Bruce Tate - Programming Phoenix LiveView: Interactive Elixir Web Programming Without Writing Any JavaScript

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The book youre reading is in beta. This means that we update itfrequently. Here is the list of the major changes that have been madeat each beta release of the book, with the most recent change first.

• Addressed errata.

• Updated code to use recent versions of LiveView and Phoenix.

• Updated relevant chapters to reflect changes in these recent versions.

• Updated chapters to use new HEEx templates instead of EEx.

• Renamed Stateless Components chapter to Chapter 6, and updated chapter with the new function component syntax and usage.

• Renamed Stateful Components chapter to Chapter 7, and updated chapter with the new live component syntax and usage.

• Removed content on the Surface library in favor of leveraging new built-in function and live components along with HEEx HTML validation.

• Updated Forms chapter and other relevant sections to use the new built-in form function component.

• Added Chapter 13, .

• Addressed errata.

• Added Chapter 12, .

• Addressed errata.

• Added Chapter 11, .

• Addressed errata.

• Added Chapter 10, .

• Addressed errata.

• Added Chapter 9, .

• Addressed errata.

• Initial beta release.

If you havent been following closely, it might seem like LiveView came suddenly, like a new seedling that breaks through the soil surface overnight. That narrative lacks a few important details, like all of the slow germination and growth that happens out of sight.

Chris McCord, the creator of Phoenix, worked on Ruby on Rails before coming over to the Elixir community. More and more often, his consultancy was asked to use Ruby on Rails to build dynamic single-page apps (SPAs). He tried to build a server-side framework on top of the Ruby on Rails infrastructure, much like LiveView, that would allow him to meet these demands for interactivity. But Chris recognized that the Ruby infrastructure was not robust enough to support his idea. He needed better reliability, higher throughput, and more even performance. He shopped around for a more appropriate language and infrastructure, and found Elixir.

When Chris moved from Ruby to Elixir, he first learned the metaprogramming techniques hed need to implement his vision. Then, he began building the Phoenix web development framework to support the infrastructure hed need to make this vision a reality.

At that time, Jos Valim began helping Chris write idiomatic Elixir abstractions relying on OTP. OTP libraries have powered many of the worlds phone switches, offering stunning uptime statistics and near realtime performance, so it played a critical role in Phoenix. Chris introduced a programming model to Phoenix called channels . This service uses HTTP WebSockets and OTP to simplify interactions in Phoenix. As the Phoenix team fleshed out the programming model, they saw stunning performance and reliability numbers. Because of OTP, Phoenix would support the concurrency, reliability, and performance that interactive applications demand .

In functional programming, Chris found cleaner ways to tie his ideas together than object orientation offered. He learned to compose functions with Elixir pipelines and the plugs. His work with OTP taught him to think in the same composable steps well show you as this book unfolds. His work with metaprogramming and macros prepared him to build smooth features beyond what basic Elixir provided. As a result, in Phoenix LiveView, users would find a pleasant, productive programming experience .

As the web programming field around him grew, frameworks like React and languages like Elm provided a new way to think about user interface development in layers. Chris took note. Some frameworks like Morphdom popped up to allow seamless replacement of page elements in a customizable way. The Phoenix team was able to build JavaScript features into LiveView that automate the process of changing a user interface on a socket connection. In LiveView, programmers would find a beautiful programming model based on tested concepts , and one that provided JavaScript infrastructure so developers didnt need to write their own JavaScript.