phoenix-patterns

# Phoenix Patterns

Master Phoenix Framework patterns to build well-structured, maintainable web applications in Elixir.

## Context Design

Contexts are dedicated modules that expose and group related functionality:

```elixir
defmodule MyApp.Accounts do
  @moduledoc """
  The Accounts context handles user management and authentication.
  """

  alias MyApp.Repo
  alias MyApp.Accounts.User

  def list_users do
    Repo.all(User)
  end

  def get_user!(id), do: Repo.get!(User, id)

  def get_user_by_email(email) do
    Repo.get_by(User, email: email)
  end

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

  def update_user(%User{} = user, attrs) do
    user
    |> User.changeset(attrs)
    |> Repo.update()
  end

  def delete_user(%User{} = user) do
    Repo.delete(user)
  end

  def change_user(%User{} = user, attrs \\ %{}) do
    User.changeset(user, attrs)
  end
end
```

## Controller Patterns

```elixir
defmodule MyAppWeb.UserController do
  use MyAppWeb, :controller

  alias MyApp.Accounts
  alias MyApp.Accounts.User

  action_fallback MyAppWeb.FallbackController

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

  def create(conn, %{"user" => user_params}) do
    with {:ok, %User{} = user} <- Accounts.create_user(user_params) do
      conn
      |> put_status(:created)
      |> put_resp_header("location", ~p"/api/users/#{user}")
      |> render(:show, user: user)
    end
  end

  def show(conn, %{"id" => id}) do
    user = Accounts.get_user!(id)
    render(conn, :show, user: user)
  end

  def update(conn, %{"id" => id, "user" => user_params}) do
    user = Accounts.get_user!(id)

    with {:ok, %User{} = user} <- Accounts.update_user(user, user_params) do
      render(conn, :show, user: user)
    end
  end

  def delete(conn, %{"id" => id}) do
    user = Accounts.get_user!(id)

    with {:ok, %User{}} <- Accounts.delete_user(user) do
      send_r