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-rw-r--r--guides/source/upgrading_ruby_on_rails.md136
1 files changed, 107 insertions, 29 deletions
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 05c46a9e76..59eddb6302 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -16,26 +16,41 @@ Before attempting to upgrade an existing application, you should be sure you hav
The best way to be sure that your application still works after upgrading is to have good test coverage before you start the process. If you don't have automated tests that exercise the bulk of your application, you'll need to spend time manually exercising all the parts that have changed. In the case of a Rails upgrade, that will mean every single piece of functionality in the application. Do yourself a favor and make sure your test coverage is good _before_ you start an upgrade.
+### The Upgrade Process
+
+When changing Rails versions, it's best to move slowly, one minor version at a time, in order to make good use of the deprecation warnings. Rails version numbers are in the form Major.Minor.Patch. Major and Minor versions are allowed to make changes to the public API, so this may cause errors in your application. Patch versions only include bug fixes, and don't change any public API.
+
+The process should go as follows:
+
+1. Write tests and make sure they pass.
+2. Move to the latest patch version after your current version.
+3. Fix tests and deprecated features.
+4. Move to the latest patch version of the next minor version.
+
+Repeat this process until you reach your target Rails version. Each time you move versions, you will need to change the Rails version number in the Gemfile (and possibly other gem versions) and run `bundle update`. Then run the Update task mentioned below to update configuration files, then run your tests.
+
+You can find a list of all released Rails versions [here](https://rubygems.org/gems/rails/versions).
+
### Ruby Versions
Rails generally stays close to the latest released Ruby version when it's released:
-* Rails 5 requires Ruby 2.2.1 or newer.
+* Rails 5 requires Ruby 2.2.2 or newer.
* Rails 4 prefers Ruby 2.0 and requires 1.9.3 or newer.
* Rails 3.2.x is the last branch to support Ruby 1.8.7.
* Rails 3 and above require Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially. You should upgrade as early as possible.
TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump straight to 1.9.3 for smooth sailing.
-### The Rake Task
+### The Update Task
-Rails provides the `rails:update` rake task. After updating the Rails version
-in the Gemfile, run this rake task.
+Rails provides the `app:update` task (`rails:update` on 4.2 and earlier). After updating the Rails version
+in the Gemfile, run this task.
This will help you with the creation of new files and changes of old files in an
interactive session.
```bash
-$ rake rails:update
+$ rails app:update
identical config/boot.rb
exist config
conflict config/routes.rb
@@ -53,28 +68,72 @@ Don't forget to review the difference, to see if there were any unexpected chang
Upgrading from Rails 4.2 to Rails 5.0
-------------------------------------
-### Halting callback chains by returning `false`
+### Ruby 2.2.2+
+
+From Ruby on Rails 5.0 onwards, Ruby 2.2.2+ is the only supported version.
+Make sure you are on Ruby 2.2.2 version or greater, before you proceed.
+
+### Active Record models now inherit from ApplicationRecord by default
+
+In Rails 4.2 an Active Record model inherits from `ActiveRecord::Base`. In Rails 5.0,
+all models inherit from `ApplicationRecord`.
-In Rails 4.2, when a 'before' callback returns `false` in ActiveRecord,
-ActiveModel and ActiveModel::Validations, then the entire callback chain
-is halted. In other words, successive 'before' callbacks are not executed,
-and neither is the action wrapped in callbacks.
+`ApplicationRecord` is a new superclass for all app models, analogous to app
+controllers subclassing `ApplicationController` instead of
+`ActionController::Base`. This gives apps a single spot to configure app-wide
+model behavior.
-In Rails 5.0, returning `false` in a callback will not have this side effect
-of halting the callback chain. Instead, callback chains must be explicitly
-halted by calling `throw(:abort)`.
+When upgrading from Rails 4.2 to Rails 5.0 you need to create an
+`application_record.rb` file in `app/models/` and add the following content:
-When you upgrade from Rails 4.2 to Rails 5.0, returning `false` in a callback
-will still halt the callback chain, but you will receive a deprecation warning
-about this upcoming change.
+```
+class ApplicationRecord < ActiveRecord::Base
+ self.abstract_class = true
+end
+```
+
+### Halting callback chains via `throw(:abort)`
+
+In Rails 4.2, when a 'before' callback returns `false` in Active Record
+and Active Model, then the entire callback chain is halted. In other words,
+successive 'before' callbacks are not executed, and neither is the action wrapped
+in callbacks.
+
+In Rails 5.0, returning `false` in an Active Record or Active Model callback
+will not have this side effect of halting the callback chain. Instead, callback
+chains must be explicitly halted by calling `throw(:abort)`.
+
+When you upgrade from Rails 4.2 to Rails 5.0, returning `false` in those kind of
+callbacks will still halt the callback chain, but you will receive a deprecation
+warning about this upcoming change.
When you are ready, you can opt into the new behavior and remove the deprecation
warning by adding the following configuration to your `config/application.rb`:
- config.active_support.halt_callback_chains_on_return_false = false
+ ActiveSupport.halt_callback_chains_on_return_false = false
+
+Note that this option will not affect Active Support callbacks since they never
+halted the chain when any value was returned.
See [#17227](https://github.com/rails/rails/pull/17227) for more details.
+### ActiveJob jobs now inherit from ApplicationJob by default
+
+In Rails 4.2 an ActiveJob inherits from `ActiveJob::Base`. In Rails 5.0 this
+behavior has changed to now inherit from `ApplicationJob`.
+
+When upgrading from Rails 4.2 to Rails 5.0 you need to create an
+`application_job.rb` file in `app/jobs/` and add the following content:
+
+```
+class ApplicationJob < ActiveJob::Base
+end
+```
+
+Then make sure that all your job classes inherit from it.
+
+See [#19034](https://github.com/rails/rails/pull/19034) for more details.
+
Upgrading from Rails 4.1 to Rails 4.2
-------------------------------------
@@ -125,7 +184,7 @@ the logs. In the next version, these errors will no longer be suppressed.
Instead, the errors will propagate normally just like in other Active
Record callbacks.
-When you define a `after_rollback` or `after_commit` callback, you
+When you define an `after_rollback` or `after_commit` callback, you
will receive a deprecation warning about this upcoming change. When
you are ready, you can opt into the new behavior and remove the
deprecation warning by adding following configuration to your
@@ -281,7 +340,7 @@ end
The migration DSL has been expanded to support foreign key definitions. If
you've been using the Foreigner gem, you might want to consider removing it.
Note that the foreign key support of Rails is a subset of Foreigner. This means
-that not every Foreigner definition can be fully replaced by it's Rails
+that not every Foreigner definition can be fully replaced by its Rails
migration DSL counterpart.
The migration procedure is as follows:
@@ -297,11 +356,11 @@ Upgrading from Rails 4.0 to Rails 4.1
### CSRF protection from remote `<script>` tags
-Or, "whaaat my tests are failing!!!?"
+Or, "whaaat my tests are failing!!!?" or "my `<script>` widget is busted!!"
Cross-site request forgery (CSRF) protection now covers GET requests with
-JavaScript responses, too. This prevents a third-party site from referencing
-your JavaScript URL and attempting to run it to extract sensitive data.
+JavaScript responses, too. This prevents a third-party site from remotely
+referencing your JavaScript with a `<script>` tag to extract sensitive data.
This means that your functional and integration tests that use
@@ -317,8 +376,9 @@ xhr :get, :index, format: :js
to explicitly test an `XmlHttpRequest`.
-If you really mean to load JavaScript from remote `<script>` tags, skip CSRF
-protection on that action.
+Note: Your own `<script>` tags are treated as cross-origin and blocked by
+default, too. If you really mean to load JavaScript from `<script>` tags,
+you must now explicitly skip CSRF protection on those actions.
### Spring
@@ -443,7 +503,7 @@ If your application currently depend on MultiJSON directly, you have a few optio
WARNING: Do not simply replace `MultiJson.dump` and `MultiJson.load` with
`JSON.dump` and `JSON.load`. These JSON gem APIs are meant for serializing and
-deserializing arbitrary Ruby objects and are generally [unsafe](http://www.ruby-doc.org/stdlib-2.0.0/libdoc/json/rdoc/JSON.html#method-i-load).
