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to-rails-4-0) guide. -If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 3.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 4.0. Then take heed of the following changes: - -### Rails 4.0 requires at least Ruby 1.9.3 - -Rails 4.0 requires Ruby 1.9.3 or higher. Support for all of the previous Ruby versions has been dropped officially and you should upgrade as early as possible. - -### What to update in your apps - -* Update your Gemfile to depend on - * `rails = 4.0.0` - * `sass-rails ~> 3.2.3` - * `coffee-rails ~> 3.2.1` - * `uglifier >= 1.0.3` - -TODO: Update the versions above. - -* Rails 4.0 removes `vendor/plugins` completely. You have to replace these plugins by extracting them as gems and adding them in your Gemfile. If you choose not to make them gems, you can move them into, say, `lib/my_plugin/*` and add an appropriate initializer in `config/initializers/my_plugin.rb`. - -TODO: Configuration changes in environment files Creating a Rails 4.0 application -------------------------------- ``` - You should have the 'rails' rubygem installed + You should have the 'rails' RubyGem installed $ rails new myapp $ cd myapp ``` @@ -69,816 +50,225 @@ $ ruby /path/to/rails/railties/bin/rails new myapp --dev Major Features -------------- +[](http://guides.rubyonrails.org/images/rails4_features.png) + +### Upgrade + + * **Ruby 1.9.3** ([commit](https://github.com/rails/rails/commit/a0380e808d3dbd2462df17f5d3b7fcd8bd812496)) - Ruby 2.0 preferred; 1.9.3+ required + * **[New deprecation policy](http://www.youtube.com/watch?v=z6YgD6tVPQs)** - Deprecated features are warnings in Rails 4.0 and will be removed in Rails 4.1. + * **ActionPack page and action caching** ([commit](https://github.com/rails/rails/commit/b0a7068564f0c95e7ef28fc39d0335ed17d93e90)) - Page and action caching are extracted to a separate gem. Page and action caching requires too much manual intervention (manually expiring caches when the underlying model objects are updated). Instead, use Russian doll caching. + * **ActiveRecord observers** ([commit](https://github.com/rails/rails/commit/ccecab3ba950a288b61a516bf9b6962e384aae0b)) - Observers are extracted to a separate gem. Observers are only needed for page and action caching, and can lead to spaghetti code. + * **ActiveRecord session store** ([commit](https://github.com/rails/rails/commit/0ffe19056c8e8b2f9ae9d487b896cad2ce9387ad)) - The ActiveRecord session store is extracted to a separate gem. Storing sessions in SQL is costly. Instead, use cookie sessions, memcache sessions, or a custom session store. + * **ActiveModel mass assignment protection** ([commit](https://github.com/rails/rails/commit/f8c9a4d3e88181cee644f91e1342bfe896ca64c6)) - Rails 3 mass assignment protection is deprecated. Instead, use strong parameters. + * **ActiveResource** ([commit](https://github.com/rails/rails/commit/f1637bf2bb00490203503fbd943b73406e043d1d)) - ActiveResource is extracted to a separate gem. ActiveResource was not widely used. + * **vendor/plugins removed** ([commit](https://github.com/rails/rails/commit/853de2bd9ac572735fa6cf59fcf827e485a231c3)) - Use a Gemfile to manage installed gems. + +### ActionPack + + * **Strong parameters** ([commit](https://github.com/rails/rails/commit/a8f6d5c6450a7fe058348a7f10a908352bb6c7fc)) - Only allow whitelisted parameters to update model objects (`params.permit(:title, :text)`). + * **Routing concerns** ([commit](https://github.com/rails/rails/commit/0dd24728a088fcb4ae616bb5d62734aca5276b1b)) - In the routing DSL, factor out common subroutes (`comments` from `/posts/1/comments` and `/videos/1/comments`). + * **ActionController::Live** ([commit](https://github.com/rails/rails/commit/af0a9f9eefaee3a8120cfd8d05cbc431af376da3)) - Stream JSON with `response.stream`. + * **Declarative ETags** ([commit](https://github.com/rails/rails/commit/ed5c938fa36995f06d4917d9543ba78ed506bb8d)) - Add controller-level etag additions that will be part of the action etag computation + * **[Russian doll caching](http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works)** ([commit](https://github.com/rails/rails/commit/4154bf012d2bec2aae79e4a49aa94a70d3e91d49)) - Cache nested fragments of views. Each fragment expires based on a set of dependencies (a cache key). The cache key is usually a template version number and a model object. + * **Turbolinks** ([commit](https://github.com/rails/rails/commit/e35d8b18d0649c0ecc58f6b73df6b3c8d0c6bb74)) - Serve only one initial HTML page. When the user navigates to another page, use pushState to update the URL and use AJAX to update the title and body. + * **Decouple ActionView from ActionController** ([commit](https://github.com/rails/rails/commit/78b0934dd1bb84e8f093fb8ef95ca99b297b51cd)) - ActionView was decoupled from ActionPack and will be moved to a separated gem in Rails 4.1. + * **Do not depend on ActiveModel** ([commit](https://github.com/rails/rails/commit/166dbaa7526a96fdf046f093f25b0a134b277a68)) - ActionPack no longer depends on ActiveModel. + +### General + + * **ActiveModel::Model** ([commit](https://github.com/rails/rails/commit/3b822e91d1a6c4eab0064989bbd07aae3a6d0d08)) - `ActiveModel::Model`, a mixin to make normal Ruby objects to work with ActionPack out of box (ex. for `form_for`) + * **New scope API** ([commit](https://github.com/rails/rails/commit/50cbc03d18c5984347965a94027879623fc44cce)) - Scopes must always use callables. + * **Schema cache dump** ([commit](https://github.com/rails/rails/commit/5ca4fc95818047108e69e22d200e7a4a22969477)) - To improve Rails boot time, instead of loading the schema directly from the database, load the schema from a dump file. + * **Support for specifying transaction isolation level** ([commit](https://github.com/rails/rails/commit/392eeecc11a291e406db927a18b75f41b2658253)) - Choose whether repeatable reads or improved performance (less locking) is more important. + * **Dalli** ([commit](https://github.com/rails/rails/commit/82663306f428a5bbc90c511458432afb26d2f238)) - Use Dalli memcache client for the memcache store. + * **Notifications