Rails 5.2 Generate Master Key

  

Option 2: create a RAILSMASTERKEY ENV variable. Rails will detect it and use it as your master key, e.g. In heroku: heroku config:set RAILSMASTERKEY= your-master-key-here. $ heroku config:set RAILSMASTERKEY=your-master-key Example: $ heroku config:set RAILSMASTERKEY=123456789 (The are placeholders) Rails will detect this variable and use it as your master key (instead of looking for it in master.key file).

  1. Rails 5.2 Generate Master Key Chain
  2. Rails Generate Controller
  3. Rails 5.2 Generate Master Key Lock
  4. Rails Generate Model Foreign Key

1 Upgrading to Rails 5.1

If you're upgrading an existing application, it's a great idea to have good testcoverage before going in. You should also first upgrade to Rails 5.0 in case youhaven't and make sure your application still runs as expected before attemptingan update to Rails 5.1. A list of things to watch out for when upgrading isavailable in theUpgrading Ruby on Railsguide.

2 Major Features

2.1 Yarn Support

Rails 5.1 allows managing JavaScript dependenciesfrom NPM via Yarn. This will make it easy to use libraries like React, VueJSor any other library from NPM world. The Yarn support is integrated withthe asset pipeline so that all dependencies will work seamlessly with theRails 5.1 app.

2.2 Optional Webpack support

Rails apps can integrate with Webpack, a JavaScriptasset bundler, more easily using the new Webpackergem. Use the --webpack flag when generating new applications to enable Webpackintegration.

This is fully compatible with the asset pipeline, which you can continue to use forimages, fonts, sounds, and other assets. You can even have some JavaScript codemanaged by the asset pipeline, and other code processed via Webpack. All of this is managedby Yarn, which is enabled by default.

2.3 jQuery no longer a default dependency

jQuery was required by default in earlier versions of Rails to provide featureslike data-remote, data-confirm and other parts of Rails' Unobtrusive JavaScriptofferings. It is no longer required, as the UJS has been rewritten to use plain,vanilla JavaScript. This code now ships inside of Action View asrails-ujs.

You can still use jQuery if needed, but it is no longer required by default.

2.4 System tests

Rails 5.1 has baked-in support for writing Capybara tests, in the form ofSystem tests. You no longer need to worry about configuring Capybara anddatabase cleaning strategies for such tests. Rails 5.1 provides a wrapperfor running tests in Chrome with additional features such as failurescreenshots.

2.5 Encrypted secrets

Rails now allows management of application secrets in a secure way,inspired by the sekrets gem.

Run bin/rails secrets:setup to setup a new encrypted secrets file. This willalso generate a master key, which must be stored outside of the repository. Thesecrets themselves can then be safely checked into the revision control system,in an encrypted form.

Secrets will be decrypted in production, using a key stored either in theRAILS_MASTER_KEY environment variable, or in a key file.

2.6 Parameterized mailers

Allows specifying common parameters used for all methods in a mailer class inorder to share instance variables, headers and other common setup.

2.7 Direct & resolved routes

Rails 5.1 adds two new methods, resolve and direct, to the routingDSL. The resolve method allows customizing polymorphic mapping of models.

This will generate the singular URL /basket instead of the usual /baskets/:id.

The direct method allows creation of custom URL helpers.

The return value of the block must be a valid argument for the url_formethod. So, you can pass a valid string URL, Hash, Array, anActive Model instance, or an Active Model class.

2.8 Unification of form_for and form_tag into form_with

Before Rails 5.1, there were two interfaces for handling HTML forms:form_for for model instances and form_tag for custom URLs.

Rails 5.1 combines both of these interfaces with form_with, andcan generate form tags based on URLs, scopes or models.

Using just a URL:

Adding a scope prefixes the input field names:

Rails 5.2 Generate Master Key Chain

Using a model infers both the URL and scope:

An existing model makes an update form and fills out field values:

3 Incompatibilities

The following changes may require immediate action upon upgrade.

3.1 Transactional tests with multiple connections

Rails Generate Controller

Transactional tests now wrap all Active Record connections in databasetransactions.

When a test spawns additional threads, and those threads obtain databaseconnections, those connections are now handled specially:

The threads will share a single connection, which is inside the managedtransaction. This ensures all threads see the database in the samestate, ignoring the outermost transaction. Previously, such additionalconnections were unable to see the fixture rows, for example.

When a thread enters a nested transaction, it will temporarily obtainexclusive use of the connection, to maintain isolation.

