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Diffstat (limited to 'guides/source/4_0_release_notes.md')
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1 files changed, 67 insertions, 17 deletions
diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md index 66e26c63cb..19c690233c 100644 --- a/guides/source/4_0_release_notes.md +++ b/guides/source/4_0_release_notes.md @@ -15,7 +15,7 @@ These release notes cover only the major changes. To know about various bug fixe Upgrading to Rails 4.0 ---------------------- -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. 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-3-2-to-rails-4-0) guide. Creating a Rails 4.0 application @@ -50,10 +50,47 @@ $ ruby /path/to/rails/railties/bin/rails new myapp --dev Major Features -------------- -TODO. Give a list and then talk about each of them briefly. We can point to relevant code commits or documentation from these sections. - [](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 --------------------------- @@ -79,7 +116,7 @@ Documentation Railties -------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railties/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/railties/CHANGELOG.md) for detailed changes. ### Notable changes @@ -102,7 +139,7 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/railt Action Mailer ------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actionmailer/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionmailer/CHANGELOG.md) for detailed changes. ### Notable changes @@ -111,7 +148,7 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actio Active Model ------------ -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activemodel/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activemodel/CHANGELOG.md) for detailed changes. ### Notable changes @@ -124,36 +161,49 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activ Active Support -------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activesupport/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activesupport/CHANGELOG.md) for detailed changes. ### Notable changes -* Replace deprecated `memcache-client` gem with `dalli` in ActiveSupport::Cache::MemCacheStore. +* Replace deprecated `memcache-client` gem with `dalli` in `ActiveSupport::Cache::MemCacheStore`. -* Optimize ActiveSupport::Cache::Entry to reduce memory and processing overhead. +* Optimize `ActiveSupport::Cache::Entry` to reduce memory and processing overhead. * Inflections can now be defined per locale. `singularize` and `pluralize` accept locale as an extra argument. * `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!`. +* `String#to_date` now raises `ArgumentError: 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: + + ``` + # ActiveSupport 3.x + "asdf".to_date # => NoMethodError: undefined method `div' for nil:NilClass + "333".to_date # => NoMethodError: undefined method `div' for nil:NilClass + + # ActiveSupport 4 + "asdf".to_date # => ArgumentError: invalid date + "333".to_date # => Fri, 29 Nov 2013 + ``` + ### Deprecations * Deprecate `ActiveSupport::TestCase#pending` method, use `skip` from MiniTest instead. -* ActiveSupport::Benchmarkable#silence has been deprecated due to its lack of thread safety. It will be removed without replacement in Rails 4.1. +* `ActiveSupport::Benchmarkable#silence` has been deprecated due to its lack of thread safety. It will be removed without replacement in Rails 4.1. * `ActiveSupport::JSON::Variable` is deprecated. Define your own `#as_json` and `#encode_json` methods for custom JSON string literals. -* Deprecates the compatibility method Module#local_constant_names, use Module#local_constants instead (which returns symbols). +* Deprecates the compatibility method `Module#local_constant_names`, use `Module#local_constants` instead (which returns symbols). -* BufferedLogger is deprecated. Use ActiveSupport::Logger, or the logger from Ruby standard library. +* `BufferedLogger` is deprecated. Use `ActiveSupport::Logger`, or the logger from Ruby standard library. * Deprecate `assert_present` and `assert_blank` in favor of `assert object.blank?` and `assert object.present?` Action Pack ----------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actionpack/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/actionpack/CHANGELOG.md) for detailed changes. ### Notable changes @@ -165,7 +215,7 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/actio Active Record ------------- -Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activerecord/CHANGELOG.md) for detailed changes. +Please refer to the [Changelog](https://github.com/rails/rails/blob/4-0-stable/activerecord/CHANGELOG.md) for detailed changes. ### Notable changes @@ -216,9 +266,9 @@ Please refer to the [Changelog](https://github.com/rails/rails/blob/master/activ * `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 `find_or_create_by(...)` or `where(...).first_or_create`. - * `find_or_create_by_...!` can be rewritten using `find_or_create_by!(...)` or `where(...).first_or_create!`. + * `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 ------- |