start & finish** ([commit](https://github.com/rails/rails/commit/f08f8750a512f741acb004d0cebe210c5f949f28)) - Active Support instrumentation reports start and finish notifications to subscribers. + * **Thread safe by default** ([commit](https://github.com/rails/rails/commit/5d416b907864d99af55ebaa400fff217e17570cd)) - Rails can run in threaded app servers without additional configuration. Note: Check that the gems you are using are threadsafe. + * **PATCH verb** ([commit](https://github.com/rails/rails/commit/eed9f2539e3ab5a68e798802f464b8e4e95e619e)) - In Rails, PATCH replaces PUT. PATCH is used for partial updates of resources. + +### Security + + * **match do not catch all** ([commit](https://github.com/rails/rails/commit/90d2802b71a6e89aedfe40564a37bd35f777e541)) - In the routing DSL, match requires the HTTP verb or verbs to be specified. + * **html entities escaped by default** ([commit](https://github.com/rails/rails/commit/5f189f41258b83d49012ec5a0678d827327e7543)) - Strings rendered in erb are escaped unless wrapped with `raw` or `html_safe` is called. + * **New security headers** ([commit](https://github.com/rails/rails/commit/6794e92b204572d75a07bd6413bdae6ae22d5a82)) - Rails sends the following headers with every HTTP request: `X-Frame-Options` (prevents clickjacking by forbidding the browser from embedding the page in a frame), `X-XSS-Protection` (asks the browser to halt script injection) and `X-Content-Type-Options` (prevents the browser from opening a jpeg as an exe). + +Extraction of features to gems +--------------------------- + +In Rails 4.0, several features have been extracted into gems. You can simply add the extracted gems to your `Gemfile` to bring the functionality back. + +* Hash-based & Dynamic finder methods ([GitHub](https://github.com/rails/activerecord-deprecated_finders)) +* Mass assignment protection in Active Record models ([GitHub](https://github.com/rails/protected_attributes), [Pull Request](https://github.com/rails/rails/pull/7251)) +* ActiveRecord::SessionStore ([GitHub](https://github.com/rails/activerecord-session_store), [Pull Request](https://github.com/rails/rails/pull/7436)) +* Active Record Observers ([GitHub](https://github.com/rails/rails-observers), [Commit](https://github.com/rails/rails/commit/39e85b3b90c58449164673909a6f1893cba290b2)) +* Active Resource ([GitHub](https://github.com/rails/activeresource), [Pull Request](https://github.com/rails/rails/pull/572), [Blog](http://yetimedia.tumblr.com/post/35233051627/activeresource-is-dead-long-live-activeresource)) +* Action Caching ([GitHub](https://github.com/rails/actionpack-action_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) +* Page Caching ([GitHub](https://github.com/rails/actionpack-page_caching), [Pull Request](https://github.com/rails/rails/pull/7833)) +* Sprockets ([GitHub](https://github.com/rails/sprockets-rails)) +* Performance tests ([GitHub](https://github.com/rails/rails-perftest), [Pull Request](https://github.com/rails/rails/pull/8876)) + Documentation ------------- * Guides are rewritten in GitHub Flavored Markdown. +* Guides have a responsive design. + Railties -------- -* Allow scaffold/model/migration generators to accept a `polymorphic` modifier for `references`/`belongs_to`, for instance - - ``` - rails g model Product supplier:references{polymorphic} - ``` - - will generate the model with `belongs_to :supplier, polymorphic: true` association and appropriate migration. - -* Set `config.active_record.migration_error` to `:page_load` for development. - -* Add runner to `Rails::Railtie` as a hook called just after runner starts. - -* Add `/rails/info/routes` path which displays the same information as `rake routes`. - -* Improved `rake routes` output for redirects. - -* Load all environments available in `config.paths["config/environments"]`. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/railties/CHANGELOG.md) for detailed changes. -* Add `config.queue_consumer` to change the job queue consumer from the default `ActiveSupport::ThreadedQueueConsumer`. +### Notable changes -* Add `Rails.queue` for processing jobs in the background. +* New test locations `test/models`, `test/helpers`, `test/controllers`, and `test/mailers`. Corresponding rake tasks added as well. ([Pull Request](https://github.com/rails/rails/pull/7878)) -* Remove `Rack::SSL` in favour of `ActionDispatch::SSL`. +* Your app's executables now live in the `bin/` directory. Run `rake rails:update:bin` to get `bin/bundle`, `bin/rails`, and `bin/rake`. -* Allow to set class that will be used to run as a console, other than IRB, with `Rails.application.config.console=`. It's best to add it to console block. +* Threadsafe on by default - ```ruby - # it can be added to config/application.rb - console do - # this block is called only when running console, - # so we can safely require pry here - require "pry" - config.console = Pry - end - ``` - -* Add a convenience method `hide!` to Rails generators to hide the current generator namespace from showing when running `rails generate`. - -* Scaffold now uses `content_tag_for` in `index.html.erb`. - -* `Rails::Plugin` is removed. Instead of adding plugins to `vendor/plugins`, use gems or bundler with path or git dependencies. +* Ability to use a custom builder by passing `--builder` (or `-b`) to + `rails new` has been removed. Consider using application templates + instead. ([Pull Request](https://github.com/rails/rails/pull/9401)) ### Deprecations -Action Mailer -------------- - -* Allow to set default Action Mailer options via `config.action_mailer.default_options=`. - -* Raise an `ActionView::MissingTemplate` exception when no implicit template could be found. - -* Asynchronously send messages via the Rails Queue. - -* Delivery Options (such as SMTP Settings) can now be set dynamically per mailer action. - - Delivery options are set via <tt>:delivery_method_options</tt> key on mail. - - ```ruby - def welcome_mailer(user,company) - delivery_options = { user_name: company.smtp_user, password: company.smtp_password, address: company.smtp_host } - mail(to: user.email, subject: "Welcome!", delivery_method_options: delivery_options) - end - ``` - -* Allow for callbacks in mailers similar to ActionController::Base. You can now set up headers/attachments using `before_filter` or `after_filter`. You could also change delivery settings or prevent delivery in an after filter based on instance variables set in your mailer action. You have access to `ActionMailer::Base` instance methods like `message`, `attachments`, `headers`. - -Action Pack ------------ - -### Action Controller - -* Add `ActionController::Flash.add_flash_types` method to allow people to register their own flash types. e.g.: - - ```ruby - class ApplicationController - add_flash_types :error, :warning - end - ``` - - If you add the above code, you can use `<%= error %>` in an erb, and `redirect_to /foo, :error => 'message'` in a controller. - -* Remove Active Model dependency from Action Pack. - -* Support unicode characters in routes. Route will be automatically escaped, so instead of manually escaping: - - ```ruby - get Rack::Utils.escape('こんにちは') => 'home#index' - ``` - - You just have to write the unicode route: - - ```ruby - get 'こんにちは' => 'home#index' - ``` - -* Return proper format on exceptions. - -* Extracted redirect logic from `ActionController::ForceSSL::ClassMethods.force_ssl` into `ActionController::ForceSSL#force_ssl_redirect`. - -* URL path parameters with invalid encoding now raise `ActionController::BadRequest`. - -* Malformed query and request parameter hashes now raise `ActionController::BadRequest`. - -* `respond_to` and `respond_with` now raise `ActionController::UnknownFormat` instead of directly returning head 406. The exception is rescued and converted to 406 in the exception handling middleware. - -* JSONP now uses `application/javascript` instead of `application/json` as the MIME type. - -* Session arguments passed to process calls in functional tests are now merged into the existing session, whereas previously they would replace the existing session. This change may break some existing tests if they are asserting the exact contents of the session but should not break existing tests that only assert individual keys. - -* Forms of persisted records use always PATCH (via the `_method` hack). - -* For resources, both PATCH and PUT are routed to the `update` action. - -* Don't ignore `force_ssl` in development. This is a change of behavior - use an `:if` condition to recreate the old behavior. - - ```ruby - class AccountsController < ApplicationController - force_ssl :if => :ssl_configured? - - def ssl_configured? - !Rails.env.development? - end - end - ``` - -#### Deprecations - -* Deprecated `ActionController::Integration` in favour of `ActionDispatch::Integration`. - -* Deprecated `ActionController::IntegrationTest` in favour of `ActionDispatch::IntegrationTest`. - -* Deprecated `ActionController::PerformanceTest` in favour of `ActionDispatch::PerformanceTest`. - -* Deprecated `ActionController::AbstractRequest` in favour of `ActionDispatch::Request`. - -* Deprecated `ActionController::Request` in favour of `ActionDispatch::Request`. - -* Deprecated `ActionController::AbstractResponse` in favour of `ActionDispatch::Response`. - -* Deprecated `ActionController::Response` in favour of `ActionDispatch::Response`. - -* Deprecated `ActionController::Routing` in favour of `ActionDispatch::Routing`. - -### Action Dispatch - -* Add Routing Concerns to declare common routes that can be reused inside others resources and routes. - - Code before: - - ```ruby - resources :messages do - resources :comments - end - - resources :posts do - resources :comments - resources :images, only: :index - end - ``` - - Code after: - - ```ruby - concern :commentable do - resources :comments - end - - concern :image_attachable do - resources :images, only: :index - end - - resources :messages, concerns: :commentable - - resources :posts, concerns: [:commentable, :image_attachable] - ``` - -* Show routes in exception page while debugging a `RoutingError` in development. - -* Include `mounted_helpers` (helpers for accessing mounted engines) in `ActionDispatch::IntegrationTest` by default. - -* Added `ActionDispatch::SSL` middleware that when included force all the requests to be under HTTPS protocol. - -* Copy literal route constraints to defaults so that url generation know about them. The copied constraints are `:protocol`, `:subdomain`, `:domain`, `:host` and `:port`. - -* Allows `assert_redirected_to` to match against a regular expression. - -* Adds a backtrace to the routing error page in development. - -* `assert_generates`, `assert_recognizes`, and `assert_routing` all raise `Assertion` instead of `RoutingError`. - -* Allows the route helper root to take a string argument. For example, `root 'pages#main'` as a shortcut for `root to: 'pages#main'`. - -* Adds support for the PATCH verb: Request objects respond to `patch?`. Routes now have a new `patch` method, and understand `:patch` in the existing places where a verb is configured, like `:via`. Functional tests have a new method `patch` and integration tests have a new method `patch_via_redirect`. -If `:patch` is the default verb for updates, edits are tunneled as `PATCH` rather than as `PUT` and routing acts accordingly. - -* Integration tests support the OPTIONS method. - -* `expires_in` accepts a `must_revalidate` flag. If true, "must-revalidate" is added to the `Cache-Control` header. - -* Default responder will now always use your overridden block in `respond_with` to render your response. - -* Turn off verbose mode of `rack-cache`, we still have `X-Rack-Cache` to check that info. - -#### Deprecations - -### Action View - -* Remove Active Model dependency from Action Pack. - -* Allow to use `mounted_helpers` (helpers for accessing mounted engines) in `ActionView::TestCase`. - -* Make current object and counter (when it applies) variables accessible when rendering templates with `:object` or `:collection`. - -* Allow to lazy load `default_form_builder` by passing a string instead of a constant. - -* Add index method to `FormBuilder` class. - -* Adds