If your tests currently rely on obtaining a separate,outside-of-transaction, connection in a spawned thread, you'll need toswitch to more explicit connection management.

If your tests spawn threads and those threads interact while also usingexplicit database transactions, this change may introduce a deadlock.

The easy way to opt out of this new behavior is to disable transactionaltests on any test cases it affects.

4 Railties

Please refer to the Changelog for detailed changes.

4.1 Removals

  • Remove deprecated config.static_cache_control.(commit)

  • Remove deprecated config.serve_static_files.(commit)

  • Remove deprecated file rails/rack/debugger.(commit)

  • Remove deprecated tasks: rails:update, rails:template, rails:template:copy,rails:update:configs and rails:update:bin.(commit)

  • Remove deprecated CONTROLLER environment variable for routes task.(commit)

  • Remove -j (--javascript) option from rails new command.(Pull Request)

4.2 Notable changes

  • Added a shared section to config/secrets.yml that will be loaded for allenvironments.(commit)

  • The config file config/secrets.yml is now loaded in with all keys as symbols.(Pull Request)

  • Removed jquery-rails from default stack. rails-ujs, which is shippedwith Action View, is included as default UJS adapter.(Pull Request)

  • Add Yarn support in new apps with a yarn binstub and package.json.(Pull Request)

  • Add Webpack support in new apps via the --webpack option, which will delegateto the rails/webpacker gem.(Pull Request)

  • Initialize Git repo when generating new app, if option --skip-git is notprovided.(Pull Request)

  • Add encrypted secrets in config/secrets.yml.enc.(Pull Request)

  • Display railtie class name in rails initializers.(Pull Request)

5 Action Cable

Please refer to the Changelog for detailed changes.

5.1 Notable changes

  • Added support for channel_prefix to Redis and evented Redis adaptersin cable.yml to avoid name collisions when using the same Redis serverwith multiple applications.(Pull Request)

  • Add ActiveSupport::Notifications hook for broadcasting data.(Pull Request)

6 Action Pack

Please refer to the Changelog for detailed changes.

6.1 Removals

  • Removed support for non-keyword arguments in #process, #get, #post,#patch, #put, #delete, and #head for the ActionDispatch::IntegrationTestand ActionController::TestCase classes.(Commit,Commit)

  • Removed deprecated ActionDispatch::Callbacks.to_prepare andActionDispatch::Callbacks.to_cleanup.(Commit)

  • Removed deprecated methods related to controller filters.(Commit)

  • Removed deprecated support to :text and :nothing in render.(Commit, Commit)

  • Removed deprecated support for calling HashWithIndifferentAccess methods on ActionController::Parameters.(Commit)

6.2 Deprecations

  • Deprecated config.action_controller.raise_on_unfiltered_parameters.It doesn't have any effect in Rails 5.1.(Commit)

6.3 Notable changes

  • Added the direct and resolve methods to the routing DSL.(Pull Request)

  • Added a new ActionDispatch::SystemTestCase class to write system tests inyour applications.(Pull Request)

7 Action View

Please refer to the Changelog for detailed changes.

7.1 Removals

  • Removed deprecated #original_exception in ActionView::Template::Error.(commit)

  • Remove the option encode_special_chars misnomer from strip_tags.(Pull Request)

7.2 Deprecations

  • Deprecated Erubis ERB handler in favor of Erubi.(Pull Request)

7.3 Notable changes

  • Raw template handler (the default template handler in Rails 5) now outputsHTML-safe strings.(commit)

  • Change datetime_field and datetime_field_tag to generate datetime-localfields.(Pull Request)

  • New Builder-style syntax for HTML tags (tag.div, tag.br, etc.)(Pull Request)

  • Add form_with to unify form_tag and form_for usage.(Pull Request)

  • Add check_parameters option to current_page?.(Pull Request)

Download

8 Action Mailer

Please refer to the Changelog for detailed changes.

8.1 Notable changes

  • Allowed setting custom content type when attachments are includedand body is set inline.(Pull Request)

  • Allowed passing lambdas as values to the default method.(Commit)

  • Added support for parameterized invocation of mailers to share before filters and defaultsbetween different mailer actions.(Commit)

  • Passed the incoming arguments to the mailer action to process.action_mailer event underan args key.(Pull Request)

9 Active Record

Please refer to the Changelog for detailed changes.

