Phoenix LiveView

Phoenix LiveView enables rich, real-time user experiences with server-rendered HTML. For more information, see the initial announcement.

Note: Currently LiveView is under active development and we are focused on getting a stable and solid initial version out. For this reason, we will be accepting only bug reports in the issues tracker for now. We will open the issues tracker for features after the current milestone is ironed out.

Learning

As official guides are being developed, see our existing comprehensive docs and examples to get up to speed:

• Phoenix.LiveView docs for general usage
• phoenix_live_view.js docs
• Phoenix.LiveViewTest for testing docs
• LiveView example repo with a handful of examples from Weather widgets, autocomplete search, and games like Snake or Pacman

Installation

Currently LiveView is only available from GitHub. To use it, add to your mix.exs:

def deps do
  [
    {:phoenix_live_view, github: "phoenixframework/phoenix_live_view"}
  ]
end

Once installed, update your endpoint's configuration to include a signing salt. You can generate a signing salt by running mix phx.gen.secret 32.

config :my_app, MyAppWeb.Endpoint,
   live_view: [
     signing_salt: "SECRET_SALT"
   ]

Update your configuration to enable writing LiveView templates with the .leex extension.

config :phoenix,
  template_engines: [leex: Phoenix.LiveView.Engine]

Next, add the LiveView flash plug to your browser pipeline, after :fetch_flash:

pipeline :browser do
  ...
  plug :fetch_flash
  plug Phoenix.LiveView.Flash
end

Then add the following imports to your web file in lib/my_app_web.ex:

def view do
  quote do
    ...
    import Phoenix.LiveView, only: [live_render: 2, live_render: 3]
  end
end

def router do
  quote do
    ...
    import Phoenix.LiveView.Router
  end
end

Next, expose a new socket for LiveView updates in your app's endpoint module.

defmodule MyAppWeb.Endpoint do
  use Phoenix.Endpoint

  socket "/live", Phoenix.LiveView.Socket

  # ...
end

Add LiveView NPM dependencies in your package.json.

{
  "dependencies": {
    "phoenix": "file:../deps/phoenix",
    "phoenix_html": "file:../deps/phoenix_html",
    "phoenix_live_view": "file:../deps/phoenix_live_view"
  }
}

Then install the new npm dependency.

npm install --prefix assets

Enable connecting to a LiveView socket in your app.js file.

import LiveSocket from "phoenix_live_view"

let liveSocket = new LiveSocket("/live")
liveSocket.connect()

Finally, by convention live views are saved in a lib/my_app_web/live/ directory. For live page reload support, add the following pattern to your config/dev.exs:

config :demo, MyAppWeb.Endpoint,
  live_reload: [
    patterns: [
      ...,
      ~r{lib/my_app_web/live/.*(ex)$}
    ]
  ]

You can also optionally import the style for the default CSS classes in your app.css file.

@import "../../deps/phoenix_live_view/assets/css/live_view.css";