support for layouts when rendering a partial with a given collection. - -* Remove `:disable_with` in favor of `data-disable-with` option from `submit_tag`, `button_tag` and `button_to` helpers. - -* Remove `:mouseover` option from `image_tag` helper. - -* Templates without a handler extension now raises a deprecation warning but still defaults to `ERb`. In future releases, it will simply return the template content. - -* Add a `divider` option to `grouped_options_for_select` to generate a separator optgroup automatically, and deprecate prompt as third argument, in favor of using an options hash. - -* Add `time_field` and `time_field_tag` helpers which render an `input[type="time"]` tag. - -* Removed old `text_helper` apis for `highlight`, `excerpt` and `word_wrap`. - -* Remove the leading \n added by textarea on `assert_select`. - -* Changed default value for `config.action_view.embed_authenticity_token_in_remote_forms` to false. This change breaks remote forms that need to work also without JavaScript, so if you need such behavior, you can either set it to true or explicitly pass `:authenticity_token => true` in form options. - -* Make possible to use a block in `button_to` helper if button text is hard to fit into the name parameter: - - ```ruby - <%= button_to [:make_happy, @user] do %> - Make happy <strong><%= @user.name %></strong> - <% end %> - # => "<form method="post" action="/users/1/make_happy" class="button_to"> - # <div> - # <button type="submit"> - # Make happy <strong>Name</strong> - # </button> - # </div> - # </form>" - ``` - -* Replace `include_seconds` boolean argument with `:include_seconds => true` option in `distance_of_time_in_words` and `time_ago_in_words` signature. - -* Remove `button_to_function` and `link_to_function` helpers. - -* `truncate` now always returns an escaped HTML-safe string. The option `:escape` can be used as `false` to not escape the result. - -* `truncate` now accepts a block to show extra content when the text is truncated. - -* Add `week_field`, `week_field_tag`, `month_field`, `month_field_tag`, `datetime_local_field`, `datetime_local_field_tag`, `datetime_field` and `datetime_field_tag` helpers. - -* Add `color_field` and `color_field_tag` helpers. - -* Add `include_hidden` option to select tag. With `:include_hidden => false` select with multiple attribute doesn't generate hidden input with blank value. - -* Removed default size option from the `text_field`, `search_field`, `telephone_field`, `url_field`, `email_field` helpers. - -* Removed default cols and rows options from the `text_area` helper. - -* Adds `image_url`, `javascript_url`, `stylesheet_url`, `audio_url`, `video_url`, and `font_url` to assets tag helper. These URL helpers will return the full path to your assets. This is useful when you are going to reference this asset from external host. - -* Allow `value_method` and `text_method` arguments from `collection_select` and `options_from_collection_for_select` to receive an object that responds to `:call` such as a proc, to evaluate the option in the current element context. This works the same way with `collection_radio_buttons` and `collection_check_boxes`. - -* Add `date_field` and `date_field_tag` helpers which render an `input[type="date"]` tag. - -* Add `collection_check_boxes` form helper, similar to `collection_select`: - - ```ruby - collection_check_boxes :post, :author_ids, Author.all, :id, :name - # Outputs something like: - <input id="post_author_ids_1" name="post[author_ids][]" type="checkbox" value="1" /> - <label for="post_author_ids_1">D. Heinemeier Hansson</label> - <input id="post_author_ids_2" name="post[author_ids][]" type="checkbox" value="2" /> - <label for="post_author_ids_2">D. Thomas</label> - <input name="post[author_ids][]" type="hidden" value="" /> - ``` - - The label/check_box pairs can be customized with a block. - -* Add `collection_radio_buttons` form helper, similar to `collection_select`: - - ```ruby - collection_radio_buttons :post, :author_id, Author.all, :id, :name - # Outputs something like: - <input id="post_author_id_1" name="post[author_id]" type="radio" value="1" /> - <label for="post_author_id_1">D. Heinemeier Hansson</label> - <input id="post_author_id_2" name="post[author_id]" type="radio" value="2" /> - <label for="post_author_id_2">D. Thomas</label> - ``` - - The label/radio_button pairs can be customized with a block. - -* `check_box` with an HTML5 attribute `:form` will now replicate the `:form` attribute to the hidden field as well. - -* label form helper accepts `:for => nil` to not generate the attribute. - -* Add `:format` option to `number_to_percentage`. - -* Add `config.action_view.logger` to configure logger for `Action View`. - -* `check_box` helper with `:disabled => true` will generate a `disabled` hidden field to conform with the HTML convention where disabled fields are not submitted with the form. This is a behavior change, previously the hidden tag had a value of the disabled checkbox. - -* `favicon_link_tag` helper will now use the favicon in `app/assets` by default. +* `config.threadsafe!` is deprecated in favor of `config.eager_load` which provides a more fine grained control on what is eager loaded. -* `ActionView::Helpers::TextHelper#highlight` now defaults to the HTML5 `mark` element. +* `Rails::Plugin` has gone. Instead of adding plugins to `vendor/plugins` use gems or bundler with path or git dependencies. -#### Deprecations - -### Sprockets - -Moved into a separate gem `sprockets-rails`. - -Active Record +Action Mailer ------------- -* Add `add_reference` and `remove_reference` schema statements. Aliases, `add_belongs_to` and `remove_belongs_to` are acceptable. References are reversible. - - ```ruby - # Create a user_id column - add_reference(:products, :user) - - # Create a supplier_id, supplier_type columns and appropriate index - add_reference(:products, :supplier, polymorphic: true, index: true) - - # Remove polymorphic reference - remove_reference(:products, :supplier, polymorphic: true) - ``` - -* Add `:default` and `:null` options to `column_exists?`. - - ```ruby - column_exists?