Ruby on Rails 5.1 Release Notes

Highlights in Rails 5.1:

Yarn Support
Optional Webpack support
jQuery no longer a default dependency
System tests
Encrypted secrets
Parameterized mailers
Direct & resolved routes
Unification of form_for and form_tag into form_with

These release notes cover only the major changes. To learn about various bug fixes and changes, please refer to the change logs or check out the list of commits in the main Rails repository on GitHub.

Upgrading to Rails 5.1

ToDo

Major Features

Yarn Support

Pull Request

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

Optional Webpack support

Pull Request

Rails apps can integrate with Webpack, a JavaScript asset bundler, more easily using the new Webpacker gem. Use the --webpack flag when generating new applications to enable Webpack integration.

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

jQuery no longer a default dependency

Pull Request

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

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

System tests

Pull Request

Rails 5.1 has baked-in support for writing Capybara tests, in the form of System tests. You need no longer worry about configuring Capybara and database cleaning strategies for such tests. Rails 5.1 provides a wrapper for running tests in Chrome with additional features such as failure screenshots.

Encrypted secrets

Pull Request

Rails will now allow management of application secrets in a secure way, building on top of the sekrets gem.

Run bin/rails secrets:setup to setup a new encrypted secrets file. This will also generate a master key, which must be stored outside of the repository. The secrets 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 the RAILS_MASTER_KEY environment variable, or in a key file.

Parameterized mailers

Pull Request

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

class InvitationsMailer < ApplicationMailer

  before_action { @inviter, @invitee = params[:inviter], params[:invitee] }
  before_action { @account = params[:inviter].account }

  def account_invitation
    mail subject: "#{@inviter.name} invited you to their Basecamp (#{@account.name})"
  end

  def project_invitation
    @project    = params[:project]
    @summarizer = ProjectInvitationSummarizer.new(@project.bucket)

    mail subject: "#{@inviter.name.familiar} added you to a project in Basecamp (#{@account.name})"
  end
end

InvitationsMailer.with(inviter: person_a, invitee: person_b).account_invitation.deliver_later

Direct & resolved routes

Pull Request

Rails 5.1 has added two new methods, resolve and direct, to the routing DSL.

The resolve method allows customizing polymorphic mapping of models.

resource :basket

resolve("Basket") { [:basket] }

<%= form_for @basket do |form| %>
  <!-- basket form -->
<% end %>

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

The direct method allows creation of custom URL helpers.

direct(:homepage) { "http://www.rubyonrails.org" }

>> homepage_url
=> "http://www.rubyonrails.org"

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

direct :commentable do |model|
  [ model, anchor: model.dom_id ]
end

direct :main do
  { controller: 'pages', action: 'index', subdomain: 'www' }
end

Unification of form_for and form_tag into form_with

Pull Request

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, and can generate form tags based on URLs, scopes or models.

# Using just a URL:

<%= form_with url: posts_path do |form| %>
  <%= form.text_field :title %>
<% end %>

# =>
<form action="/posts" method="post" data-remote="true">
  <input type="text" name="title">
</form>

# Adding a scope prefixes the input field names:

<%= form_with scope: :post, url: posts_path do |form| %>
  <%= form.text_field :title %>
<% end %>
# =>
<form action="/posts" method="post" data-remote="true">
  <input type="text" name="post[title]">
</form>

# Using a model infers both the URL and scope:

<%= form_with model: Post.new do |form| %>
  <%= form.text_field :title %>
<% end %>
# =>
<form action="/posts" method="post" data-remote="true">
  <input type="text" name="post[title]">
</form>

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

<%= form_with model: Post.first do |form| %>
  <%= form.text_field :title %>
<% end %>
# =>
<form action="/posts/1" method="post" data-remote="true">
  <input type="hidden" name="_method" value="patch">
  <input type="text" name="post[title]" value="<the title of the post>">
</form>