Phoenix 1.4.0 Released

Posted on November 7th, 2018 by Chris McCord

Phoenix 1.4 is out! This release ships with exciting new features, most notably HTTP2 support, improved development experience with faster compile times, new error pages, and local SSL certificate generation. Additionally, our channel layer internals received an overhaul, providing better structure and extensibility. We also shipped a new and improved Presence javascript API, as well as Elixir formatter integration for our routing and testing DSLs.

phx_new hex archive

The mix archive can now be installed via hex, for a simpler, versioned installation experience.

To grab the new archive, simply run:

$ mix archive.uninstall phx_new
$ mix archive.install hex phx_new 1.4.0

The new generators now default to Ecto 3.0, which should be an easy upgrade for existing applications. Ecto 3.0 is packed with new features and improvements, which you can read more about in the Ecto 3.0 sneak peek post.

The new generators also use Milligram in favor of Bootstrap to support classless markup generation. The result is nice looking defaults that allow generated markup to be much more easily customized to your individual CSS requirements.

Note: Existing Phoenix applications will continue to work on Elixir 1.4, but the new archive requires Elixir 1.5+.


Thanks to the release of Cowboy 2, Phoenix 1.4 supports HTTP2 with a single line change to your mix.exs. Simply add {:plug_cowboy, "~> 2.0"} to your deps and Phoenix will run with the Cowboy 2 adapter.

Local SSL development

Most browsers require connections over SSL for HTTP2 requests, otherwise they fallback to HTTP 1.1 requests. To aid local development over SSL, phoenix includes a new phx.gen.cert task which generates a self-signed certificate for HTTPS testing in development.

See the phx.gen.cert docs for more information.

Faster Development Compilation

Our development compilation speeds have improved thanks to contributions to plug and compile-time changes. You can read more about the details in my DockYard Phoenix post

New Development 404 Page

Our 404 page in development now lists the available routes for the originating router, for example:

UserSocket connection info

A highly requested feature has been access to more underlying transport information when using Phoenix channels. The 1.4 release now provides a connect/3 UserSocket callback, which can provide connection information, such as the peer IP address, host information, and X-Headers of the HTTP request for WebSocket and Long-poll transports.

New Presence JavaScript API

A new, backwards compatible Presence JavaScript API has been introduced to both resolve race conditions as well as simplify the usage. Previously, multiple channel callbacks against "presence_state and "presence_diff" events were required on the client which dispatched to Presence.syncState and Presence.syncDiff functions. Now, the interface has been unified to a single onSync callback and the presence object tracks its own channel callbacks and state. For example:

let presence = new Presence(roomChannel)
presence.onSync(() => {
  console.log("users online:", presence.list((id, {name}) => name))

That’s all there is to it!


The mix generator now uses webpack for asset generation instead of brunch. The development experience remains the same – javascript goes in assets/js , css goes in assets/css , static assets live in assets/static , so those not interested in JS tooling nuances can continue the same patterns while using webpack. Those in need of optimal js tooling can benefit from webpack’s more sophisticated code bunding, with dead code elimination and more.

What’s Next

With the release of 1.4, we’re ready to focus on other exciting initiatives around the Elixir and Phoenix ecosystem. Most notably, we are excited to integrate telemetry into Phoenix for metric tracking and visualization. Simultaneously, we are also working to rewrite Phoenix.PubSub into smaller building blocks and provide a first-class distributed programming toolkit for the community. You can track this progress over at the Firenest project.

In addition to telemetry and firenest initiatives, we are also working on Phoenix.LiveView, to enable server-rendered real-time experiences without all the complexity of today’s single page application landscape. LiveView can enable rich UX on par with single-page apps in certain usecases and we can’t wait to get the initial release out to the community.

My ElixirConf keynote covers telemetry and LiveView in detail:

Programming Phoenix Book

The Programming Phoenix Book is in beta and available through PragProg, and includes all the latest changes for 1.4. We have titled the book “>= 1.4” and consider it relatively future proof as we continue minor version releases.

Special Thank You’s

I would like to specially thank Loïc Hoguin for his work on Cowboy 2, allowing us to provide a first-class HTTP2 experience. We would also like to thank Bram Verburg, who contributed the local SSL certificate generation, for cross-platform, dependency-free cert generation.

Additionally, I would like to thank José Valim and Plataformatec for their work on the channel layer overhaul which provides an extensible foundation going forward.

As always, we have provided step-by-step instructions for bringing your 1.3.x apps up to speed:

Please report issues to the issue tracker, and find us on #elixir-lang irc, elixir slack, and the Elixir forum if you have any questions. The full list of changes from the changelog can be found here.

Happy hacking!