(:testings, :taggable_id, :integer, null: false) - column_exists?(:testings, :taggable_type, :string, default: 'Photo') - ``` - -* `ActiveRecord::Relation#inspect` now makes it clear that you are dealing with a `Relation` object rather than an array: - - ```ruby - User.where(:age => 30).inspect - # => <ActiveRecord::Relation [#<User ...>, #<User ...>]> - - User.where(:age => 30).to_a.inspect - # => [#<User ...>, #<User ...>] - ``` - - if more than 10 items are returned by the relation, inspect will only show the first 10 followed by ellipsis. - -* Add `:collation` and `:ctype` support to PostgreSQL. These are available for PostgreSQL 8.4 or later. - - ```yaml - development: - adapter: postgresql - host: localhost - database: rails_development - username: foo - password: bar - encoding: UTF8 - collation: ja_JP.UTF8 - ctype: ja_JP.UTF8 - ``` - -* `FinderMethods#exists?` now returns `false` with the `false` argument. - -* Added support for specifying the precision of a timestamp in the postgresql adapter. So, instead of having to incorrectly specify the precision using the `:limit` option, you may use `:precision`, as intended. For example, in a migration: - - ```ruby - def change - create_table :foobars do |t| - t.timestamps :precision => 0 - end - end - ``` - -* Allow `ActiveRecord::Relation#pluck` to accept multiple columns. Returns an array of arrays containing the typecasted values: - - ```ruby - Person.pluck(:id, :name) - # SELECT people.id, people.name FROM people - # => [[1, 'David'], [2, 'Jeremy'], [3, 'Jose']] - ``` - -* Improve the derivation of HABTM join table name to take account of nesting. It now takes the table names of the two models, sorts them lexically and then joins them, stripping any common prefix from the second table name. Some examples: - - ``` - Top level models (Category <=> Product) - Old: categories_products - New: categories_products - - Top level models with a global table_name_prefix (Category <=> Product) - Old: site_categories_products - New: site_categories_products - - Nested models in a module without a table_name_prefix method (Admin::Category <=> Admin::Product) - Old: categories_products - New: categories_products - - Nested models in a module with a table_name_prefix method (Admin::Category <=> Admin::Product) - Old: categories_products - New: admin_categories_products - - Nested models in a parent model (Catalog::Category <=> Catalog::Product) - Old: categories_products - New: catalog_categories_products - - Nested models in different parent models (Catalog::Category <=> Content::Page) - Old: categories_pages - New: catalog_categories_content_pages - ``` - -* Move HABTM validity checks to `ActiveRecord::Reflection`. One side effect of this is to move when the exceptions are raised from the point of declaration to when the association is built. This is consistant with other association validity checks. - -* Added `stored_attributes` hash which contains the attributes stored using `ActiveRecord::Store`. This allows you to retrieve the list of attributes you've defined. - - ```ruby - class User < ActiveRecord::Base - store :settings, accessors: [:color, :homepage] - end - - User.stored_attributes[:settings] # [:color, :homepage] - ``` - -* PostgreSQL default log level is now 'warning', to bypass the noisy notice messages. You can change the log level using the `min_messages` option available in your `config/database.yml`. - -* Add uuid datatype support to PostgreSQL adapter. - -* Added `ActiveRecord::Migration.check_pending!` that raises an error if migrations are pending. - -* Added `#destroy!` which acts like `#destroy` but will raise an `ActiveRecord::RecordNotDestroyed` exception instead of returning `false`. - -* Allow blocks for count with `ActiveRecord::Relation`, to work similar as `Array#count`: `Person.where("age > 26").count { |person| person.gender == 'female' }` - -* Added support to `CollectionAssociation#delete` for passing fixnum or string values as record ids. This finds the records responding to the ids and deletes them. - - ```ruby - class Person < ActiveRecord::Base - has_many :pets - end - - person.pets.delete("1") # => [#<Pet id: 1>] - person.pets.delete(2, 3) # => [#<Pet id: 2>, #<Pet id: 3>] - ``` - -* It's not possible anymore to destroy a model marked as read only. - -* Added ability to `ActiveRecord::Relation#from` to accept other `ActiveRecord::Relation` objects. - -* Added custom coders support for `ActiveRecord::Store`. Now you can set your custom coder like this: - - ```ruby - store :settings, accessors: [ :color, :homepage ], coder: JSON - ``` - -* `mysql` and `mysql2` connections will set `SQL_MODE=STRICT_ALL_TABLES` by default to avoid silent data loss. This can be disabled by specifying `strict: false` in `config/database.yml`. - -* Added default order to `ActiveRecord::Base#first` to assure consistent results among different database engines. Introduced `ActiveRecord::Base#take` as a replacement to the old behavior. - -* Added an `:index` option to automatically create indexes for `references` and `belongs_to` statements in migrations. This can be either a boolean or a hash that is identical to options available to the `add_index` method: - - ```ruby - create_table :messages do |t| - t.references :person, :index => true - end - ``` - - Is the same as: - - ```ruby - create_table :messages do |t| - t.references :person - end - add_index :messages, :person_id - ``` - - Generators have also been updated to use the new syntax. - -* Added bang methods for mutating `ActiveRecord::Relation` objects. For example, while `foo.where(:bar)` will return a new object leaving foo unchanged, `foo.where!(:bar)` will mutate the foo object. - -* Added `#find_by` and `#find_by!