+deserializing arbitrary Ruby objects and are generally [unsafe](http://www.ruby-doc.org/stdlib-2.2.2/libdoc/json/rdoc/JSON.html#method-i-load).
#### JSON gem compatibility
@@ -866,6 +926,20 @@ this gem such as `whitelist_attributes` or `mass_assignment_sanitizer` options.
* To re-enable the old finders, you can use the [activerecord-deprecated_finders gem](https://github.com/rails/activerecord-deprecated_finders).
+* Rails 4.0 has changed to default join table for `has_and_belongs_to_many` relations to strip the common prefix off the second table name. Any existing `has_and_belongs_to_many` relationship between models with a common prefix must be specified with the `join_table` option. For example:
+
+```ruby
+CatalogCategory < ActiveRecord::Base
+ has_and_belongs_to_many :catalog_products, join_table: 'catalog_categories_catalog_products'
+end
+
+CatalogProduct < ActiveRecord::Base
+ has_and_belongs_to_many :catalog_categories, join_table: 'catalog_categories_catalog_products'
+end
+```
+
+* Note that the prefix takes scopes into account as well, so relations between `Catalog::Category` and `Catalog::Product` or `Catalog::Category` and `CatalogProduct` need to be updated similarly.
+
### Active Resource
Rails 4.0 extracted Active Resource to its own gem. If you still need the feature you can add the [Active Resource gem](https://github.com/rails/activeresource) in your Gemfile.
@@ -895,7 +969,7 @@ Rails 4.0 extracted Active Resource to its own gem. If you still need the featur
Please note that you should wait to set `secret_key_base` until you have 100% of your userbase on Rails 4.x and are reasonably sure you will not need to rollback to Rails 3.x. This is because cookies signed based on the new `secret_key_base` in Rails 4.x are not backwards compatible with Rails 3.x. You are free to leave your existing `secret_token` in place, not set the new `secret_key_base`, and ignore the deprecation warnings until you are reasonably sure that your upgrade is otherwise complete.
-If you are relying on the ability for external applications or Javascript to be able to read your Rails app's signed session cookies (or signed cookies in general) you should not set `secret_key_base` until you have decoupled these concerns.
+If you are relying on the ability for external applications or JavaScript to be able to read your Rails app's signed session cookies (or signed cookies in general) you should not set `secret_key_base` until you have decoupled these concerns.
* Rails 4.0 encrypts the contents of cookie-based sessions if `secret_key_base` has been set. Rails 3.x signed, but did not encrypt, the contents of cookie-based session. Signed cookies are "secure" in that they are verified to have been generated by your app and are tamper-proof. However, the contents can be viewed by end users, and encrypting the contents eliminates this caveat/concern without a significant performance penalty.
@@ -909,6 +983,8 @@ Please read [Pull Request #9978](https://github.com/rails/rails/pull/9978) for d
* Rails 4.0 has removed the XML parameters parser. You will need to add the `actionpack-xml_parser` gem if you require this feature.
+* Rails 4.0 changes the default `layout` lookup set using symbols or procs that return nil. To get the "no layout" behavior, return false instead of nil.
+
* Rails 4.0 changes the default memcached client from `memcache-client` to `dalli`. To upgrade, simply add `gem 'dalli'` to your `Gemfile`.
* Rails 4.0 deprecates the `dom_id` and `dom_class` methods in controllers (they are fine in views). You will need to include the `ActionView::RecordIdentifier` module in controllers requiring this feature.
@@ -1053,7 +1129,7 @@ config.active_record.auto_explain_threshold_in_seconds = 0.5
### config/environments/test.rb
-The `mass_assignment_sanitizer` configuration setting should also be be added to `config/environments/test.rb`:
+The `mass_assignment_sanitizer` configuration setting should also be added to `config/environments/test.rb`:
```ruby
# Raise exception on mass assignment protection for Active Record models
@@ -1154,8 +1230,10 @@ You can help test performance with these additions to your test environment:
```ruby
# Configure static asset server for tests with Cache-Control for performance
-config.serve_static_files = true
-config.static_cache_control = 'public, max-age=3600'
+config.public_file_server.enabled = true
+config.public_file_server.headers = {
+ 'Cache-Control' => 'public, max-age=3600'
+}
```
### config/initializers/wrap_parameters.rb