Reauthorization plug

[danschultzer]

Resolves #116 and supersedes #139

This adds a reauthorization plug and additional logic that makes it very easy to enable PowPersistentSession.

In short, you just have to add this to your pipeline:

defmodule MyAppWeb.Router do
  use Phoenix.Router
  # ...

  pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug :fetch_flash
    plug :protect_from_forgery
    plug :put_secure_browser_headers
    plug PowAssent.Plug.Reauthorization,
      handler: PowAssent.Phoenix.ReauthorizationPlugHandler
  end

  # ...
end

A cookie will be stored when the user authorizes through a provider. Once the session has expired, the user will then be redirected back to the provider for reauthorization (happens after they have been redirected to the user_not_authenticated_path/1 path).

If you instead want to use PowPersistentSession, all you have to do is this:

defmodule MyAppWeb.Router do
  use Phoenix.Router
  # ...

  pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug :fetch_flash
    plug :protect_from_forgery
    plug :put_secure_browser_headers
    plug :pow_assent_persistent_session
  end

  defp pow_assent_persistent_session(conn, _opts) do
    PowAssent.Plug.put_create_session_callback(conn, fn conn, _provider, _config ->
      PowPersistentSession.Plug.create(conn, Pow.Plug.current_user(conn))
    end)
  end

  # ...
end

One last detail missing is to remove the cookie when the user logs out.