` to mirror the functionality provided by dynamic finders in a way that allows dynamic input more easily: - - ```ruby - Post.find_by name: 'Spartacus', rating: 4 - Post.find_by "published_at < ?", 2.weeks.ago - Post.find_by! name: 'Spartacus' - ``` - -* Added `ActiveRecord::Base#slice` to return a hash of the given methods with their names as keys and returned values as values. - -* Remove IdentityMap - IdentityMap has never graduated to be an "enabled-by-default" feature, due to some inconsistencies with associations, as described in this [commit](https://github.com/rails/rails/commit/302c912bf6bcd0fa200d964ec2dc4a44abe328a6). Hence the removal from the codebase, until such issues are fixed. - -* Added a feature to dump/load internal state of `SchemaCache` instance because we want to boot more quickly when we have many models. - - ```ruby - # execute rake task. - RAILS_ENV=production bundle exec rake db:schema:cache:dump - => generate db/schema_cache.dump - - # add config.use_schema_cache_dump = true in config/production.rb. BTW, true is default. - - # boot rails. - RAILS_ENV=production bundle exec rails server - => use db/schema_cache.dump - - # If you remove clear dumped cache, execute rake task. - RAILS_ENV=production bundle exec rake db:schema:cache:clear - => remove db/schema_cache.dump - ``` - -* Added support for partial indices to `PostgreSQL` adapter. - -* The `add_index` method now supports a `where` option that receives a string with the partial index criteria. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionmailer/CHANGELOG.md) for detailed changes. -* Added the `ActiveRecord::NullRelation` class implementing the null object pattern for the Relation class. - -* Implemented `ActiveRecord::Relation#none` method which returns a chainable relation with zero records (an instance of the `NullRelation` class). Any subsequent condition chained to the returned relation will continue generating an empty relation and will not fire any query to the database. - -* Added `create_join_table` migration helper to create HABTM join tables. - - ```ruby - create_join_table :products, :categories - # => - # create_table :categories_products, :id => false do |td| - # td.integer :product_id, :null => false - # td.integer :category_id, :null => false - # end - ``` - -* The primary key is always initialized in the `@attributes` hash to nil (unless another value has been specified). - -* In previous releases, the following would generate a single query with an OUTER JOIN comments, rather than two separate queries: - - ```ruby - Post.includes(:comments).where("comments.name = 'foo'") - ``` - - This behaviour relies on matching SQL string, which is an inherently flawed idea unless we write an SQL parser, which we do not wish to do. Therefore, it is now deprecated. - - To avoid deprecation warnings and for future compatibility, you must explicitly state which tables you reference, when using SQL snippets: - - ```ruby - Post.includes(:comments).where("comments.name = 'foo'").references(:comments) - ``` - - Note that you do not need to explicitly specify references in the following cases, as they can be automatically inferred: - - ```ruby - Post.where(comments: { name: 'foo' }) - Post.where('comments.name' => 'foo') - Post.order('comments.name') - ``` - - You also do not need to worry about this unless you are doing eager loading. Basically, don't worry unless you see a deprecation warning or (in future releases) an SQL error due to a missing JOIN. - -* Support for the `schema_info` table has been dropped. Please switch to `schema_migrations`. - -* Connections *must* be closed at the end of a thread. If not, your connection pool can fill and an exception will be raised. - -* Added the `ActiveRecord::Model` module which can be included in a class as an alternative to inheriting from `ActiveRecord::Base`: - - ```ruby - class Post - include ActiveRecord::Model - end - ``` - -* PostgreSQL hstore records can be created. - -* PostgreSQL hstore types are automatically deserialized from the database. - -* Added `#update_columns` method which updates the attributes from the passed-in hash without calling save, hence skipping validations and callbacks. `ActiveRecordError` will be raised when called on new objects or when at least one of the attributes is marked as read only. - - ```ruby - post.attributes # => {"id"=>2, "title"=>"My title", "body"=>"My content", "author"=>"Peter"} - post.update_columns({title: 'New title', author: 'Sebastian'}) # => true - post.attributes # => {"id"=>2, "title"=>"New title", "body"=>"My content", "author"=>"Sebastian"} - ``` +### Notable changes ### Deprecations -* Deprecated most of the 'dynamic finder' methods. All dynamic methods except for `find_by_...` and `find_by_...!` are deprecated. Here's how you can rewrite the code: - - ```ruby - find_all_by_... can be rewritten using where(...) - find_last_by_... can be rewritten using where(...).last - scoped_by_... can be rewritten using where(...) - find_or_initialize_by_... can be rewritten using where(...).first_or_initialize - find_or_create_by_... can be rewritten using where(...).first_or_create - find_or_create_by_...! can be rewritten using where(...).first_or_create! - ``` - - The implementation of the deprecated dynamic finders has been moved to the `active_record_deprecated_finders` gem. - -* Deprecated the old-style hash based finder API. This means that methods which previously accepted "finder options" no longer do. For example this: - - ```ruby - Post.find(:all, :conditions => { :comments_count => 10 }, :limit => 5) - ``` - - should be rewritten in the new style which has existed since Rails 3: - - ```ruby - Post.where(comments_count: 10).limit(5) - ``` - - Note that as an interim step, it is possible to rewrite the above as: - - ```ruby - Post.scoped(:where => { :comments_count => 10 }, :limit => 5) - ``` - - This could save you a lot of work if there is a lot of old-style finder usage in your application. - - Calling `Post.scoped(options)` is a shortcut for `Post.scoped.merge(options)`. `Relation#merge` now accepts a hash of options, but they must be identical to the names of the equivalent finder method. These are mostly identical to the old-style finder option names, except in the following cases: - - ``` - :conditions becomes :where - :include becomes :includes - :extend becomes :extending - ``` - - The code to implement the deprecated features has been moved out to the `active_record_deprecated_finders` gem. This gem is a dependency of Active Record in Rails 4.0. It will no longer be a dependency from Rails 4.1, but if your app relies on the deprecated features then you can add it to your own Gemfile. It will be maintained by the Rails core team until Rails 5.0 is released. - -* Deprecate eager-evaluated scopes. - - Don't use this: - - ```ruby - scope :red, where(color: 'red') - default_scope where(color: 'red') - ``` - - Use this: - - ```ruby - scope :red, -> { where(color: 'red') } - default_scope { where(color: 'red') } - ``` - - The former has numerous issues. It is a common newbie gotcha to do the following: - - ```ruby - scope :recent, where(published_at: Time.now - 2.weeks) - ``` - - Or a more subtle variant: - - ```ruby - scope :recent, -> { where(published_at: Time.now - 2.weeks) } - scope :recent_red, recent.where(color: 'red') - ``` - - Eager scopes are also very complex to implement within Active Record, and there are still bugs. For example, the following does not do what you expect: - - ```ruby - scope :remove_conditions, except(:where) - where(...).remove_conditions # => still has conditions - ``` - -* Added deprecation for the `:dependent => :restrict` association option. - -* Up until now `has_many` and `has_one, :dependent => :restrict` option raised a `DeleteRestrictionError` at the time of destroying the object. Instead, it will add an error on the model. - -* To fix this warning, make sure your code isn't relying on a `DeleteRestrictionError` and then add `config.active_record.dependent_restrict_raises = false` to your application config. - -* New rails application would be generated with the `config.active_record.dependent_restrict_raises = false` in the application config. - -* The migration generator now creates a join table with (commented) indexes every time the migration name contains the word "join_table". - -* `ActiveRecord::SessionStore` is removed from Rails 4.0 and is now a separate [gem](https://github.com/rails/activerecord-session_store). - Active Model ------------ -* Changed `AM::Serializers::JSON.include_root_in_json` default value to false. Now, AM Serializers and AR objects have the same default behaviour. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activemodel/CHANGELOG.md) for detailed changes. - ```ruby - class User < ActiveRecord::Base; end +### Notable changes - class Person - include ActiveModel::Model - include ActiveModel::AttributeMethods - include ActiveModel::Serializers::JSON +* Add `ActiveModel::ForbiddenAttributesProtection`, a simple module to protect attributes from mass assignment when non-permitted attributes are passed. - attr_accessor :name, :age +* Added `ActiveModel::Model`, a mixin to make Ruby objects work with Action Pack out of box. - def attributes - instance_values - end - end +### Deprecations - user.as_json - => {"id"=>1, "name"=>"Konata Izumi", "age"=>16, "awesome"=>true} - # root is not included +Active Support +-------------- - person.as_json - => {"name"=>"Francesco", "age"=>22} - # root is not included - ``` +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activesupport/CHANGELOG.md) for detailed changes. -* Passing false hash values to `validates` will no longer enable the corresponding validators. +### Notable changes -* `ConfirmationValidator` error messages will attach to `:#{attribute}_confirmation` instead of `attribute`. +* Replace deprecated `memcache-client` gem with `dalli` in ActiveSupport::Cache::MemCacheStore. -* Added `ActiveModel::Model`, a mixin to make Ruby objects work with Action Pack out of the box. +* Optimize ActiveSupport::Cache::Entry to reduce memory and processing overhead. -* `ActiveModel::Errors#to_json` supports a new parameter `:full_messages`. +* Inflections can now be defined per locale. `singularize` and `pluralize` accept locale as an extra argument. -* Trims down the API by removing `valid?` and `errors.full_messages`. +* `Object#try` will now return nil instead of raise a NoMethodError if the receiving object does not implement the method, but you can still get the old behavior by using the new `Object#try!`. -### Deprecations +* `String#to_date` now raises `Argument Error: invalid date` instead of `NoMethodError: undefined method 'div' for nil:NilClass` + when given an invalid date. It is now the same as `Date.parse`, and it accepts more invalid dates than 3.x, such as: -Active Resource ---------------- + ``` + # ActiveSupport 3.x + "asdf".to_date # => NoMethodError: undefined method `div' for nil:NilClass + "333".to_date # => NoMethodError: undefined method `div' for nil:NilClass -* Active Resource is removed from Rails 4.0 and is now a separate [gem](https://github.com/rails/activeresource). + # ActiveSupport 4 + "asdf".to_date # => ArgumentError: invalid date + "333".to_date # => Fri, 29 Nov 2013 + ``` -Active Support --------------- +### Deprecations -* Add default values to all `ActiveSupport::NumberHelper` methods, to avoid errors with empty locales or missing values. +* Deprecate `ActiveSupport::TestCase#pending` method, use `skip` from MiniTest instead. -* `Time#change` now works with time values with offsets other than UTC or the local time zone. +* `ActiveSupport::Benchmarkable#silence` has been deprecated due to its lack of thread safety. It will be removed without replacement in Rails 4.1. -* Add `Time#prev_quarter` and `Time#next_quarter` short-hands for `months_ago(3)` and `months_since(3)`. +* `ActiveSupport::JSON::Variable` is deprecated. Define your own `#as_json` and `#encode_json` methods for custom JSON string literals. -* Remove obsolete and unused `require_association` method from dependencies. +* Deprecates the compatibility method `Module#local_constant_names`, use `Module#local_constants` instead (which returns symbols). -* Add `:instance_accessor` option for `config_accessor`. +* `BufferedLogger` is deprecated. Use `ActiveSupport::Logger`, or the logger from Ruby standard library. - ```ruby - class User - include ActiveSupport::Configurable - config_accessor :allowed_access, instance_accessor: false - end +* Deprecate `assert_present` and `assert_blank` in favor of `assert object.blank?` and `assert object.present?` - User.new.allowed_access = true # => NoMethodError - User.new.allowed_access # => NoMethodError - ``` +Action Pack +----------- -* `ActionView::Helpers::NumberHelper` methods have been moved to `ActiveSupport::NumberHelper` and are now available via `Numeric#to_s`. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionpack/CHANGELOG.md) for detailed changes. -* `Numeric#to_s` now accepts the formatting options :phone, :currency, :percentage, :delimited, :rounded, :human, and :human_size. +### Notable changes -* Add `Hash#transform_keys`, `Hash#transform_keys!`, `Hash#deep_transform_keys` and `Hash#deep_transform_keys!`. +* Change the stylesheet of exception pages for development mode. Additionally display also the line of code and fragment that raised the exception in all exceptions pages. -* Changed xml type datetime to dateTime (with upper case letter T). +### Deprecations -* Add `:instance_accessor` option for `class_attribute`. -* `constantize` now looks in the ancestor chain. +Active Record +------------- -* Add `Hash#deep_stringify_keys` and `Hash#deep_stringify_keys!` to convert all keys from a `Hash` instance into strings. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activerecord/CHANGELOG.md) for detailed changes. -* Add `Hash#deep_symbolize_keys` and `Hash#deep_symbolize_keys!` to convert all keys from a `Hash` instance into symbols. +### Notable changes -* `Object#try` can't call private methods. +* Improve ways to write `change` migrations, making the old `up` & `down` methods no longer necessary. -* AS::Callbacks#run_callbacks remove key argument. + * The methods `drop_table` and `remove_column` are now reversible, as long as the necessary information is given. + The method `remove_column` used to accept multiple column names; instead use `remove_columns` (which is not revertible). + The method `change_table` is also reversible, as long as its block doesn't call `remove`, `change` or `change_default` -* `deep_dup` works more expectedly now and duplicates also values in `Hash` instances and elements in `Array` instances. + * New method `reversible` makes it possible to specify code to be run when migrating up or down. + See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/migrations.md#using-the-reversible-method) -* Inflector no longer applies ice -> ouse to words like slice, police. + * New method `revert` will revert a whole migration or the given block. + If migrating down, the given migration / block is run normally. + See the [Guide on Migration](https://github.com/rails/rails/blob/master/guides/source/migrations.md#reverting-previous-migrations) -* Add `ActiveSupport::Deprecations.behavior = :silence` to completely ignore Rails runtime deprecations. +* Adds PostgreSQL array type support. Any datatype can be used to create an array column, with full migration and schema dumper support. -* Make `Module#delegate` stop using send - can no longer delegate to private methods. +* Add `Relation#load` to explicitly load the record and return `self`. -* AS::Callbacks deprecate :rescuable option. +* `Model.all` now returns an `ActiveRecord::Relation`, rather than an array of records. Use `Relation#to_a` if you really want an array. In some specific cases, this may cause breakage when upgrading. -* Adds `Integer#ordinal` to get the ordinal suffix string of an integer. +* Added `ActiveRecord::Migration.check_pending!` that raises an error if migrations are pending. -* AS::Callbacks :per_key option is no longer supported. +* Added custom coders support for `ActiveRecord::Store`. Now you can set your custom coder like this: -* AS::Callbacks#define_callbacks add :skip_after_callbacks_if_terminated option. + store :settings, accessors: [ :color, :homepage ], coder: JSON -* Add html_escape_once to ERB::Util, and delegate escape_once tag helper to it. +* `mysql` and `mysql2` connections will set `SQL_MODE=STRICT_ALL_TABLES` by default to avoid silent data loss. This can be disabled by specifying `strict: false` in your `database.yml`. -* Remove `ActiveSupport::TestCase#pending` method, use `skip` instead. +* Remove IdentityMap. -* Deletes the compatibility method `Module#method_names`, use `Module#methods` from now on (which returns symbols). +* Remove automatic execution of EXPLAIN queries. The option `active_record.auto_explain_threshold_in_seconds` is no longer used and should be removed. -* Deletes the compatibility method `Module#instance_method_names`, use `Module#instance_methods` from now on (which returns symbols). +* Adds `ActiveRecord::NullRelation` and `ActiveRecord::Relation#none` implementing the null object pattern for the Relation class. -* Unicode database updated to 6.1.0. +* Added `create_join_table` migration helper to create HABTM join tables. -* Adds `encode_big_decimal_as_string` option to force JSON serialization of BigDecimals as numeric instead of wrapping them in strings for safety. +* Allows PostgreSQL hstore records to be created. ### Deprecations -* `ActiveSupport::Callbacks`: deprecate usage of filter object with `#before` and `#after` methods as `around` callback. +* Deprecated the old-style hash based finder API. This means that methods which previously accepted "finder options" no longer do. -* `BufferedLogger` is deprecated. Use `ActiveSupport::Logger` or the `logger` from Ruby stdlib. +* All dynamic methods except for `find_by_...` and `find_by_...!` are deprecated. Here's + how you can rewrite the code: -* Deprecates the compatibility method `Module#local_constant_names` and use `Module#local_constants` instead (which returns symbols). + * `find_all_by_...` can be rewritten using `where(...)`. + * `find_last_by_...` can be rewritten using `where(...).last`. + * `scoped_by_...` can be rewritten using `where(...)`. + * `find_or_initialize_by_...` can be rewritten using `find_or_initialize_by(...)`. + * `find_or_create_by_...` can be rewritten using `find_or_create_by(...)`. + * `find_or_create_by_...!` can be rewritten using `find_or_create_by!(...)`. Credits ------- |