9.1 Removals

  • Removed support for passing arguments and block at the same time toActiveRecord::QueryMethods#select.(Commit)

  • Removed deprecated activerecord.errors.messages.restrict_dependent_destroy.one andactiverecord.errors.messages.restrict_dependent_destroy.many i18n scopes.(Commit)

  • Removed deprecated force reload argument in singular and collection association readers.(Commit)

  • Removed deprecated support for passing a column to #quote.(Commit)

  • Removed deprecated name arguments from #tables.(Commit)

  • Removed deprecated behavior of #tables and #table_exists? to return tables and viewsto return only tables and not views.(Commit)

  • Removed deprecated original_exception argument in ActiveRecord::StatementInvalid#initializeand ActiveRecord::StatementInvalid#original_exception.(Commit)

  • Removed deprecated support of passing a class as a value in a query.(Commit)

  • Removed deprecated support to query using commas on LIMIT.(Commit)

  • Removed deprecated conditions parameter from #destroy_all.(Commit)

  • Removed deprecated conditions parameter from #delete_all.(Commit)

  • Removed deprecated method #load_schema_for in favor of #load_schema.(Commit)

  • Removed deprecated #raise_in_transactional_callbacks configuration.(Commit)

  • Removed deprecated #use_transactional_fixtures configuration.(Commit)

9.2 Deprecations

  • Deprecated error_on_ignored_order_or_limit flag in favor oferror_on_ignored_order.(Commit)

  • Deprecated sanitize_conditions in favor of sanitize_sql.(Pull Request)

  • Deprecated supports_migrations? on connection adapters.(Pull Request)

  • Deprecated Migrator.schema_migrations_table_name, use SchemaMigration.table_name instead.(Pull Request)

  • Deprecated using #quoted_id in quoting and type casting.(Pull Request)

  • Deprecated passing default argument to #index_name_exists?.(Pull Request)

9.3 Notable changes

  • Change Default Primary Keys to BIGINT.(Pull Request)

  • Virtual/generated column support for MySQL 5.7.5+ and MariaDB 5.2.0+.(Commit)

  • Added support for limits in batch processing.(Commit)

  • Transactional tests now wrap all Active Record connections in databasetransactions.(Pull Request)

  • Skipped comments in the output of mysqldump command by default.(Pull Request)

  • Fixed ActiveRecord::Relation#count to use Ruby's Enumerable#count for countingrecords when a block is passed as argument instead of silently ignoring thepassed block.(Pull Request)

  • Pass '-v ON_ERROR_STOP=1' flag with psql command to not suppress SQL errors.(Pull Request)

  • Add ActiveRecord::Base.connection_pool.stat.(Pull Request)

  • Inheriting directly from ActiveRecord::Migration raises an error.Specify the Rails version for which the migration was written for.(Commit)

  • An error is raised when through association has ambiguous reflection name.(Commit)

10 Active Model

Please refer to the Changelog for detailed changes.

10.1 Removals

  • Removed deprecated methods in ActiveModel::Errors.(commit)

  • Removed deprecated :tokenizer option in the length validator.(commit)

  • Remove deprecated behavior that halts callbacks when the return value is false.(commit)

10.2 Notable changes

  • The original string assigned to a model attribute is no longer incorrectlyfrozen.(Pull Request)

11 Active Job

Please refer to the Changelog for detailed changes.

11.1 Removals

  • Removed deprecated support to passing the adapter class to .queue_adapter.(commit)

  • Removed deprecated #original_exception in ActiveJob::DeserializationError.(commit)

11.2 Notable changes

  • Added declarative exception handling via ActiveJob::Base.retry_on and ActiveJob::Base.discard_on.(Pull Request)

  • Yield the job instance so you have access to things like job.arguments onthe custom logic after retries fail.(commit)

12 Active Support

Please refer to the Changelog for detailed changes.

12.1 Removals

  • Removed the ActiveSupport::Concurrency::Latch class.(Commit)

  • Removed halt_callback_chains_on_return_false.(Commit)

  • Removed deprecated behavior that halts callbacks when the return is false.(Commit)

12.2 Deprecations

  • The top level HashWithIndifferentAccess class has been softly deprecatedin favor of the ActiveSupport::HashWithIndifferentAccess one.(Pull Request)

  • Deprecated passing string to :if and :unless conditional options on set_callback and skip_callback.(Commit)

12.3 Notable changes

  • Fixed duration parsing and traveling to make it consistent across DST changes.(Commit,Pull Request)

  • Updated Unicode to version 9.0.0.(Pull Request)

  • Add Duration#before and #after as aliases for #ago and #since.(Pull Request)

  • Added Module#delegate_missing_to to delegate method calls notdefined for the current object to a proxy object.(Pull Request)

  • Added Date#all_day which returns a range representing the whole dayof the current date & time.(Pull Request)

  • Introduced the assert_changes and assert_no_changes methods for tests.(Pull Request)

  • The travel and travel_to methods now raise on nested calls.(Pull Request)

  • Update DateTime#change to support usec and nsec.(Pull Request)

13 Credits

See thefull list of contributors to Rails forthe many people who spent many hours making Rails, the stable and robustframework it is. Kudos to all of them.

