1. 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 guide.
2. Major Features
2.1. 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 to see all available features.
See the Upgrading Ruby on Rails guide on how to migrate existing applications to use this feature.
2.2. 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
:
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 guide on how to migrate existing applications to use this feature.
2.3. 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
:
request.variant = :tablet if request.user_agent =~ /iPad/
Respond to variants in the action just like you respond to formats:
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:
respond_to do |format|
format.js { render "trash" }
format.html.phone { redirect_to progress_path }
format.html.none { render "trash" }
end
2.4. Action Mailer Previews
Action Mailer previews provide a way to 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:
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 for a detailed write up.
2.5. Active Record enums
Declare an enum attribute where the values map to integers in the database, but can be queried by name.
class Conversation < ActiveRecord::Base
enum status: [ :active, :archived ]
end
conversation.archived!
conversation.active? # => false
conversation.status # => "archived"
Conversation.archived # => Relation for all archived Conversations
Conversation.statuses # => { "active" => 0, "archived" => 1 }
See its documentation for a detailed write up.
2.6. 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:
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
2.7. Module#concerning
A natural, low-ceremony way to separate responsibilities within a class:
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 for a detailed write up and the intended use cases.
2.8. 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
.
3. Railties
Please refer to the Changelog for detailed changes.
3.1. 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 ofActiveRecord::Generators::ActiveModel#update
.Removed deprecated
config.whiny_nils
option.Removed deprecated rake tasks for running tests:
rake test:uncommitted
andrake test:recent
.
3.2. Notable changes
The Spring application preloader 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)BACKTRACE
environment variable to show unfiltered backtraces for test failures. (Commit)Exposed
MiddlewareStack#unshift
to environment configuration. (Pull Request)Added
Application#message_verifier
method to return a message verifier. (Pull Request)The
test_help.rb
file which is required by the default generated test helper will automatically keep your test database up-to-date withdb/schema.rb
(ordb/structure.sql
). It raises an error if reloading the schema does not resolve all pending migrations. Opt out withconfig.active_record.maintain_test_schema = false
. (Pull Request)Introduce
Rails.gem_version
as a convenience method to returnGem::Version.new(Rails.version)
, suggesting a more reliable way to perform version comparison. (Pull Request)
4. Action Pack
Please refer to the Changelog for detailed changes.
4.1. Removals
Removed deprecated Rails application fallback for integration testing, set
ActionDispatch.test_app
instead.Removed deprecated
page_cache_extension
config.Removed deprecated
ActionController::RecordIdentifier
, useActionView::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 |
4.2. Notable changes
protect_from_forgery
also prevents cross-origin<script>
tags. Update your tests to usexhr :get, :foo, format: :js
instead ofget :foo, format: :js
. (Pull Request)#url_for
takes a hash with options inside an array. (Pull Request)Added
session#fetch
method fetch behaves similarly to Hash#fetch, with the exception that the returned value is always saved into the session. (Pull Request)Separated Action View completely from Action Pack. (Pull Request)
Log which keys were affected by deep munge. (Pull Request)
New config option
config.action_dispatch.perform_deep_munge
to opt out of params "deep munging" that was used to address security vulnerability CVE-2013-0155. (Pull Request)New config option
config.action_dispatch.cookies_serializer
for specifying a serializer for the signed and encrypted cookie jars. (Pull Requests 1, 2 / More Details)Added
render :plain
,render :html
andrender :body
. (Pull Request / More Details)
5. Action Mailer
Please refer to the Changelog for detailed changes.
5.1. Notable changes
Added mailer previews feature based on 37 Signals mail_view gem. (Commit)
Instrument the generation of Action Mailer messages. The time it takes to generate a message is written to the log. (Pull Request)
6. Active Record
Please refer to the Changelog for detailed changes.
6.1. Removals
Removed deprecated nil-passing to the following
SchemaCache
methods:primary_keys
,tables
,columns
andcolumns_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 ofbegin_transaction
with a: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 ofActiveRecord::Fixtures.default_fixture_model_name
.Removed deprecated
columns_for_remove
fromSchemaStatements
.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 fromRelation#count
.Removed deprecated methods
partial_updates
,partial_updates?
andpartial_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 the gem README for more info.Removed usage of
implicit_readonly
. Please usereadonly
method explicitly to mark records asreadonly
. (Pull Request)
6.2. Deprecations
Deprecated
quoted_locking_column
method, which isn't used anywhere.Deprecated
ConnectionAdapters::SchemaStatements#distinct
, as it is no longer used by internals. (Pull Request)Deprecated
rake db:test:*
tasks as the test database is now automatically maintained. See railties release notes. (Pull Request)Deprecate unused
ActiveRecord::Base.symbolized_base_class
andActiveRecord::Base.symbolized_sti_name
without replacement. Commit
6.3. Notable changes
- Default scopes are no longer overridden by chained conditions.
Before this change when you defined a default_scope
in a model
it was overridden by chained conditions in the same field. Now it
is merged like any other scope. More Details.
Added
ActiveRecord::Base.to_param
for convenient "pretty" URLs derived from a model's attribute or method. (Pull Request)Added
ActiveRecord::Base.no_touching
, which allows ignoring touch on models. (Pull Request)Unify boolean type casting for
MysqlAdapter
andMysql2Adapter
.type_cast
will return1
fortrue
and0
forfalse
. (Pull Request).unscope
now removes conditions specified indefault_scope
. (Commit)Added
ActiveRecord::QueryMethods#rewhere
which will overwrite an existing, named where condition. (Commit)Extended
ActiveRecord::Base#cache_key
to take an optional list of timestamp attributes of which the highest will be used. (Commit)Added
ActiveRecord::Base#enum
for declaring enum attributes where the values map to integers in the database, but can be queried by name. (Commit)Type cast JSON values on write, so that the value is consistent with reading from the database. (Pull Request)
Type cast hstore values on write, so that the value is consistent with reading from the database. (Commit)
Make
next_migration_number
accessible for third party generators. (Pull Request)Calling
update_attributes
will now throw anArgumentError
whenever it gets anil
argument. More specifically, it will throw an error if the argument that it gets passed does not respond tostringify_keys
. (Pull Request)CollectionAssociation#first
/#last
(e.g.has_many
) use aLIMIT
ed query to fetch results rather than loading the entire collection. (Pull Request)inspect
on Active Record model classes does not initiate a new connection. This means that callinginspect
, when the database is missing, will no longer raise an exception. (Pull Request)Removed column restrictions for
count
, let the database raise if the SQL is invalid. (Pull Request)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)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)
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)Don't create or drop the test database if RAILS_ENV is specified explicitly. (Pull Request)
Relation
no longer has mutator methods like#map!
and#delete_if
. Convert to anArray
by calling#to_a
before using these methods. (Pull Request)find_in_batches
,find_each
,Result#each
andEnumerable#index_by
now return anEnumerator
that can calculate its size. (Pull Request)scope
,enum
and Associations now raise on "dangerous" name conflicts. (Pull Request, Pull Request)second
throughfifth
methods act like thefirst
finder. (Pull Request)Make
touch
fire theafter_commit
andafter_rollback
callbacks. (Pull Request)Enable partial indexes for
sqlite >= 3.8.0
. (Pull Request)Make
change_column_null
revertible. (Commit)Added a flag to disable schema dump after migration. This is set to
false
by default in the production environment for new applications. (Pull Request)
7. Active Model
Please refer to the Changelog for detailed changes.
7.1. Deprecations
- Deprecate
Validator#setup
. This should be done manually now in the validator's constructor. (Commit)
7.2. Notable changes
Added new API methods
reset_changes
andchanges_applied
toActiveModel::Dirty
that control changes state.Ability to specify multiple contexts when defining a validation. (Pull Request)
attribute_changed?
now accepts a hash to check if the attribute was changed:from
and/or:to
a given value. (Pull Request)
8. Active Support
Please refer to the Changelog for detailed changes.
