Ruby on Rails 4.1 Release Notes
===============================
Highlights in Rails 4.1:
* Spring application preloader
* `config/secrets.yml`
* Action Pack variants
* Action Mailer previews
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 4.1
----------------------
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 4.0 in case you
haven't and make sure your application still runs as expected before attempting
an update to Rails 4.1. 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-4-0-to-rails-4-1)
guide.
Major Features
--------------
### Spring Application Preloader
Spring is a Rails application preloader. It speeds up development by keeping
your application running in the background so you don't need to boot it every
time you run a test, rake task or migration.
New Rails 4.1 applications will ship with "springified" binstubs. This means
that `bin/rails` and `bin/rake` will automatically take advantage of preloaded
spring environments.
**Running rake tasks:**
```
bin/rake test:models
```
**Running a Rails command:**
```
bin/rails console
```
**Spring introspection:**
```
$ bin/spring status
Spring is running:
1182 spring server | my_app | started 29 mins ago
3656 spring app | my_app | started 23 secs ago | test mode
3746 spring app | my_app | started 10 secs ago | development mode
```
Have a look at the
[Spring README](https://github.com/rails/spring/blob/master/README.md) to
see all available features.
See the [Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#spring)
guide on how to migrate existing applications to use this feature.
### `config/secrets.yml`
Rails 4.1 generates a new `secrets.yml` file in the `config` folder. By default,
this file contains the application's `secret_key_base`, but it could also be
used to store other secrets such as access keys for external APIs.
The secrets added to this file are accessible via `Rails.application.secrets`.
For example, with the following `config/secrets.yml`:
```yaml
development:
secret_key_base: 3b7cd727ee24e8444053437c36cc66c3
some_api_key: SOMEKEY
```
`Rails.application.secrets.some_api_key` returns `SOMEKEY` in the development
environment.
See the [Upgrading Ruby on Rails](upgrading_ruby_on_rails.html#config-secrets-yml)
guide on how to migrate existing applications to use this feature.
### Action Pack Variants
We often want to render different HTML/JSON/XML templates for phones,
tablets, and desktop browsers. Variants make it easy.
The request variant is a specialization of the request format, like `:tablet`,
`:phone`, or `:desktop`.
You can set the variant in a `before_action`:
```ruby
request.variant = :tablet if request.user_agent =~ /iPad/
```
Respond to variants in the action just like you respond to formats:
```ruby
respond_to do |format|
format.html do |html|
html.tablet # renders app/views/projects/show.html+tablet.erb
html.phone { extra_setup; render ... }
end
end
```
Provide separate templates for each format and variant:
```
app/views/projects/show.html.erb
app/views/projects/show.html+tablet.erb
app/views/projects/show.html+phone.erb
```
You can also simplify the variants definition using the inline syntax:
```ruby
respond_to do |format|
format.js { render "trash" }
format.html.phone { redirect_to progress_path }
format.html.none { render "trash" }
end
```
### Action Mailer Previews
Action Mailer previews provide a way to visually see how emails look by visiting
a special URL that renders them.
You implement a preview class whose methods return the mail object you'd like
to check:
```ruby
class NotifierPreview < ActionMailer::Preview
def welcome
Notifier.welcome(User.first)
end
end
```
The preview is available in http://localhost:3000/rails/mailers/notifier/welcome,
and a list of them in http://localhost:3000/rails/mailers.
By default, these preview classes live in `test/mailers/previews`.
This can be configured using the `preview_path` option.
See its
[documentation](http://api.rubyonrails.org/v4.1.0/classes/ActionMailer/Base.html)
for a detailed write up.
### Active Record enums
Declare an enum attribute where the values map to integers in the database, but
can be queried by name.
```ruby
class Conversation < ActiveRecord::Base
enum status: [ :active, :archived ]
end
conversation.archived!
conversation.active? # => false
conversation.status # => "archived"
Conversation.archived # => Relation for all archived Conversations
```
See its
[documentation](http://api.rubyonrails.org/v4.1.0/classes/ActiveRecord/Enum.html)
for a detailed write up.
### Message Verifiers
Message verifiers can be used to generate and verify signed messages. This can
be useful to safely transport sensitive data like remember-me tokens and
friends.