Feedback

You're encouraged to help improve the quality of this guide.

Please contribute if you see any typos or factual errors. To get started, you can read our documentation contributions section.

You may also find incomplete content or stuff that is not up to date. Please do add any missing documentation for master. Make sure to check Edge Guides first to verify if the issues are already fixed or not on the master branch. Check the Ruby on Rails Guides Guidelines for style and conventions.

If for whatever reason you spot something to fix but cannot patch it yourself, please open an issue.

And last but not least, any kind of discussion regarding Ruby on Rails documentation is very welcome on the rubyonrails-docs mailing list.

1 Upgrading to Rails 5.2

If you're upgrading an existing application, it's a great idea to have good testcoverage before going in. You should also first upgrade to Rails 5.1 in case youhaven't and make sure your application still runs as expected before attemptingan update to Rails 5.2. A list of things to watch out for when upgrading isavailable in theUpgrading Ruby on Railsguide.

2 Major Features

2.1 Active Storage

Active Storagefacilitates uploading files to a cloud storage service likeAmazon S3, Google Cloud Storage, or Microsoft Azure Storage and attachingthose files to Active Record objects. It comes with a local disk-based servicefor development and testing and supports mirroring files to subordinateservices for backups and migrations.You can read more about Active Storage in theActive Storage Overview guide.

2.2 Redis Cache Store

Rails 5.2 ships with built-in Redis cache store.You can read more about this in theCaching with Rails: An Overviewguide.

2.3 HTTP/2 Early Hints

Rails 5.2 supports HTTP/2 Early Hints.To start the server with Early Hints enabled pass --early-hintsto bin/rails server.

2.4 Credentials

Added config/credentials.yml.enc file to store production app secrets.It allows saving any authentication credentials for third-party servicesdirectly in repository encrypted with a key in the config/master.key file orthe RAILS_MASTER_KEY environment variable.This will eventually replace Rails.application.secrets and the encryptedsecrets introduced in Rails 5.1.Furthermore, Rails 5.2opens API underlying Credentials,so you can easily deal with other encrypted configurations, keys, and files.You can read more about this in theSecuring Rails Applicationsguide.

2.5 Content Security Policy

Rails 5.2 ships with a new DSL that allows you to configure aContent Security Policyfor your application. You can configure a global default policy and thenoverride it on a per-resource basis and even use lambdas to inject per-requestvalues into the header such as account subdomains in a multi-tenant application.You can read more about this in theSecuring Rails Applicationsguide.

3 Railties

Please refer to the Changelog for detailed changes.

3.1 Deprecations

  • Deprecate capify! method in generators and templates.(Pull Request)

  • Passing the environment's name as a regular argument to therails dbconsole and rails console commands is deprecated.The -e option should be used instead.(Commit)

  • Deprecate using subclass of Rails::Application to start the Rails server.(Pull Request)

  • Deprecate after_bundle callback in Rails plugin templates.(Pull Request)

3.2 Notable changes

  • Added a shared section to config/database.yml that will be loaded forall environments.(Pull Request)

  • Add railtie.rb to the plugin generator.(Pull Request)

  • Clear screenshot files in tmp:clear task.(Pull Request)

  • Skip unused components when running bin/rails app:update.If the initial app generation skipped Action Cable, Active Record etc.,the update task honors those skips too.(Pull Request)

  • Allow passing a custom connection name to the rails dbconsolecommand when using a 3-level database configuration.Example: bin/rails dbconsole -c replica.(Commit)

  • Properly expand shortcuts for environment's name running the consoleand dbconsole commands.(Commit)

  • Add bootsnap to default Gemfile.(Pull Request)

  • Support - as a platform-agnostic way to run a script from stdin withrails runner(Pull Request)

  • Add ruby x.x.x version to Gemfile and create .ruby-versionroot file containing the current Ruby version when new Rails applicationsare created.(Pull Request)

  • Add --skip-action-cable option to the plugin generator.(Pull Request)

