wiki/lib/wiki_web/controllers/user_registration_controller.ex

defmodule WikiWeb.UserRegistrationController do
  use WikiWeb, :controller

  alias Wiki.Accounts
  alias Wiki.Accounts.User
  alias WikiWeb.UserAuth

  plug :check_registration_enabled

  def check_registration_enabled(conn, _opts) do
    if Application.get_env(:wiki, :registration_enabled, true) do
      conn
    else
      conn
      |> send_resp(403, "Forbidden")
      |> halt()
    end
  end

  def new(conn, _params) do
    changeset = Accounts.change_user_registration(%User{})
    render(conn, "new.html", changeset: changeset)
  end

  def create(conn, %{"user" => user_params}) do
    case Accounts.register_user(user_params) do
      {:ok, user} ->
        {:ok, _} =
          Accounts.deliver_user_confirmation_instructions(
            user,
            &Routes.user_confirmation_url(conn, :confirm, &1)
          )

        conn
        |> put_flash(:info, "User created successfully.")
        |> UserAuth.log_in_user(user, user_params)

      {:error, %Ecto.Changeset{} = changeset} ->
        render(conn, "new.html", changeset: changeset)
    end
  end
end