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diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md new file mode 100644 index 0000000000..a39dd9ace0 --- /dev/null +++ b/guides/source/4_2_release_notes.md @@ -0,0 +1,396 @@ +Ruby on Rails 4.2 Release Notes +=============================== + +Highlights in Rails 4.2: + +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 4.2 +---------------------- + +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 4.1 in case you +haven't and make sure your application still runs as expected before attempting +an update to Rails 4.2. A list of things to watch out for when upgrading is +available in the +[Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#upgrading-from-rails-4-1-to-rails-4-2) +guide. + + +Major Features +-------------- + +### Foreign key support + +The migration DSL now supports adding and removing foreign keys. They are dumped +to `schema.rb` as well. At this time, only the `mysql`, `mysql2` and `postgresql` +adapters support foreign keys. + +```ruby +# add a foreign key to `articles.author_id` referencing `authors.id` +add_foreign_key :articles, :authors + +# add a foreign key to `articles.author_id` referencing `users.lng_id` +add_foreign_key :articles, :users, column: :author_id, primary_key: "lng_id" + +# remove the foreign key on `accounts.branch_id` +remove_foreign_key :accounts, :branches + +# remove the foreign key on `accounts.owner_id` +remove_foreign_key :accounts, column: :owner_id +``` + +See the API documentation on +[add_foreign_key](http://api.rubyonrails.org/v4.2.0/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_foreign_key) +and +[remove_foreign_key](http://api.rubyonrails.org/v4.2.0/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-remove_foreign_key) +for a full description. + + +Railties +-------- + +Please refer to the [Changelog][railties] for detailed changes. + +### Removals + +* The `rails application` command has been removed without replacement. + ([Pull Request](https://github.com/rails/rails/pull/11616)) + +### Deprecations + +* Deprecated `Rails::Rack::LogTailer` without replacement. + ([Commit](https://github.com/rails/rails/commit/84a13e019e93efaa8994b3f8303d635a7702dbce)) + +### Notable changes + +* Introduced `--skip-gems` option in the app generator to skip gems such as + `turbolinks` and `coffee-rails` that does not have their own specific flags. + ([Commit](https://github.com/rails/rails/commit/10565895805887d4faf004a6f71219da177f78b7)) + +* Introduced `bin/setup` script to bootstrap an application. + ([Pull Request](https://github.com/rails/rails/pull/15189)) + +* Changed default value for `config.assets.digest` to `true` in development. + ([Pull Request](https://github.com/rails/rails/pull/15155)) + +* Introduced an API to register new extensions for `rake notes`. + ([Pull Request](https://github.com/rails/rails/pull/14379)) + +* Introduced `Rails.gem_version` as a convenience method to return `Gem::Version.new(Rails.version)`. + ([Pull Request](https://github.com/rails/rails/pull/14101)) + +* Introduced an `after_bundle` callback in the Rails templates. + ([Pull Request](https://github.com/rails/rails/pull/16359)) + + +Action Pack +----------- + +Please refer to the [Changelog][action-pack] for detailed changes. + +### Deprecations + +* Deprecated support for setting the `:to` option of a router to a symbol or a + string that does not contain a `#` character: + + ```ruby + get '/posts', to: MyRackApp => (No change necessary) + get '/posts', to: 'post#index' => (No change necessary) + get '/posts', to: 'posts' => get '/posts', controller: :posts + get '/posts', to: :index => get '/posts', action: :index + ``` + + ([Commit](https://github.com/rails/rails/commit/cc26b6b7bccf0eea2e2c1a9ebdcc9d30ca7390d9)) + +### Notable changes + +* `render nothing: true` or rendering a `nil` body no longer add a single + space padding to the response body. + ([Pull Request](https://github.com/rails/rails/pull/14883)) + +* Introduced the `always_permitted_parameters` option to configure which + parameters are permitted globally. The default value of this configuration + is `['controller', 'action']`. + ([Pull Request](https://github.com/rails/rails/pull/15933)) + +* The `*_filter` family methods has been removed from the documentation. Their + usage are discouraged in favor of the `*_action` family methods: + + ``` + after_filter => after_action + append_after_filter => append_after_action + append_around_filter => append_around_action + append_before_filter => append_before_action + around_filter => around_action + before_filter => before_action + prepend_after_filter => prepend_after_action + prepend_around_filter => prepend_around_action + prepend_before_filter => prepend_before_action + skip_after_filter => skip_after_action + skip_around_filter => skip_around_action + skip_before_filter => skip_before_action + skip_filter => skip_action_callback + ``` + + If your application is depending on these methods, you should use the + replacement `*_action` methods instead. These methods will be deprecated in + the future and eventually removed from Rails. + + (Commit [1](https://github.com/rails/rails/commit/6c5f43bab8206747a8591435b2aa0ff7051ad3de), + [2](https://github.com/rails/rails/commit/489a8f2a44dc9cea09154ee1ee2557d1f037c7d4)) + +* Added HTTP method `MKCALENDAR` from RFC-4791 + ([Pull Request](https://github.com/rails/rails/pull/15121)) + +* `*_fragment.action_controller` notifications now include the controller and action name + in the payload. + ([Pull Request](https://github.com/rails/rails/pull/14137)) + +* Segments that are passed into URL helpers are now automatically escaped. + ([Commit](https://github.com/rails/rails/commit/5460591f0226a9d248b7b4f89186bd5553e7768f)) + +* Improved Routing Error page with fuzzy matching for route search. + ([Pull Request](https://github.com/rails/rails/pull/14619)) + +* Added option to disable logging of CSRF failures. + ([Pull Request](https://github.com/rails/rails/pull/14280)) + + +Action View +------------- + +Please refer to the [Changelog][action-view] for detailed changes. + +### Deprecations + +* Deprecated `AbstractController::Base.parent_prefixes`. + Override `AbstractController::Base.local_prefixes` when you want to change + where to find views. + ([Pull Request](https://github.com/rails/rails/pull/15026)) + +* Deprecated `ActionView::Digestor#digest(name, format, finder, options = {})`, + arguments should be passed as a hash instead. + ([Pull Request](https://github.com/rails/rails/pull/14243)) + +### Notable changes + +* The form helpers no longer generate a `<div>` element with inline CSS around + the hidden fields. + ([Pull Request](https://github.com/rails/rails/pull/14738)) + + +Action Mailer +------------- + +Please refer to the [Changelog][action-mailer] for detailed changes. + +### Notable changes + +* Added the `show_previews` configuration option for enabling mailer previews + outside of the development environment. + ([Pull Request](https://github.com/rails/rails/pull/15970)) + + +Active Record +------------- + +Please refer to the +[Changelog](https://github.com/rails/rails/blob/4-2-stable/activerecord/CHANGELOG.md) +for detailed changes. + +### Removals + +* Removed `cache_attributes` and friends. All attributes are cached. + ([Pull Request](https://github.com/rails/rails/pull/15429)) + +* Removed deprecated method `ActiveRecord::Base.quoted_locking_column`. + ([Pull Request](https://github.com/rails/rails/pull/15612)) + +* Removed deprecated `ActiveRecord::Migrator.proper_table_name`. Use the + `proper_table_name` instance method on `ActiveRecord::Migration` instead. + ([Pull Request](https://github.com/rails/rails/pull/15512)) + +* Removed unused `:timestamp` type. Transparently alias it to `:datetime` + in all cases. Fixes inconsistencies when column types are sent outside of + `ActiveRecord`, such as for XML Serialization. + ([Pull Request](https://github.com/rails/rails/pull/15184)) + +### Deprecations + +* Deprecated broken support for automatic detection of counter caches on + `has_many :through` associations. You should instead manually specify the + counter cache on the `has_many` and `belongs_to` associations for the + through records. + ([Pull Request](https://github.com/rails/rails/pull/15754)) + +* Deprecated `serialized_attributes` without replacement. + ([Pull Request](https://github.com/rails/rails/pull/15704)) + +* Deprecated returning `nil` from `column_for_attribute` when no column + exists. It will return a null object in Rails 5.0 + ([Pull Request](https://github.com/rails/rails/pull/15878)) + +* Deprecated using `.joins`, `.preload` and `.eager_load` with associations + that depends on the instance state (i.e. those defined with a scope that + takes an argument) without replacement. + ([Commit](https://github.com/rails/rails/commit/ed56e596a0467390011bc9d56d462539776adac1)) + +* Deprecated passing Active Record objects to `.find` or `.exists?`. Call + `#id` on the objects first. + (Commit [1](https://github.com/rails/rails/commit/d92ae6ccca3bcfd73546d612efaea011270bd270), + [2](https://github.com/rails/rails/commit/d35f0033c7dec2b8d8b52058fb8db495d49596f7)) + +* Deprecated half-baked support for PostgreSQL range values with excluding + beginnings. We currently map PostgreSQL ranges to Ruby ranges. This conversion + is not fully possible because the Ruby range does not support excluded + beginnings. + + The current solution of incrementing the beginning is not correct + and is now deprecated. For subtypes where we don't know how to increment + (e.g. `#succ` is not defined) it will raise an `ArgumentError` for ranges + with excluding beginnings. + + ([Commit](https://github.com/rails/rails/commit/91949e48cf41af9f3e4ffba3e5eecf9b0a08bfc3)) + +### Notable changes + +* Added a `:required` option to singular associations, which defines a + presence validation on the association. + ([Pull Request](https://github.com/rails/rails/pull/16056)) + +* Introduced `ActiveRecord::Base#validate!` that raises `RecordInvalid` if the + record is invalid. + ([Pull Request](https://github.com/rails/rails/pull/8639)) + +* `ActiveRecord::Base#reload` now behaves the same as `m = Model.find(m.id)`, + meaning that it no longer retains the extra attributes from custom + `select`s. + ([Pull Request](https://github.com/rails/rails/pull/15866)) + +* Introduced the `bin/rake db:purge` task to empty the database for the + current environment. + ([Commit](https://github.com/rails/rails/commit/e2f232aba15937a4b9d14bd91e0392c6d55be58d)) + +* `ActiveRecord::Dirty` now detects in-place changes to mutable values. + Serialized attributes on ActiveRecord models will no longer save when + unchanged. This also works with other types such as string columns and json + columns on PostgreSQL. + (Pull Requests [1](https://github.com/rails/rails/pull/15674), + [2](https://github.com/rails/rails/pull/15786), + [3](https://github.com/rails/rails/pull/15788)) + +* Added support for `#pretty_print` in `ActiveRecord::Base` objects. + ([Pull Request](https://github.com/rails/rails/pull/15172)) + +* PostgreSQL and SQLite adapters no longer add a default limit of 255 + characters on string columns. + ([Pull Request](https://github.com/rails/rails/pull/14579)) + +* `sqlite3:///some/path` now resolves to the absolute system path + `/some/path`. For relative paths, use `sqlite3:some/path` instead. + (Previously, `sqlite3:///some/path` resolved to the relative path + `some/path`. This behaviour was deprecated on Rails 4.1.) + ([Pull Request](https://github.com/rails/rails/pull/14569)) + +* Introduced `#validate` as an alias for `#valid?`. + ([Pull Request](https://github.com/rails/rails/pull/14456)) + +* `#touch` now accepts multiple attributes to be touched at once. + ([Pull Request](https://github.com/rails/rails/pull/14423)) + +* Added support for fractional seconds for MySQL 5.6 and above. + (Pull Request [1](https://github.com/rails/rails/pull/8240), + [2](https://github.com/rails/rails/pull/14359)) + +* Added support for the `citext` column type in PostgreSQL adapter. + ([Pull Request](https://github.com/rails/rails/pull/12523)) + +* Added support for user-created range types in PostgreSQL adapter. + ([Commit](https://github.com/rails/rails/commit/4cb47167e747e8f9dc12b0ddaf82bdb68c03e032)) + + +Active Model +------------ + +Please refer to the [Changelog][active-model] for detailed changes. + +### Removals + +* Removed deprecated `Validator#setup` without replacement. + ([Pull Request](https://github.com/rails/rails/pull/15617)) + +### Notable changes + +* Introduced `undo_changes` method in `ActiveModel::Dirty` to restore the + changed (dirty) attributes to their previous values. + ([Pull Request](https://github.com/rails/rails/pull/14861)) + +* `has_secure_password` now verifies that the given password is less than 72 + characters if validations are enabled. + ([Pull Request](https://github.com/rails/rails/pull/15708)) + +* Introduced `#validate` as an alias for `#valid?`. + ([Pull Request](https://github.com/rails/rails/pull/14456)) + + +Active Support +-------------- + +Please refer to the [Changelog][active-support] for detailed changes. + +### Removals + +* Removed deprecated `Numeric#ago`, `Numeric#until`, `Numeric#since`, + `Numeric#from_now`. + ([Commit](https://github.com/rails/rails/commit/f1eddea1e3f6faf93581c43651348f48b2b7d8bb)) + +* Removed deprecated string based terminators for `ActiveSupport::Callbacks`. + ([Pull Request](https://github.com/rails/rails/pull/15100)) + +### Deprecations + +* Deprecated `Class#superclass_delegating_accessor`, use + `Class#class_attribute` instead. + ([Pull Request](https://github.com/rails/rails/pull/14271)) + +* Deprecated `ActiveSupport::SafeBuffer#prepend!` as + `ActiveSupport::SafeBuffer#prepend` now performs the same function. + ([Pull Request](https://github.com/rails/rails/pull/14529)) + +### Notable changes + +* Added `Hash#transform_values` and `Hash#transform_values!` to simplify a + common pattern where the values of a hash must change, but the keys are left + the same. + ([Pull Request](https://github.com/rails/rails/pull/15819)) + +* The `humanize` inflector helper now strips any leading underscores. + ([Commit](https://github.com/rails/rails/commit/daaa21bc7d20f2e4ff451637423a25ff2d5e75c7)) + +* Introduce `Concern#class_methods` as an alternative to + `module ClassMethods`, as well as `Kernel#concern` to avoid the + `module Foo; extend ActiveSupport::Concern; end` boilerplate. + ([Commit](https://github.com/rails/rails/commit/b16c36e688970df2f96f793a759365b248b582ad)) + + +Credits +------- + +See the +[full list of contributors to Rails](http://contributors.rubyonrails.org/) for +the many people who spent many hours making Rails the stable and robust +framework it is today. Kudos to all of them. + +[railties]: https://github.com/rails/rails/blob/4-2-stable/railties/CHANGELOG.md +[action-pack]: https://github.com/rails/rails/blob/4-2-stable/actionpack/CHANGELOG.md +[action-view]: https://github.com/rails/rails/blob/4-2-stable/actionview/CHANGELOG.md +[action-mailer]: https://github.com/rails/rails/blob/4-2-stable/actionmailer/CHANGELOG.md +[active-record]: https://github.com/rails/rails/blob/4-2-stable/activerecord/CHANGELOG.md +[active-model]: https://github.com/rails/rails/blob/4-2-stable/activemodel/CHANGELOG.md +[active-support]: https://github.com/rails/rails/blob/4-2-stable/activesupport/CHANGELOG.md |