  • Add git_source to Gemfile for plugin generator.(Pull Request)

  • Skip unused components when running bin/rails in Rails plugin.(Commit)

  • Optimize indentation for generator actions.(Pull Request)

  • Optimize routes indentation.(Pull Request)

  • Add --skip-yarn option to the plugin generator.(Pull Request)

  • Support multiple versions arguments for gem method of Generators.(Pull Request)

  • Derive secret_key_base from the app name in development and testenvironments.(Pull Request)

  • Add mini_magick to default Gemfile as comment.(Pull Request)

  • rails new and rails plugin new get Active Storage by default. Add ability to skip Active Storage with --skip-active-storage and do so automatically when --skip-active-record is used.(Pull Request)

4 Action Cable

Please refer to the Changelog for detailed changes.

4.1 Removals

  • Removed deprecated evented redis adapter.(Commit)

4.2 Notable changes

  • Generator product key windows 10 pro. Add support for host, port, db and password options in cable.yml(Pull Request)

  • Hash long stream identifiers when using PostgreSQL adapter.(Pull Request)

5 Action Pack

Please refer to the Changelog for detailed changes.

5.1 Removals

  • Remove deprecated ActionController::ParamsParser::ParseError.(Commit)

5.2 Deprecations

  • Deprecate #success?, #missing? and #error? aliases ofActionDispatch::TestResponse.(Pull Request)

5.3 Notable changes

  • Add support for recyclable cache keys with fragment caching.(Pull Request)

  • Change the cache key format for fragments to make it easier to debug keychurn.(Pull Request)

  • AEAD encrypted cookies and sessions with GCM.(Pull Request)

  • Protect from forgery by default.(Pull Request)

  • Enforce signed/encrypted cookie expiry server side.(Pull Request)

  • Cookies :expires option supports ActiveSupport::Duration object.(Pull Request)

  • Use Capybara registered :puma server config.(Pull Request)

  • Simplify cookies middleware with key rotation support.(Pull Request)

  • Add ability to enable Early Hints for HTTP/2.(Pull Request)

  • Add headless chrome support to System Tests.(Pull Request)

  • Add :allow_other_host option to redirect_back method.(Pull Request)

  • Make assert_recognizes to traverse mounted engines.(Pull Request)

  • Add DSL for configuring Content-Security-Policy header.(Pull Request,Commit,Commit)

  • Register most popular audio/video/font mime types supported by modernbrowsers.(Pull Request)

  • Changed the default system test screenshot output from inline to simple.(Commit)

  • Add headless firefox support to System Tests.(Pull Request)

  • Add secure X-Download-Options and X-Permitted-Cross-Domain-Policies todefault headers set.(Commit)

  • Changed the system tests to set Puma as default server only when theuser haven't specified manually another server.(Pull Request)

  • Add Referrer-Policy header to default headers set.(Commit)

  • Matches behavior of Hash#each in ActionController::Parameters#each.(Pull Request)

  • Add support for automatic nonce generation for Rails UJS.(Commit)

  • Update the default HSTS max-age value to 31536000 seconds (1 year)to meet the minimum max-age requirement for https://hstspreload.org/.(Commit)

  • Add alias method to_hash to to_h for cookies.Add alias method to_h to to_hash for session.(Commit)

6 Action View

Please refer to the Changelog for detailed changes.

6.1 Removals

  • Remove deprecated Erubis ERB handler.(Commit)

6.2 Deprecations

  • Deprecate image_alt helper which used to add default alt text tothe images generated by image_tag.(Pull Request)

6.3 Notable changes

  • Add :json type to auto_discovery_link_tag to supportJSON Feeds.(Pull Request)

  • Add srcset option to image_tag helper.(Pull Request)

  • Fix issues with field_error_proc wrapping optgroup andselect divider option.(Pull Request)

  • Change form_with to generate ids by default.(Commit)

  • Add preload_link_tag helper.(Pull Request)

  • Allow the use of callable objects as group methods for grouped selects.(Pull Request)

7 Action Mailer

Please refer to the Changelog for detailed changes.

7.1 Notable changes

  • Allow Action Mailer classes to configure their delivery job.(Pull Request)

  • Add assert_enqueued_email_with test helper.(Pull Request)

8 Active Record

Please refer to the Changelog for detailed changes.