The method `Rails.application.message_verifier` returns a new message verifier
that signs messages with a key derived from secret_key_base and the given
message verifier name:
```ruby
signed_token = Rails.application.message_verifier(:remember_me).generate(token)
Rails.application.message_verifier(:remember_me).verify(signed_token) # => token
Rails.application.message_verifier(:remember_me).verify(tampered_token)
# raises ActiveSupport::MessageVerifier::InvalidSignature
```
### Module#concerning
A natural, low-ceremony way to separate responsibilities within a class:
```ruby
class Todo < ActiveRecord::Base
concerning :EventTracking do
included do
has_many :events
end
def latest_event
...
end
private
def some_internal_method
...
end
end
end
```
This example is equivalent to defining a `EventTracking` module inline,
extending it with `ActiveSupport::Concern`, then mixing it in to the
`Todo` class.
See its
[documentation](http://api.rubyonrails.org/v4.1.0/classes/Module/Concerning.html)
for a detailed write up and the intended use cases.
### CSRF protection from remote `<script>` tags
Cross-site request forgery (CSRF) protection now covers GET requests with
JavaScript responses, too. That prevents a third-party site from referencing
your JavaScript URL and attempting to run it to extract sensitive data.
This means any of your tests that hit `.js` URLs will now fail CSRF protection
unless they use `xhr`. Upgrade your tests to be explicit about expecting
XmlHttpRequests. Instead of `post :create, format: :js`, switch to the explicit
`xhr :post, :create, format: :js`.
Railties
--------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/railties/CHANGELOG.md)
for detailed changes.
### Removals
* Removed `update:application_controller` rake task.
* Removed deprecated `Rails.application.railties.engines`.
* Removed deprecated `threadsafe!` from Rails Config.
* Removed deprecated `ActiveRecord::Generators::ActiveModel#update_attributes` in
favor of `ActiveRecord::Generators::ActiveModel#update`.
* Removed deprecated `config.whiny_nils` option.
* Removed deprecated rake tasks for running tests: `rake test:uncommitted` and
`rake test:recent`.
### Notable changes
* The [Spring application
preloader](https://github.com/rails/spring) is now installed
by default for new applications. It uses the development group of
the Gemfile, so will not be installed in
production. ([Pull Request](https://github.com/rails/rails/pull/12958))
* `BACKTRACE` environment variable to show unfiltered backtraces for test
failures. ([Commit](https://github.com/rails/rails/commit/84eac5dab8b0fe9ee20b51250e52ad7bfea36553))
* Exposed `MiddlewareStack#unshift` to environment
configuration. ([Pull Request](https://github.com/rails/rails/pull/12479))
* Add `Application#message_verifier` method to return a message
verifier. ([Pull Request](https://github.com/rails/rails/pull/12995))
* The `test_help.rb` file which is required by the default generated test
helper will automatically keep your test database up-to-date with
`db/schema.rb` (or `db/structure.sql`). It raises an error if
reloading the schema does not resolve all pending migrations. Opt out
with `config.active_record.maintain_test_schema = false`. ([Pull
Request](https://github.com/rails/rails/pull/13528))
Action Pack
-----------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/actionpack/CHANGELOG.md)
for detailed changes.
### Removals
* Removed deprecated Rails application fallback for integration testing, set
`ActionDispatch.test_app` instead.
* Removed deprecated `page_cache_extension` config.
* Removed deprecated `ActionController::RecordIdentifier`, use
`ActionView::RecordIdentifier` instead.
* Removed deprecated constants from Action Controller:
| Removed | Successor |
|:-----------------------------------|:--------------------------------|
| ActionController::AbstractRequest | ActionDispatch::Request |
| ActionController::Request | ActionDispatch::Request |
| ActionController::AbstractResponse | ActionDispatch::Response |
| ActionController::Response | ActionDispatch::Response |
| ActionController::Routing | ActionDispatch::Routing |
| ActionController::Integration | ActionDispatch::Integration |
| ActionController::IntegrationTest | ActionDispatch::IntegrationTest |
### Notable changes
* `protect_from_forgery` also prevents cross-origin `<script>` tags.
