First, bump your phoenix in mix.exs:

def deps do
  [{:phoenix, "~> 0.14"}, ...
end

phoenix_html

Update your phoenix_html version to 1.1.0 in mix.exs:

def deps do
  [{:phoenix, "~> 0.14"},
  {:phoenix_html, "~> 1.1"}, ...
end

then run $ mix deps.get

1.1 raises on missing assigns in your templates. If you had cases where you were using assigns that may or may not have been set, update your code as so:

0.13.x

<%= if @message do %>

0.14.0

<%= if assigns[:message] do %>

Controller

plug :action is now called automatically as the last plug in your controller. Simply remove it, ie:

0.13.x:

defmodule App.Controller do
  use App.Web, :controller
  
  plug :authenticate
  plug :action
  
  def show(conn, params) do
    ...
  end
end

0.14.0:

defmodule App.Controller do
  use App.Web, :controller
  
  plug :authenticate
  
  def show(conn, params) do
    ...
  end
end

View

The default template web/templates/layout/application.html.eex has been renamed to app.html.eex. Simply rename this file:

$ mv web/templates/layout/application.html.eex web/templates/layout/app.html.eex

Endpoint

The :format option in :render_errors has been renamed to :default_format. Update your config/*.exs accordingly.

Phoenix.PubSub.Redis

The Redis PubSub adapter has been extracted into its own project. If using redis, see the project's readme for installation and configuration instructions

Javascript client

Upgarde to the latest phoenix.js client by replacing web/static/vendor/phoenix.js with the latest version: https://raw.githubusercontent.com/phoenixframework/phoenix/6da5a66a11ff02e5629e3512649413afe9257bc7/priv/static/phoenix.js

Socket params can now be added to apply default, overridable params to all channel params, ie

let socket = new Phoenix.Socket("/ws", {params: {userToken: theToken}})

Logging has been enhanced. To enable logging, or add customized logging of events, add a callback to the socket options, ie:

let socket = new Phoenix.Socket("/ws", {
  logger: (kind, msg, data) => { console.log(${kind}: ${msg}, data) }
})