8.1 Removals

  • Remove deprecated #migration_keys.(Pull Request)

  • Remove deprecated support to quoted_id when typecastingan Active Record object.(Commit)

  • Remove deprecated argument default from index_name_exists?.(Commit)

  • Remove deprecated support to passing a class to :class_nameon associations.(Commit)

  • Remove deprecated methods initialize_schema_migrations_table andinitialize_internal_metadata_table.(Commit)

  • Remove deprecated method supports_migrations?.(Commit)

  • Remove deprecated method supports_primary_key?.(Commit)

  • Remove deprecated methodActiveRecord::Migrator.schema_migrations_table_name.(Commit)

  • Remove deprecated argument name from #indexes.(Commit)

  • Remove deprecated arguments from #verify!.(Commit)

  • Remove deprecated configuration .error_on_ignored_order_or_limit.(Commit)

  • Remove deprecated method #scope_chain.(Commit)

  • Remove deprecated method #sanitize_conditions.(Commit)

8.2 Deprecations

  • Deprecate supports_statement_cache?.(Pull Request)

  • Deprecate passing arguments and block at the same time tocount and sum in ActiveRecord::Calculations.(Pull Request)

  • Deprecate delegating to arel in Relation.(Pull Request)

  • Deprecate set_state method in TransactionState.(Commit)

  • Deprecate expand_hash_conditions_for_aggregates without replacement.(Commit)

8.3 Notable changes

  • When calling the dynamic fixture accessor method with no arguments, it nowreturns all fixtures of this type. Previously this method always returnedan empty array.(Pull Request)

  • Fix inconsistency with changed attributes when overridingActive Record attribute reader.(Pull Request)

  • Support Descending Indexes for MySQL.(Pull Request)

  • Fix bin/rails db:forward first migration.(Commit)

  • Raise error UnknownMigrationVersionError on the movement of migrationswhen the current migration does not exist.(Commit)

  • Respect SchemaDumper.ignore_tables in rake tasks fordatabases structure dump.(Pull Request)

  • Add ActiveRecord::Base#cache_version to support recyclable cache keys viathe new versioned entries in ActiveSupport::Cache. This also means thatActiveRecord::Base#cache_key will now return a stable key thatdoes not include a timestamp any more.(Pull Request)

  • Prevent creation of bind param if casted value is nil.(Pull Request)

  • Use bulk INSERT to insert fixtures for better performance.(Pull Request)

  • Merging two relations representing nested joins no longer transformsthe joins of the merged relation into LEFT OUTER JOIN.(Pull Request)

  • Fix transactions to apply state to child transactions.Previously, if you had a nested transaction and the outer transaction wasrolledback, the record from the inner transaction would still be markedas persisted. It was fixed by applying the state of the parenttransaction to the child transaction when the parent transaction isrolledback. This will correctly mark records from the inner transactionas not persisted.(Commit)

  • Fix eager loading/preloading association with scope including joins.(Pull Request)

  • Prevent errors raised by sql.active_record notification subscribersfrom being converted into ActiveRecord::StatementInvalid exceptions.(Pull Request)

  • Skip query caching when working with batches of records(find_each, find_in_batches, in_batches).(Commit)

  • Change sqlite3 boolean serialization to use 1 and 0.SQLite natively recognizes 1 and 0 as true and false, but does not nativelyrecognize 't' and 'f' as was previously serialized.(Pull Request)

  • Values constructed using multi-parameter assignment will now use thepost-type-cast value for rendering in single-field form inputs.(Commit)

  • ApplicationRecord is no longer generated when generating models. If youneed to generate it, it can be created with rails g application_record.(Pull Request)

  • Relation#or now accepts two relations who have different values forreferences only, as references can be implicitly called by where.(Commit)

  • When using Relation#or, extract the common conditions andput them before the OR condition.(Pull Request)

  • Add binary fixture helper method.(Pull Request)

  • Automatically guess the inverse associations for STI.(Pull Request)

  • Add new error class LockWaitTimeout which will be raisedwhen lock wait timeout exceeded.(Pull Request)

  • Update payload names for sql.active_record instrumentation to bemore descriptive.(Pull Request)

  • Use given algorithm while removing index from database.(Pull Request)

  • Passing a Set to Relation#where now behaves the same as passingan array.(Commit)

  • PostgreSQL tsrange now preserves subsecond precision.(Pull Request)

  • Raises when calling lock! in a dirty record.(Commit)

  • Fixed a bug where column orders for an index weren't written todb/schema.rb when using the sqlite adapter.(Pull Request)

  • Fix bin/rails db:migrate with specified VERSION.bin/rails db:migrate with empty VERSION behaves as without VERSION.Check a format of VERSION: Allow a migration version numberor name of a migration file. Raise error if format of VERSION is invalid.Raise error if target migration doesn't exist.(Pull Request)

