Pow v1.0.16 PowPersistentSession.Plug.Cookie View Source

This plug will handle persistent user sessions with cookies.

By default, the cookie will expire after 30 days. The cookie expiration will be renewed on every request where a user is assigned to the conn. The token in the cookie can only be used once to create a session.

If an assigned private :pow_session_metadata key exists in the conn with a keyword list containing a :fingerprint key, that fingerprint value will be set along with the user clause as the persistent session value as {[id: user_id], session_metadata: [fingerprint: fingerprint]}.

Example

defmodule MyAppWeb.Endpoint do

# ...

plug Pow.Plug.Session, otp_app: :my_app

plug PowPersistentSession.Plug.Cookie

#...

end

Configuration options

  • :persistent_session_store - see PowPersistentSession.Plug.Base

  • :cache_store_backend - see PowPersistentSession.Plug.Base

  • :persistent_session_cookie_key - session key name. This defaults to "persistent_session_cookie". If :otp_app is used it'll automatically prepend the key with the :otp_app value.

  • :persistent_session_ttl - used for both backend store and max age for cookie. See PowPersistentSession.Plug.Base for more.

  • :persistent_session_cookie_opts - keyword list of cookie options, see Plug.Conn.put_resp_cookie/4 for options. The default options are [max_age: max_age, path: "/"] where :max_age is the value defined in :persistent_session_ttl.

  • :persistent_session_cookie_expiration_timeout - integer value in seconds for how much time should go by before cookie should expire after the token is fetched in authenticate/2. Defaults to 10.

Custom metadata

You can assign a private :pow_persistent_session_metadata key in the conn with custom metadata as a keyword list. The only current use this has is to set :session_metadata that'll be passed on as :pow_session_metadata for new session generation.

  session_metadata =
    conn.private
    |> Map.get(:pow_session_metadata, [])
    |> Keyword.take([:first_seen_at])

  Plug.Conn.put_private(conn, :pow_persistent_session_metadata, session_metadata: session_metadata)

This ensure that you are able to keep session metadata consistent between browser sessions.

When a persistent session token is used, the :pow_persistent_session_metadata assigns key in the conn will be populated with a :session_metadata keyword list so that the session metadata that was pulled from the persistent session can be carried over to the new persistent session. :fingerprint will always be ignored as to not record the old fingerprint.

Link to this section Summary

Functions

Authenticates a user with the persistent session cookie.

Sets a persistent session cookie with an auto generated token.

Expires the persistent session cookie.

Link to this section Functions

Link to this function

authenticate(conn, config)

View Source
authenticate(Plug.Conn.t(), Pow.Config.t()) :: Plug.Conn.t()

Authenticates a user with the persistent session cookie.

If a persistent session cookie exists, it'll fetch the credentials from the persistent session cache.

After the value is fetched from the cookie, it'll be updated to expire after the value of :persistent_session_cookie_expiration_timeout so invalid cookies will be deleted eventually. This timeout prevents immediate deletion of the cookie so in case of multiple simultaneous requests, the cache has time to update the value.

If credentials was fetched successfully, the token in the cache is deleted, a new session is created, and create/2 is called to create a new persistent session cookie. This will override any expiring cookie.

If a :session_metadata keyword list is fetched from the persistent session metadata, all the values will be merged into the private :pow_session_metadata key in the conn.

The expiration date for the cookie will be reset on each request where a user is assigned to the conn.

Link to this function

create(conn, user, config)

View Source
create(Plug.Conn.t(), map(), Pow.Config.t()) :: Plug.Conn.t()

Sets a persistent session cookie with an auto generated token.

The token is set as a key in the persistent session cache with the id fetched from the struct. Any existing persistent session will be deleted first with delete/2.

If an assigned private :pow_session_metadata key exists in the conn with a keyword list containing a :fingerprint value, then that value will be set in a :session_metadata keyword list in the persistent session metadata. The value will look like: {[id: user_id], session_metadata: [fingerprint: fingerprint]}

The unique cookie id will be prepended by the :otp_app configuration value, if present.

Expires the persistent session cookie.

If a persistent session cookie exists it'll be updated to expire immediately, and the token in the persistent session cache will be deleted.