Learn Elixir and Phoenix fast

Phoenix on Rails assumes no prior knowledge of Elixir. Part 1 will teach you all the Elixir you need to build a fully-featured Phoenix app. We’ll start with the three most important differences to understand between Ruby and Elixir. Then we’ll move through every important Elixir concept, relating it all to what you already know from Ruby.

Elixir and Ruby are more different than they first appear. The syntax is similar, but Elixir’s underlying design can be confusing to a Rubyist. Phoenix on Rails will get you familiar with the functional paradigm and everything it entails: recursion, pattern matching, the pipe operator and more. Even if you already know Elixir, you might still find Part 1 useful, as it will help you relate Elixir’s concepts to the Ruby you already know.

Elixir has many different types and data structures such as strings, lists, and maps. Some are easy to understand, like “atoms”, which are basically the same as Ruby’s “symbols”. Others are less familiar, like “tuples”, which have no direct analogy in Ruby. Phoenix on Rails will teach you how to use all of Elixir’s different types and data structures, explaining everything in terms that make maximum sense to a Ruby developer.

Now that you know Elixir, it’s time to learn some Phoenix! In Part 2 you’ll use Phoenix to build a simple app that’ll introduce you to all the major parts of the Phoenix stack. Some concepts will be familiar from Rails, like controllers, migrations and the router. Others will need more instruction - like components and contexts. We’ll cover them all.

In Rails you query and update your database using ActiveRecord models. In Phoenix, you do the same with Ecto - but Ecto’s approach is very different to ActiveRecord’s, and it’s one of the trickier things for a Rails developer to get used to. But don’t get discouraged - Phoenix on Rails will guide you gently through the four main parts of Ecto until you’re as comfortable with Ecto as you ever were in Rails.

Phoenix has changed a lot recently, and many existing tutorials are out of date. Phoenix on Rails teaches Phoenix 1.7 - but it doesn’t ignore Phoenix’s history, Where there have been major changes to Phoenix - such as when version 1.7 overhauled how “components” and “views” work - the course makes sure to educate you about what’s new and how things used to be. You’ll be thankful for this knowledge when you’re dealing with legacy code or struggling with old tutorials.

In Part 3 we’ll study some of Elixir’s more advanced features, starting with dependency management. In the Ruby ecosystem, you use bundler to manage your gems. Phoenix on Rails will introduce you to all the equivalent tooling from the Elixir world, such as Hex and Mix.

Other topics covered in part 3 include Erlang interoperability, and trickier Elixir keywords like use and with.

In Part 4 we’ll add new features to the CRUD app from part 2.

Advanced Rails developers will understand how Rails sits on top of Rack, a low-level Ruby tool for interfacing with web servers. The Phoenix equivalent is Plug, and everything you do in a Phoenix app is fundamentally about manipulating a “Plug.Conn” struct. There’s no handwaving in Phoenix on Rails - we take a close look at how Plug works and how it integrates with every part of your app.

Phoenix, like Rails, provides scaffolds - simple commands that let you generate huge amounts of working code. In Phoenix on Rails we make use of Phoenix’s scaffolds - but you don’t just run them and forget about them. Whenever a scaffold is used we take a close look at what was generated so that you understand exactly what it does. Studying the output of Phoenix scaffolds is a great way to learn about Phoenix’s intricacies and best practices.

LiveView is arguably Phoenix’s killer feature. With LiveView you don’t need Javascript to create a dynamic frontend - you can add interactive behaviour to your UI using Elixir alone. Phoenix on Rails will teach you everything you need to know about LiveView. Large parts of the two apps you build will use LiveView to render their UIs.

In Part 5, we’ll demystify Elixir’s often-overlooked typing system.

Elixir, like Ruby, is a dynamically-typed language - but that doesn’t mean we must lose all possible benefits of static typing. Instead, we document types using typespecs and validate them using Dialyzer and Dialyxir, enforcing types without compromising the expressiveness and flexibility of Elixir.

APIs are the backbone of modern web applications, and Phoenix provides a clean and efficient way to build them. In Part 6, we’ll update our Phoenix app to serve a RESTful API via JSON. By the end of this section, you’ll be adept at creating APIs that can serve any front-end application.

In Part 7 we’ll build a new, more advanced app from scratch. The first thing we’ll add is an authentication system so that users can log in. In Phoenix we don’t need any external dependencies like Rails’s Devise to create a fully-featured authentication system. Users will be able to register, sign in, recover their password and confirm their email address - and Phoenix’s generators let us add all of this with mere minutes of effort. We’ll thoroughly examine the generated code to understand exactly what we’ve created.

Once you’ve seen what’s possible with LiveView, you’ll believe what I believe - that Phoenix LiveView is the future of web development, We won’t shy away from LiveView in this course - it’s time to go deeper. We’ll see how to live validate a form, navigate between LiveViews with secure authentication, use a LiveView to upload files, and more.