  • Add new error class StatementTimeout which will be raisedwhen statement timeout exceeded.(Pull Request)

  • update_all will now pass its values to Type#cast before passing them toType#serialize. This means that update_all(foo: 'true') will properlypersist a boolean.(Commit)

  • Require raw SQL fragments to be explicitly marked when used inrelation query methods.(Commit,Commit)

  • Add #up_only to database migrations for code that is only relevant whenmigrating up, e.g. populating a new column.(Pull Request)

  • Add new error class QueryCanceled which will be raisedwhen canceling statement due to user request.(Pull Request)

  • Don't allow scopes to be defined which conflict with instance methodson Relation.(Pull Request)

  • Add support for PostgreSQL operator classes to add_index.(Pull Request)

  • Log database query callers.(Pull Request,Pull Request,Pull Request)

  • Undefine attribute methods on descendants when resetting column information.(Pull Request)

  • Using subselect for delete_all with limit or offset.(Commit)

  • Fixed inconsistency with first(n) when used with limit().The first(n) finder now respects the limit(), making it consistentwith relation.to_a.first(n), and also with the behavior of last(n).(Pull Request)

  • Fix nested has_many :through associations on unpersisted parent instances.(Commit)

  • Take into account association conditions when deleting through records.(Commit)

  • Don't allow destroyed object mutation after save or save! is called.(Commit)

  • Fix relation merger issue with left_outer_joins.(Pull Request)

  • Support for PostgreSQL foreign tables.(Pull Request)

  • Clear the transaction state when an Active Record object is duped.(Pull Request)

  • Fix not expanded problem when passing an Array object as argumentto the where method using composed_of column.(Pull Request)

  • Make reflection.klass raise if polymorphic? not to be misused.(Commit)

  • Fix #columns_for_distinct of MySQL and PostgreSQL to makeActiveRecord::FinderMethods#limited_ids_for use correct primary key valueseven if ORDER BY columns include other table's primary key.(Commit)

  • Fix dependent: :destroy issue for has_one/belongs_to relationship wherethe parent class was getting deleted when the child was not.(Commit)

  • Idle database connections (previously just orphaned connections) are nowperiodically reaped by the connection pool reaper.(Commit)

9 Active Model

Please refer to the Changelog for detailed changes.

9.1 Notable changes

  • Fix methods #keys, #values in ActiveModel::Errors.Change #keys to only return the keys that don't have empty messages.Change #values to only return the not empty values.(Pull Request)

  • Add method #merge! for ActiveModel::Errors.(Pull Request)

  • Allow passing a Proc or Symbol to length validator options.(Pull Request)

  • Execute ConfirmationValidator validation when _confirmation's valueis false.(Pull Request)

  • Models using the attributes API with a proc default can now be marshalled.(Commit)

  • Do not lose all multiple :includes with options in serialization.(Commit)

10 Active Support

Please refer to the Changelog for detailed changes.

10.1 Removals

  • Remove deprecated :if and :unless string filter for callbacks.(Commit)

  • Remove deprecated halt_callback_chains_on_return_false option.(Commit)

10.2 Deprecations

  • Deprecate Module#reachable? method.(Pull Request)

  • Deprecate secrets.secret_token.(Commit)

10.3 Notable changes

  • Add fetch_values for HashWithIndifferentAccess.(Pull Request)

  • Add support for :offset to Time#change.(Commit)

  • Add support for :offset and :zoneto ActiveSupport::TimeWithZone#change.(Commit)

  • Pass gem name and deprecation horizon to deprecation notifications.(Pull Request)

  • Add support for versioned cache entries. This enables the cache stores torecycle cache keys, greatly saving on storage in cases with frequent churn.Works together with the separation of #cache_key and #cache_versionin Active Record and its use in Action Pack's fragment caching.(Pull Request)

  • Add ActiveSupport::CurrentAttributes to provide a thread-isolatedattributes singleton. Primary use case is keeping all the per-requestattributes easily available to the whole system.(Pull Request)

  • #singularize and #pluralize now respect uncountables forthe specified locale.(Commit)

  • Add default option to class_attribute.(Pull Request)

  • Add Date#prev_occurring and Date#next_occurring to returnspecified next/previous occurring day of week.(Pull Request)

  • Add default option to module and class attribute accessors.(Pull Request)

  • Cache: write_multi.(Pull Request)

