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Diffstat (limited to 'guides/source/upgrading_ruby_on_rails.md')
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1 files changed, 253 insertions, 18 deletions
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md index 8aae3bbc1a..cc20782780 100644 --- a/guides/source/upgrading_ruby_on_rails.md +++ b/guides/source/upgrading_ruby_on_rails.md @@ -3,6 +3,8 @@ A Guide for Upgrading Ruby on Rails This guide provides steps to be followed when you upgrade your applications to a newer version of Ruby on Rails. These steps are also available in individual release guides. +-------------------------------------------------------------------------------- + General Advice -------------- @@ -22,11 +24,76 @@ Rails generally stays close to the latest released Ruby version when it's releas 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. -Upgrading from Rails 4.0 to Rails 4.1 +### The Rake Task + +Rails provides the `rails:update` rake task. After updating the Rails version +in the Gemfile, run this rake task. +This will help you with the creation of new files and changes of old files in a +interactive session. + +```bash +$ rake rails:update + identical config/boot.rb + exist config + conflict config/routes.rb +Overwrite /myapp/config/routes.rb? (enter "h" for help) [Ynaqdh] + force config/routes.rb + conflict config/application.rb +Overwrite /myapp/config/application.rb? (enter "h" for help) [Ynaqdh] + force config/application.rb + conflict config/environment.rb +... +``` + +Don't forget to review the difference, to see if there were any unexpected changes. + +Upgrading from Rails 4.1 to Rails 4.2 ------------------------------------- NOTE: This section is a work in progress. +### Serialized attributes + +When using a custom coder (e.g. `serialize :metadata, JSON`), +assigning `nil` to a serialized attribute will save it to the database +as `NULL` instead of passing the `nil` value through the coder (e.g. `"null"` +when using the `JSON` coder). + +### `after_bundle` in Rails templates + +If you have a Rails template that adds all the files in version control, it +fails to add the generated binstubs because it gets executed before Bundler: + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +git :init +git add: "." +git commit: %Q{ -m 'Initial commit' } +``` + +You can now wrap the `git` calls in an `after_bundle` block. It will be run +after the binstubs have been generated. + +```ruby +# template.rb +generate(:scaffold, "person name:string") +route "root to: 'people#index'" +rake("db:migrate") + +after_bundle do + git :init + git add: "." + git commit: %Q{ -m 'Initial commit' } +end +``` + +Upgrading from Rails 4.0 to Rails 4.1 +------------------------------------- + ### CSRF protection from remote `<script>` tags Or, "whaaat my tests are failing!!!?" @@ -79,11 +146,14 @@ secrets, you need to: secret_key_base: production: - secret_key_base: + secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> ``` -2. Copy the existing `secret_key_base` from the `secret_token.rb` initializer to - `secrets.yml` under the `production` section. +2. Use your existing `secret_key_base` from the `secret_token.rb` initializer to + set the SECRET_KEY_BASE environment variable for whichever users run the Rails + app in production mode. Alternately, you can simply copy the existing + `secret_key_base` from the `secret_token.rb` initializer to `secrets.yml` + under the `production` section, replacing '<%= ENV["SECRET_KEY_BASE"] %>'. 3. Remove the `secret_token.rb` initializer. @@ -104,13 +174,57 @@ Applications created before Rails 4.1 uses `Marshal` to serialize cookie values the signed and encrypted cookie jars. If you want to use the new `JSON`-based format in your application, you can add an initializer file with the following content: - ```ruby - Rails.application.config.cookies_serializer :hybrid - ``` +```ruby +Rails.application.config.action_dispatch.cookies_serializer = :hybrid +``` This would transparently migrate your existing `Marshal`-serialized cookies into the new `JSON`-based format. +When using the `:json` or `:hybrid` serializer, you should beware that not all +Ruby objects can be serialized as JSON. For example, `Date` and `Time` objects +will be serialized as strings, and `Hash`es will have their keys stringified. + +```ruby +class CookiesController < ApplicationController + def set_cookie + cookies.encrypted[:expiration_date] = Date.tomorrow # => Thu, 20 Mar 2014 + redirect_to action: 'read_cookie' + end + + def read_cookie + cookies.encrypted[:expiration_date] # => "2014-03-20" + end +end +``` + +It's advisable that you only store simple data (strings and numbers) in cookies. +If you have to store complex objects, you would need to handle the conversion +manually when reading the values on subsequent requests. + +If you use the cookie session store, this would apply to the `session` and +`flash` hash as well. + +### Flash structure changes + +Flash message keys are +[normalized to strings](https://github.com/rails/rails/commit/a668beffd64106a1e1fedb71cc25eaaa11baf0c1). They +can still be accessed using either symbols or strings. Looping through the flash +will always yield string keys: + +```ruby +flash["string"] = "a string" +flash[:symbol] = "a symbol" + +# Rails < 4.1 +flash.keys # => ["string", :symbol] + +# Rails >= 4.1 +flash.keys # => ["string", "symbol"] +``` + +Make sure you are comparing Flash message keys against strings. + ### Changes in JSON handling There are a few major changes related to JSON handling in Rails 4.1. @@ -165,6 +279,16 @@ If your application depends on one of these features, you can get them back by adding the [`activesupport-json_encoder`](https://github.com/rails/activesupport-json_encoder) gem to your Gemfile. +#### JSON representation of Time objects + +`#as_json` for objects with time component (`Time`, `DateTime`, `ActiveSupport::TimeWithZone`) +now returns millisecond precision by default. If you need to keep old behavior with no millisecond +precision, set the following in an initializer: + +``` +ActiveSupport::JSON::Encoding.time_precision = 0 +``` + ### Usage of `return` within inline callback blocks Previously, Rails allowed inline callback blocks to use `return` this way: @@ -262,6 +386,114 @@ authors = Author.where(name: 'Hank Moody').to_a authors.compact! ``` +### Changes on Default Scopes + +Default scopes are no longer overridden by chained conditions. + +In previous versions 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. + +Before: + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' + +User.where(state: 'inactive') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'inactive' +``` + +After: + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { where state: 'active' } + scope :inactive, -> { where state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'active' + +User.where(state: 'inactive') +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' AND "users"."state" = 'inactive' +``` + +To get the previous behavior it is needed to explicitly remove the +`default_scope` condition using `unscoped`, `unscope`, `rewhere` or +`except`. + +```ruby +class User < ActiveRecord::Base + default_scope { where state: 'pending' } + scope :active, -> { unscope(where: :state).where(state: 'active') } + scope :inactive, -> { rewhere state: 'inactive' } +end + +User.all +# SELECT "users".* FROM "users" WHERE "users"."state" = 'pending' + +User.active +# SELECT "users".* FROM "users" WHERE "users"."state" = 'active' + +User.inactive +# SELECT "users".* FROM "users" WHERE "users"."state" = 'inactive' +``` + +### Rendering content from string + +Rails 4.1 introduces `:plain`, `:html`, and `:body` options to `render`. Those +options are now the preferred way to render string-based content, as it allows +you to specify which content type you want the response sent as. + +* `render :plain` will set the content type to `text/plain` +* `render :html` will set the content type to `text/html` +* `render :body` will *not* set the content type header. + +From the security standpoint, if you don't expect to have any markup in your +response body, you should be using `render :plain` as most browsers will escape +unsafe content in the response for you. + +We will be deprecating the use of `render :text` in a future version. So please +start using the more precise `:plain:`, `:html`, and `:body` options instead. +Using `render :text` may pose a security risk, as the content is sent as +`text/html`. + +### PostgreSQL json and hstore datatypes + +Rails 4.1 will map `json` and `hstore` columns to a string-keyed Ruby `Hash`. +In earlier versions a `HashWithIndifferentAccess` was used. This means that +symbol access is no longer supported. This is also the case for +`store_accessors` based on top of `json` or `hstore` columns. Make sure to use +string keys consistently. + +### Explicit block use for `ActiveSupport::Callbacks` + +Rails 4.1 now expects an explicit block to be passed when calling +`ActiveSupport::Callbacks.set_callback`. This change stems from +`ActiveSupport::Callbacks` being largely rewritten for the 4.1 release. + +```ruby +# Previously in Rails 4.0 +set_callback :save, :around, ->(r, &block) { stuff; result = block.call; stuff } + +# Now in Rails 4.1 +set_callback :save, :around, ->(r, block) { stuff; result = block.call; stuff } +``` + Upgrading from Rails 3.2 to Rails 4.0 ------------------------------------- @@ -333,7 +565,7 @@ being used, you can update your form to use the `PUT` method instead: <%= form_for [ :update_name, @user ], method: :put do |f| %> ``` -For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/26/edge-rails-patch-is-the-new-primary-http-method-for-updates/) +For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/25/edge-rails-patch-is-the-new-primary-http-method-for-updates/) on the Rails blog. #### A note about media types @@ -349,7 +581,7 @@ def update respond_to do |format| format.json do # perform a partial update - @post.update params[:post] + @article.update params[:article] end format.json_patch do @@ -393,6 +625,9 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep * Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. You shouldn't use instance methods since it's now deprecated. You should change them to use class methods, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`. +* When using the default coder, assigning `nil` to a serialized attribute will save it +to the database as `NULL` instead of passing the `nil` value through YAML (`"--- \n...\n"`). + * Rails 4.0 has removed `attr_accessible` and `attr_protected` feature in favor of Strong Parameters. You can use the [Protected Attributes gem](https://github.com/rails/protected_attributes) for a smooth upgrade path. * If you are not using Protected Attributes, you can remove any options related to @@ -567,9 +802,8 @@ Active Record Observer and Action Controller Sweeper have been extracted to the ### sprockets-rails -* `assets:precompile:primary` has been removed. Use `assets:precompile` instead. -* The `config.assets.compress` option should be changed to -`config.assets.js_compressor` like so for instance: +* `assets:precompile:primary` and `assets:precompile:all` have been removed. Use `assets:precompile` instead. +* The `config.assets.compress` option should be changed to `config.assets.js_compressor` like so for instance: ```ruby config.assets.js_compressor = :uglifier @@ -577,22 +811,23 @@ config.assets.js_compressor = :uglifier ### sass-rails -* `asset-url` with two arguments is deprecated. For example: `asset-url("rails.png", image)` becomes `asset-url("rails.png")` +* `asset-url` with two arguments is deprecated. For example: `asset-url("rails.png", image)` becomes `asset-url("rails.png")`. Upgrading from Rails 3.1 to Rails 3.2 ------------------------------------- -If your application is currently on any version of Rails older than 3.1.x, you should upgrade to Rails 3.1 before attempting an update to Rails 3.2. +If your application is currently on any version of Rails older than 3.1.x, you +should upgrade to Rails 3.1 before attempting an update to Rails 3.2. -The following changes are meant for upgrading your application to Rails 3.2.16, -the last 3.2.x version of Rails. +The following changes are meant for upgrading your application to the latest +3.2.x version of Rails. ### Gemfile Make the following changes to your `Gemfile`. ```ruby -gem 'rails', '3.2.16' +gem 'rails', '3.2.18' group :assets do gem 'sass-rails', '~> 3.2.6' @@ -753,7 +988,7 @@ AppName::Application.config.session_store :cookie_store, key: 'SOMETHINGNEW' or ```bash -$ rake db:sessions:clear +$ bin/rake db:sessions:clear ``` ### Remove :cache and :concat options in asset helpers references in views |