Phoenix Framework

Build real-time web applications with Phoenix, LiveView, channels, and Elixir's concurrent architecture.

Core Patterns

LiveView

defmodule MyAppWeb.UserLive.Index do
  use MyAppWeb, :live_view

  alias MyApp.Accounts

  def mount(_params, _session, socket) do
    {:ok, assign(socket, users: Accounts.list_users())}
  end

  def handle_event("delete", %{"id" => id}, socket) do
    user = Accounts.get_user!(id)
    {:ok, _} = Accounts.delete_user(user)

    {:noreply, assign(socket, users: Accounts.list_users())}
  end
end

Controller

defmodule MyAppWeb.UserController do
  use MyAppWeb, :controller

  alias MyApp.Accounts

  def index(conn, _params) do
    users = Accounts.list_users()
    render(conn, :index, users: users)
  end

  def create(conn, %{"user" => user_params}) do
    case Accounts.create_user(user_params) do
      {:ok, user} ->
        conn
        |> put_status(:created)
        |> render(:show, user: user)

      {:error, changeset} ->
        conn
        |> put_status(:unprocessable_entity)
        |> render(:error, changeset: changeset)
    end
  end
end

Context

defmodule MyApp.Accounts do
  alias MyApp.Accounts.User
  alias MyApp.Repo

  def list_users do
    Repo.all(User)
  end

  def create_user(attrs) do
    %User{}
    |> User.changeset(attrs)
    |> Repo.insert()
  end
end

Best Practices

1. Use contexts for domain logic
2. Leverage LiveView for interactivity
3. Use Ecto changesets for validation
4. Implement proper error handling
5. Use channels for real-time features
6. Write ExUnit tests
7. Use telemetry for monitoring

Resources

• https://phoenixframework.org