  • Default ActiveSupport::MessageEncryptor to use AES 256 GCM encryption.(Pull Request)

  • Add freeze_time helper which freezes time to Time.now in tests.(Pull Request)

  • Make the order of Hash#reverse_merge! consistentwith HashWithIndifferentAccess.(Pull Request)

  • Add purpose and expiry support to ActiveSupport::MessageVerifier andActiveSupport::MessageEncryptor.(Pull Request)

  • Update String#camelize to provide feedback when wrong option is passed.(Pull Request)

  • Module#delegate_missing_to now raises DelegationError if target is nil,similar to Module#delegate.(Pull Request)

  • Add ActiveSupport::EncryptedFile andActiveSupport::EncryptedConfiguration.(Pull Request)

  • Add config/credentials.yml.enc to store production app secrets.(Pull Request)

  • Add key rotation support to MessageEncryptor and MessageVerifier.(Pull Request)

  • Return an instance of HashWithIndifferentAccess fromHashWithIndifferentAccess#transform_keys.(Pull Request)

  • Hash#slice now falls back to Ruby 2.5+'s built-in definition if defined.(Commit)

  • IO#to_json now returns the to_s representation, rather thanattempting to convert to an array. This fixes a bug where IO#to_jsonwould raise an IOError when called on an unreadable object.(Pull Request)

  • Add same method signature for Time#prev_day and Time#next_dayin accordance with Date#prev_day, Date#next_day.Allows pass argument for Time#prev_day and Time#next_day.(Commit)

  • Add same method signature for Time#prev_month and Time#next_monthin accordance with Date#prev_month, Date#next_month.Allows pass argument for Time#prev_month and Time#next_month.(Commit)

  • Add same method signature for Time#prev_year and Time#next_yearin accordance with Date#prev_year, Date#next_year.Allows pass argument for Time#prev_year and Time#next_year.(Commit)

  • Fix acronym support in humanize.(Commit)

  • Allow Range#include? on TWZ ranges.(Pull Request)

  • Cache: Enable compression by default for values > 1kB.(Pull Request)

  • Redis cache store.(Pull Request,Pull Request)

  • Handle TZInfo::AmbiguousTime errors.(Pull Request)

  • MemCacheStore: Support expiring counters.(Commit)

  • Make ActiveSupport::TimeZone.all return only time zones that are inActiveSupport::TimeZone::MAPPING.(Pull Request)

  • Changed default behaviour of ActiveSupport::SecurityUtils.secure_compare,to make it not leak length information even for variable length string.Renamed old ActiveSupport::SecurityUtils.secure_compare tofixed_length_secure_compare, and started raising ArgumentError incase of length mismatch of passed strings.(Pull Request)

  • Use SHA-1 to generate non-sensitive digests, such as the ETag header.(Pull Request,Pull Request)

  • assert_changes will always assert that the expression changes,regardless of from: and to: argument combinations.(Pull Request)

  • Add missing instrumentation for read_multiin ActiveSupport::Cache::Store.(Pull Request)

  • Support hash as first argument in assert_difference.This allows to specify multiple numeric differences in the same assertion.(Pull Request)

  • Caching: MemCache and Redis read_multi and fetch_multi speedup.Read from the local in-memory cache before consulting the backend.(Commit)

11 Active Job

Please refer to the Changelog for detailed changes.

11.1 Notable changes

  • Allow block to be passed to ActiveJob::Base.discard_on to allow customhandling of discard jobs.(Pull Request)

12 Ruby on Rails Guides

Please refer to the Changelog for detailed changes.

12.1 Notable changes

  • AddThreading and Code Execution in RailsGuide.(Pull Request)

  • Add Active Storage Overview Guide.(Pull Request)

13 Credits

See thefull list of contributors to Railsfor the many people who spent many hours making Rails, the stable and robustframework it is. Kudos to all of them.

Feedback

You're encouraged to help improve the quality of this guide.

Rails 5.2 Generate Master Key Lock

Please contribute if you see any typos or factual errors. To get started, you can read our documentation contributions section.

You may also find incomplete content or stuff that is not up to date. Please do add any missing documentation for master. Make sure to check Edge Guides first to verify if the issues are already fixed or not on the master branch. Check the Ruby on Rails Guides Guidelines for style and conventions.

If for whatever reason you spot something to fix but cannot patch it yourself, please open an issue.

Rails Generate Model Foreign Key

And last but not least, any kind of discussion regarding Ruby on Rails documentation is very welcome on the rubyonrails-docs mailing list.