Update your tests to use `xhr :get, :foo, format: :js` instead of
`get :foo, format: :js`.
([Pull Request](https://github.com/rails/rails/pull/13345))
* `#url_for` takes a hash with options inside an
array. ([Pull Request](https://github.com/rails/rails/pull/9599))
* Added `session#fetch` method fetch behaves similarly to
[Hash#fetch](http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch),
with the exception that the returned value is always saved into the
session. ([Pull Request](https://github.com/rails/rails/pull/12692))
* Separated Action View completely from Action
Pack. ([Pull Request](https://github.com/rails/rails/pull/11032))
Action Mailer
-------------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/actionmailer/CHANGELOG.md)
for detailed changes.
### Notable changes
* Instrument the generation of Action Mailer messages. The time it takes to
generate a message is written to the log. ([Pull Request](https://github.com/rails/rails/pull/12556))
Active Record
-------------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/activerecord/CHANGELOG.md)
for detailed changes.
### Removals
* Removed deprecated nil-passing to the following `SchemaCache` methods:
`primary_keys`, `tables`, `columns` and `columns_hash`.
* Removed deprecated block filter from `ActiveRecord::Migrator#migrate`.
* Removed deprecated String constructor from `ActiveRecord::Migrator`.
* Removed deprecated `scope` use without passing a callable object.
* Removed deprecated `transaction_joinable=` in favor of `begin_transaction`
with `d:joinable` option.
* Removed deprecated `decrement_open_transactions`.
* Removed deprecated `increment_open_transactions`.
* Removed deprecated `PostgreSQLAdapter#outside_transaction?`
method. You can use `#transaction_open?` instead.
* Removed deprecated `ActiveRecord::Fixtures.find_table_name` in favor of
`ActiveRecord::Fixtures.default_fixture_model_name`.
* Removed deprecated `columns_for_remove` from `SchemaStatements`.
* Removed deprecated `SchemaStatements#distinct`.
* Moved deprecated `ActiveRecord::TestCase` into the Rails test
suite. The class is no longer public and is only used for internal
Rails tests.
* Removed support for deprecated option `:restrict` for `:dependent`
in associations.
* Removed support for deprecated `:delete_sql`, `:insert_sql`, `:finder_sql`
and `:counter_sql` options in associations.
* Removed deprecated method `type_cast_code` from Column.
* Removed deprecated `ActiveRecord::Base#connection` method.
Make sure to access it via the class.
* Removed deprecation warning for `auto_explain_threshold_in_seconds`.
* Removed deprecated `:distinct` option from `Relation#count`.
* Removed deprecated methods `partial_updates`, `partial_updates?` and
`partial_updates=`.
* Removed deprecated method `scoped`.
* Removed deprecated method `default_scopes?`.
* Remove implicit join references that were deprecated in 4.0.
* Removed `activerecord-deprecated_finders` as a dependency.
Please see [upgrading
guide](upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to-rails-4-0-active-record)
for more info.
* Removed usage of `implicit_readonly`. Please use `readonly` method
explicitly to mark records as
`readonly`. ([Pull Request](https://github.com/rails/rails/pull/10769))
### Deprecations
* Deprecated `quoted_locking_column` method, which isn't used anywhere.
* Deprecated the delegation of Array bang methods for associations.
To use them, instead first call `#to_a` on the association to access the
array to be acted
on. ([Pull Request](https://github.com/rails/rails/pull/12129))
* Deprecated `ConnectionAdapters::SchemaStatements#distinct`,
as it is no longer used by internals. ([Pull Request](https://github.com/rails/rails/pull/10556))
* Deprecated `rake db:test:*` tasks as the test database is now
automatically maintained. See railties release notes. ([Pull
Request](https://github.com/rails/rails/pull/13528))
* Deprecate unused `ActiveRecord::Base.symbolized_base_class`
and `ActiveRecord::Base.symbolized_sti_name` without
replacement. [Commit](https://github.com/rails/rails/commit/97e7ca48c139ea5cce2fa9b4be631946252a1ebd)
### Notable changes
* Added `ActiveRecord::Base.to_param` for convenient "pretty" URLs derived from
a model's attribute or
method. ([Pull Request](https://github.com/rails/rails/pull/12891))
* Added `ActiveRecord::Base.no_touching`, which allows ignoring touch on
models. ([Pull Request](https://github.com/rails/rails/pull/12772))
* Unify boolean type casting for `MysqlAdapter` and `Mysql2Adapter`.
`type_cast` will return `1` for `true` and `0` for `false`. ([Pull Request](https://github.com/rails/rails/pull/12425))
* `.unscope` now removes conditions specified in
`default_scope`. ([Commit](https://github.com/rails/rails/commit/94924dc32baf78f13e289172534c2e71c9c8cade))
* Added `ActiveRecord::QueryMethods#rewhere` which will overwrite an existing,
named where condition. ([Commit](https://github.com/rails/rails/commit/f950b2699f97749ef706c6939a84dfc85f0b05f2))
* Extended `ActiveRecord::Base#cache_key` to take an optional list of timestamp
attributes of which the highest will be used. ([Commit](https://github.com/rails/rails/commit/e94e97ca796c0759d8fcb8f946a3bbc60252d329))
* Added `ActiveRecord::Base#enum` for declaring enum attributes where the values
map to integers in the database, but can be queried by
name. ([Commit](https://github.com/rails/rails/commit/db41eb8a6ea88b854bf5cd11070ea4245e1639c5))
* Type cast json values on write, so that the value is consistent with reading
from the database. ([Pull Request](https://github.com/rails/rails/pull/12643))
* Type cast hstore values on write, so that the value is consistent
with reading from the database. ([Commit](https://github.com/rails/rails/commit/5ac2341fab689344991b2a4817bd2bc8b3edac9d))
* Make `next_migration_number` accessible for third party
generators. ([Pull Request](https://github.com/rails/rails/pull/12407))
* Calling `update_attributes` will now throw an `ArgumentError` whenever it
gets a `nil` argument. More specifically, it will throw an error if the
argument that it gets passed does not respond to to
`stringify_keys`. ([Pull Request](https://github.com/rails/rails/pull/9860))
* `CollectionAssociation#first`/`#last` (e.g. `has_many`) use a `LIMIT`ed
query to fetch results rather than loading the entire
collection. ([Pull Request](https://github.com/rails/rails/pull/12137))
* `inspect` on Active Record model classes does not initiate a new
connection. This means that calling `inspect`, when the database is missing,
will no longer raise an exception. ([Pull Request](https://github.com/rails/rails/pull/11014))
* Removed column restrictions for `count`, let the database raise if the SQL is
invalid. ([Pull Request](https://github.com/rails/rails/pull/10710))
* Rails now automatically detects inverse associations. If you do not set the
`:inverse_of` option on the association, then Active Record will guess the
inverse association based on heuristics. ([Pull Request](https://github.com/rails/rails/pull/10886))
* Handle aliased attributes in ActiveRecord::Relation. When using symbol keys,
ActiveRecord will now translate aliased attribute names to the actual column
name used in the database. ([Pull Request](https://github.com/rails/rails/pull/7839))
* The ERB in fixture files is no longer evaluated in the context of the main
object. Helper methods used by multiple fixtures should be defined on modules
included in `ActiveRecord::FixtureSet.context_class`. ([Pull Request](https://github.com/rails/rails/pull/13022))
* Don't create or drop the test database if RAILS_ENV is specified explicitly.
Active Model
------------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/activemodel/CHANGELOG.md)
for detailed changes.
### Deprecations
* Deprecate `Validator#setup`. This should be done manually now in the
validator's constructor. ([Commit](https://github.com/rails/rails/commit/7d84c3a2f7ede0e8d04540e9c0640de7378e9b3a))
### Notable changes
* Added new API methods `reset_changes` and `changes_applied` to
`ActiveModel::Dirty` that control changes state.
Active Support
--------------
Please refer to the
[Changelog](https://github.com/rails/rails/blob/4-1-stable/activesupport/CHANGELOG.md)
for detailed changes.
### Removals
* Removed `MultiJSON` dependency. As a result, `ActiveSupport::JSON.decode`
no longer accepts an options hash for `MultiJSON`. ([Pull Request](https://github.com/rails/rails/pull/10576) / [More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
* Removed support for the `encode_json` hook used for encoding custom objects into
JSON. This feature has been extracted into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder)
gem.