8.1. Removals
Removed
MultiJSON
dependency. As a result,ActiveSupport::JSON.decode
no longer accepts an options hash forMultiJSON
. (Pull Request / More Details)Removed support for the
encode_json
hook used for encoding custom objects into JSON. This feature has been extracted into the activesupport-json_encoder gem. (Related Pull Request / More Details)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 ofModule#local_constants
.Removed deprecated
DateTime.local_offset
in favor ofDateTime.civil_from_format
.Removed deprecated
Logger
core extensions (core_ext/logger.rb
).Removed deprecated
Time#time_with_datetime_fallback
,Time#utc_time
andTime#local_time
in favor ofTime#utc
andTime#local
.Removed deprecated
Hash#diff
with no replacement.Removed deprecated
Date#to_time_in_current_zone
in favor ofDate#in_time_zone
.Removed deprecated
Proc#bind
with no replacement.Removed deprecated
Array#uniq_by
andArray#uniq_by!
, use nativeArray#uniq
andArray#uniq!
instead.Removed deprecated
ActiveSupport::BasicObject
, useActiveSupport::ProxyObject
instead.Removed deprecated
BufferedLogger
, useActiveSupport::Logger
instead.Removed deprecated
assert_present
andassert_blank
methods, useassert object.blank?
andassert object.present?
instead.Remove deprecated
#filter
method for filter objects, use the corresponding method instead (e.g.#before
for a before filter).Removed 'cow' => 'kine' irregular inflection from default inflections. (Commit)
8.2. 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)Deprecated the require path
active_support/core_ext/object/to_json
. Requireactive_support/core_ext/object/json
instead. (Pull Request)Deprecated
ActiveSupport::JSON::Encoding::CircularReferenceError
. This feature has been extracted into the activesupport-json_encoder gem. (Pull Request / More Details)Deprecated
ActiveSupport.encode_big_decimal_as_string
option. This feature has been extracted into the activesupport-json_encoder gem. (Pull Request / More Details)Deprecate custom
BigDecimal
serialization. (Pull Request)
8.3. 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 / More Details)Improved compatibility with the JSON gem. (Pull Request / More Details)
Added
ActiveSupport::Testing::TimeHelpers#travel
and#travel_to
. These methods change current time to the given time or duration by stubbingTime.now
andDate.today
.Added
ActiveSupport::Testing::TimeHelpers#travel_back
. This method returns the current time to the original state, by removing the stubs added bytravel
andtravel_to
. (Pull Request)Added
Numeric#in_milliseconds
, like1.hour.in_milliseconds
, so we can feed them to JavaScript functions likegetTime()
. (Commit)Added
Date#middle_of_day
,DateTime#middle_of_day
andTime#middle_of_day
methods. Also addedmidday
,noon
,at_midday
,at_noon
andat_middle_of_day
as aliases. (Pull Request)Added
Date#all_week/month/quarter/year
for generating date ranges. (Pull Request)Added
Time.zone.yesterday
andTime.zone.tomorrow
. (Pull Request)Added
String#remove(pattern)
as a short-hand for the common pattern ofString#gsub(pattern,'')
. (Commit)Added
Hash#compact
andHash#compact!
for removing items with nil value from hash. (Pull Request)blank?
andpresent?
commit to return singletons. (Commit)Default the new
I18n.enforce_available_locales
config totrue
, meaningI18n
will make sure that all locales passed to it must be declared in theavailable_locales
list. (Pull Request)Introduce
Module#concerning
: a natural, low-ceremony way to separate responsibilities within a class. (Commit)Added
Object#presence_in
to simplify adding values to a permitted list. (Commit)
9. Credits
See the full list of contributors to Rails for the many people who spent many hours making Rails, the stable and robust framework it is. Kudos to all of them.