Develop multi-platform apps using Ruby on Rails and Hotwire.

We’ll be building a marketplace app called Piazza in this book. We’ll set up the Rails, iOS and Android apps for it. We’ll also push them to GitHub and configure hosting on Render.com.

A whistle-stop tour of Turbo, Turbo Native, and Stimulus. We’ll cover what they are and how to use them. Strada will be added when it’s released.

We’ll lay the foundation of Piazza by creating Users and Organizations. Along with the models, we’ll build views and controllers to allow users to sign up.

Following on from the sign up flow, we’ll build an authentication system from scratch to securely identify the user behind every request. We’ll also build the navigation backbone of the app.

System tests allow us to simulate the actions of a user. We’ll cover the functionality build so far with system tests. Additionally, we’ll explore the use of Turbo Frames and how to debug Rails apps.

We’ll bring the functionality so far to the native apps. This involves laying the substructure around Turbo Native. We’ll build a tabbed interface on both iOS and Android and look at how Turbo Native works under the hood.

Using Strada, we can build native components powered by the web app. We’ll explore how Strada works and use it to build a fully native toolbar menu in the iOS and Android apps.

Action Mailer makes it easy to send emails from a Rails app. We’ll use SendGrid as the production SMTP server and build a system allowing users to reset their password via email.

We’ll build Piazza’s core functionality to list ads on the platform. In this process, we’ll cover several advanced features in Rails such as nested forms, polymorphic associations, and database arrays. Pagination will be covered for the home feed. In the native apps, we’ll build a Turbo Frame powered infinite scrolling feed.

Building on top of the functionality in the previous chapter, we’ll enable file uploads and rich text descriptions in an ad. These will be powered by Active Storage and Action Text. We’ll also take a peek under the hood of both these frameworks.

Breadcrumbs make navigation easier in web apps. We’ll build a simple mechanism for this from scratch. We’ll also allow the user to create draft ads and save ads to view later.

Authorization complements authentication to determine which actions a user is allowed to perform. We’ll build a simple system for this. We’ll also replace the boring default error pages with snazzier ones rendered from within the Rails stack.

Rails has a built-in interface for background jobs called Active Job. We’ll use Sidekiq as the executor and build a job to expire an ad 30 days after it’s published. We’ll also use a plugin called Sidekiq Cron to clear unattached Active Storage blobs at regular intervals.

PostgreSQL’s full-text search packs in one hell of a punch. We’ll explore how it works, how to create the relevant indexes, and how to construct search SQL queries using Arel.

We’ll build the mechanism for a buyer to contact a seller in Piazza. For real-time message delivery, we’ll use Action Cable. Other topics covered include Turbo Frame powered modals, custom Turbo Stream actions, and Action View request variants.

Using Kredis, we’ll detect whether a user is online when they receive a message. If they’re offline, we’ll send them an email notification to which they can reply. We’ll process the incoming reply using Action Mailbox.