([Related Pull Request](https://github.com/rails/rails/pull/12183) /
[More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
* Removed deprecated `ActiveSupport::JSON::Variable` with no replacement.
* Removed deprecated `String#encoding_aware?` core extensions (`core_ext/string/encoding`).
* Removed deprecated `Module#local_constant_names` in favor of `Module#local_constants`.
* Removed deprecated `DateTime.local_offset` in favor of `DateTime.civil_from_format`.
* Removed deprecated `Logger` core extensions (`core_ext/logger.rb`).
* Removed deprecated `Time#time_with_datetime_fallback`, `Time#utc_time` and
`Time#local_time` in favor of `Time#utc` and `Time#local`.
* Removed deprecated `Hash#diff` with no replacement.
* Removed deprecated `Date#to_time_in_current_zone` in favor of `Date#in_time_zone`.
* Removed deprecated `Proc#bind` with no replacement.
* Removed deprecated `Array#uniq_by` and `Array#uniq_by!`, use native
`Array#uniq` and `Array#uniq!` instead.
* Removed deprecated `ActiveSupport::BasicObject`, use
`ActiveSupport::ProxyObject` instead.
* Removed deprecated `BufferedLogger`, use `ActiveSupport::Logger` instead.
* Removed deprecated `assert_present` and `assert_blank` methods, use `assert
object.blank?` and `assert object.present?` instead.
### Deprecations
* Deprecated `Numeric#{ago,until,since,from_now}`, the user is expected to
explicitly convert the value into an AS::Duration, i.e. `5.ago` => `5.seconds.ago`
([Pull Request](https://github.com/rails/rails/pull/12389))
* Deprecated the require path `active_support/core_ext/object/to_json`. Require
`active_support/core_ext/object/json` instead. ([Pull Request](https://github.com/rails/rails/pull/12203))
* Deprecated `ActiveSupport::JSON::Encoding::CircularReferenceError`. This feature
has been extracted into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder)
gem.
([Pull Request](https://github.com/rails/rails/pull/12785) /
[More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
* Deprecated `ActiveSupport.encode_big_decimal_as_string` option. This feature has
been extracetd into the [activesupport-json_encoder](https://github.com/rails/activesupport-json_encoder)
gem.
([Pull Request](https://github.com/rails/rails/pull/13060) /
[More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
### Notable changes
* `ActiveSupport`'s JSON encoder has been rewritten to take advantage of the
JSON gem rather than doing custom encoding in pure-Ruby.
([Pull Request](https://github.com/rails/rails/pull/12183) /
[More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
* Improved compatibility with the JSON gem.
([Pull Request](https://github.com/rails/rails/pull/12862) /
[More Details](upgrading_ruby_on_rails.html#changes-in-json-handling))
* Added `ActiveSupport::Testing::TimeHelpers#travel` and `#travel_to`. These
methods change current time to the given time or time difference by stubbing
`Time.now` and
`Date.today`. ([Pull Request](https://github.com/rails/rails/pull/12824))
* Added `Numeric#in_milliseconds`, like `1.hour.in_milliseconds`, so we can feed
them to JavaScript functions like
`getTime()`. ([Commit](https://github.com/rails/rails/commit/423249504a2b468d7a273cbe6accf4f21cb0e643))
* Added `Date#middle_of_day`, `DateTime#middle_of_day` and `Time#middle_of_day`
methods. Also added `midday`, `noon`, `at_midday`, `at_noon` and
`at_middle_of_day` as
aliases. ([Pull Request](https://github.com/rails/rails/pull/10879))
* Added `String#remove(pattern)` as a short-hand for the common pattern of
`String#gsub(pattern,'')`. ([Commit](https://github.com/rails/rails/commit/5da23a3f921f0a4a3139495d2779ab0d3bd4cb5f))
* Removed 'cow' => 'kine' irregular inflection from default
inflections. ([Commit](https://github.com/rails/rails/commit/c300dca9963bda78b8f358dbcb59cabcdc5e1dc9))
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. Kudos to all of them.