Hi All,

Today, we are going to explore how Phoenix works. Let's start with the basics.

What is Elixir and the Phoenix web framework?

Elixir is a functional, dynamically typed language built on top of Erlang. It was developed by José Valim, a former member of the Ruby on Rails team, to address performance issues in both Ruby on Rails and Erlang. The language's syntax is similar to that of Ruby on Rails.

Elixir is utilized to create exceptionally scalable, fault-tolerant, and maintainable applications. Its key features include the following:

• Compiling code into bytecode for the Erlang VM
• Emphasizing higher-order functions and recursion
• Providing powerful pattern matching
• Being dynamically typed, performing type checks at runtime

Benefits of Elixir

Elixir, running on the Erlang VM (BEAM), possesses several important features for creating excellent apps:

• Concurrency: Elixir employs isolated, CPU-based process threads that communicate via messages.
• Scalability: Lightweight threads facilitate easy scaling with minimal processes.
• Reliability: Elixir's supervisor system promptly restarts failed processes, reducing downtime.

When it comes to web applications, the Phoenix framework makes it easier to create fundamental functionalities.

Introduction to Phoenix

Phoenix is a web framework in the Elixir ecosystem designed for building scalable and fault-tolerant applications. It follows the MVC (Model-View-Controller) pattern, similar to frameworks like Ruby on Rails and Django.

One of the standout features of Phoenix is LiveView, a library that allows you to build real-time applications without the need for client-side JavaScript. LiveView calculates page changes and pushes updates through WebSockets.

How Phoenix works

Plugs are essential components of Phoenix, providing a way to compose web applications with functions. Phoenix converts incoming requests into a Conn data structure, managing HTTP requests and responses.

Image credit: Logrocket

The Conn structure is passed through multiple plugs to complete the functionality and return a response:

1. Receive a request.
2. Convert it to Conn.
3. Pass through several plugs.
4. Return a response.

Lifecycle of Phoenix requests

In Phoenix, an incoming request goes through several plugs to return the required response:

Image credit: Logrocket

1. The endpoint receives the request and converts it into a Conn data structure.
2. The Conn is forwarded to the router.
3. The router pipelines the Conn to the controller.
4. The controller interacts with the model to fetch data and render it using HTML or JSON templates.

The endpoint, router, and controllers are all plugs. Everything in Phoenix is a composable function that transforms data into different structures.

That's it for the day. In the next part, we will go through mix tasks that are very helpful for the development of applications using the Phoenix framework.

If you have any suggestions/doubts, feel free to reach out to me via one of the following methods.

LinkedIn: https://www.linkedin.com/in/rushikesh-pandit-646834100/
GitHub: https://github.com/rushikeshpandit
Portfolio: https://www.rushikeshpandit.in