Phoenix

Elixir Web Framework targeting full-featured, fault tolerant applications with realtime functionality

Build Status

Getting started

Requirements

Setup

  1. Install Phoenix 

     git clone https://github.com/phoenixframework/phoenix.git && cd phoenix && git checkout v0.3.0 && mix do deps.get, compile

  2. Create a new Phoenix application 

     mix phoenix.new your_app /path/to/scaffold/your_app

    Important: Run this task in the Phoenix installation directory cloned in the step above. The path provided: /path/to/scaffold/your_app/ should be outside of the framework installation directory. This will either create a new application directory or install the application into an existing directory.

    #### Examples: 

     mix phoenix.new your_app /Users/you/projects/my_app
 mix phoenix.new your_app ../relative_path/my_app

  3. Change directory to /path/to/scaffold/your_app. Install dependencies and start web server 

     mix do deps.get, compile
 mix phoenix.start

When running in production, use protocol consolidation for increased performance:

   MIX_ENV=prod mix compile.protocols
   MIX_ENV=prod elixir -pa _build/prod/consolidated -S mix phoenix.start

Router example

defmodule YourApp.Router do
  use Phoenix.Router

  plug Plug.Static, at: "/static", from: :your_app

  get "/pages/:page", Controllers.Pages, :show, as: :page
  get "/files/*path", Controllers.Files, :show

  resources "users", Controllers.Users do
    resources "comments", Controllers.Comments
  end

  scope path: "admin", alias: Controllers.Admin, helper: "admin" do
    resources "users", Users
  end
end

Controller examples

defmodule Controllers.Pages do
  use Phoenix.Controller

  def show(conn, %{"page" => "admin"}) do
    redirect conn, Router.page_path(page: "unauthorized")
  end
  def show(conn, %{"page" => page}) do
    render conn, title: "Showing page #{page}"
  end

end

defmodule Controllers.Users do
  use Phoenix.Controller

  def show(conn, %{"id" => id}) do
    text conn, "Showing user #{id}"
  end

  def index(conn, _params) do
    html conn, """
    <html>
      <body>
        <h1>Users</h1>
      </body>
    </html>
    """
  end
end

Views & Templates

Put simply, Phoenix Views render templates. Views also serve as a presentation layer for their templates where functions, alias, imports, etc are in context.

Rendering from the Controller

defmodule App.Controllers.Pages do
  use Phoenix.Controller

  def index(conn, _params) do
    render "index", message: "hello"
  end
end

By looking at the controller name App.Controllers.Pages, Phoenix will use App.Views.Pages to render lib/app/templates/pages/index.html.eex within the template lib/app/templates/layouts/application.html.eex. Let’s break that down:

Every keyword passed to render in the controller is available as an assign within the template, so you can use <%= @message %> in the eex template that is rendered in the controller example.

You may also create helper functions within your views or layouts. For exemple, the previous controller will use App.Views.Pages so you could have : 

defmodule App.Views do
  defmacro __using__(_options) do
    quote do
      use Phoenix.View, templates_root: unquote(Path.join([__DIR__, "templates"]))
      import unquote(__MODULE__)

      # This block is expanded within all views for aliases, imports, etc
      alias <%= application_module %>.Views
      
      def title, do: "Welcome to Phoenix!"
    end
  end

  # Functions defined here are available to all other views/templates
end

defmodule App.Views.Pages
  use App.Views

  def display(something) do 
    String.upcase(something)
  end
end

Which would allow you to use these functions in your template : <%= display(@message) %>, <%= title %>

Note that all views extend App.Views, allowing you to define functions, aliases, imports, etc available in all templates.

To read more about eex templating, see the elixir documentation.

More on request format

The template format to render is chosen based on the following priority:

Note that the layout and view templates would be chosen by matching conten types, ie application.[format].eex would be used to render show.[format].eex.

See this file for a list of supported mime types.

More on layouts

The “Layouts” module name is hardcoded. This means that App.Views.Layouts will be used and, by default, will render templates from lib/app/templates/layouts.

The layout template can be changed easily from the controller. For example :

defmodule App.Controllers.Pages do
  use Phoenix.Controller

  def index(conn, _params) do
    render "index", message: "hello", layout: "plain"
  end
end

To render the template’s content inside a layout, use the assign <%= @inner %> that will be generated for you.

You may also omit using a template with the following : 

render "index", message: "hello", layout: nil

Configuration

Phoenix provides a configuration per environment set by the MIX_ENV environment variable. The default environment Dev will be set if MIX_ENV does not exist.

Configuration file structure:

├── your_app/lib/config/
│   ├── config.ex          Base application configuration
│   ├── dev.ex
│   ├── prod.ex
│   └── test.ex
# your_app/lib/config/config.ex
defmodule YourApp.Config do
  use Phoenix.Config.App

  config :router, port: System.get_env("PORT")
  config :plugs, code_reload: false
  config :logger, level: :error
end

# your_app/lib/config/dev.ex
defmodule YourApp.Config.Dev do
  use YourApp.Config

  config :router, port: 4000
  config :plugs, code_reload: true
  config :logger, level: :debug
end

Configuration for SSL

To launch your application with support for SSL, just place your keyfile and certfile in the priv directory and configure your router with the following options:

# your_app/lib/config/prod.ex
defmodule YourApp.Config.Prod do
  use YourApp.Config

  config :router, port: 4040,
                  ssl: true,
                  otp_app: :your_app,
                  keyfile: "ssl/key.pem",
                  certfile: "ssl/cert.pem"
end

When you include the otp_app option, Plug will search within the priv directory of your application. If you use relative paths for keyfile and certfile and do not include the otp_app option, Plug will throw an error.

You can leave out the otp_app option if you provide absolute paths to the files.

Example:

Path.expand("../../../some/path/to/ssl/key.pem", __DIR__)

Configuration for Sessions

Phoenix supports a session cookie store that can be easily configured. Just add the following configuration settings to your application’s config module:

# your_app/lib/config/prod.ex
defmodule YourApp.Config.Prod do
  use YourApp.Config

  config :plugs, cookies: true

  config :cookies, key: "_your_app_key", secret: "valid_secret"
end

Then you can access session data from your application controllers. NOTE: that :key and :secret are required options.

Example:

defmodule Controllers.Pages do
  use Phoenix.Controller

  def show(conn, _params) do
    conn = put_session(:foo, "bar")
    foo = get_session(conn, :foo)

    text conn, foo
  end
end

Mix Tasks

mix phoenix                                    # List Phoenix tasks
mix phoenix.new     app_name destination_path  # Creates new Phoenix application
mix phoenix.routes  [MyApp.Router]             # Prints routes
mix phoenix.start   [MyApp.Router]             # Starts worker
mix phoenix --help                             # This help

Static Assets

Static asset support can be added by including Plug.Static in your router. Static assets will be served from the priv/static/ directory of your application.

  plug Plug.Static, at: "/static", from: :your_app

Documentation

API documentation is available at http://api.phoenixframework.org/

Development

There are no guidelines yet. Do what feels natural. Submit a bug, join a discussion, open a pull request.

Building documentation

  1. Clone docs repository into ../docs. Relative to your phoenix directory.
  2. Run MIX_ENV=docs mix run release_docs.exs in phoenix directory.
  3. Change directory to ../docs.
  4. Commit and push docs.

Feature Roadmap