Use when applying Phoenix Framework best practices including context design, controller patterns, and application architecture. Use when building Phoenix applications.
Master Phoenix Framework patterns to build well-structured, maintainable web applications in Elixir.
Contexts are dedicated modules that expose and group related functionality:
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
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_resp(conn, :no_content, "")
end
end
end
defmodule MyAppWeb.FallbackController do
use MyAppWeb, :controller
def call(conn, {:error, :not_found}) do
conn
|> put_status(:not_found)
|> put_view(json: MyAppWeb.ErrorJSON)
|> render(:"404")
end
def call(conn, {:error, %Ecto.Changeset{} = changeset}) do
conn
|> put_status(:unprocessable_entity)
|> put_view(json: MyAppWeb.ChangesetJSON)
|> render(:error, changeset: changeset)
end
def call(conn, {:error, :unauthorized}) do
conn
|> put_status(:unauthorized)
|> put_view(json: MyAppWeb.ErrorJSON)
|> render(:"401")
end
end
defmodule MyAppWeb.Router do
use MyAppWeb, :router
pipeline :browser do
plug :accepts, ["html"]
plug :fetch_session
plug :fetch_live_flash
plug :put_root_layout, html: {MyAppWeb.Layouts, :root}
plug :protect_from_forgery
plug :put_secure_browser_headers
end
pipeline :api do
plug :accepts, ["json"]
plug MyAppWeb.Plugs.Authenticate
end
pipeline :admin do
plug MyAppWeb.Plugs.RequireAdmin
end
scope "/", MyAppWeb do
pipe_through :browser
get "/", PageController, :home
end
scope "/api", MyAppWeb do
pipe_through :api
resources "/users", UserController, except: [:new, :edit]
scope "/admin" do
pipe_through :admin
resources "/settings", Admin.SettingsController
end
end
end
defmodule MyAppWeb.Plugs.Authenticate do
import Plug.Conn
def init(opts), do: opts
def call(conn, _opts) do
with ["Bearer " <> token] <- get_req_header(conn, "authorization"),
{:ok, user} <- MyApp.Accounts.verify_token(token) do
assign(conn, :current_user, user)
else
_ ->
conn
|> put_status(:unauthorized)
|> Phoenix.Controller.put_view(json: MyAppWeb.ErrorJSON)
|> Phoenix.Controller.render(:"401")
|> halt()
end
end
end
Use phoenix-patterns when you need to: