Are you using GitHub - pow-auth/pow: Robust, modular, and extendable user authentication system · GitHub to render the button?
Schultzer
Kurisu
I’m using the template assignment @current_user to check if user is authenticated and to render the buttons I use Routes.pow_session_path/2.
I think it is equivalent to what is said in your link.
Anyway I just pasted exactly the code of the link in my template and I get the same behaviour…
here is my initial code to show login or logout button:
<%= if @current_user do %>
<%= link @current_user.alias, to: Routes.my_profile_path(@conn, :show) %>
<%= link "Déconnexion", to: Routes.pow_session_path(@conn, :delete), method: :delete %>
<% else %>
<%= link "Connexion", to: Routes.pow_session_path(@conn, :new) %>
<% end %>
Kurisu
I should admit that admit it is not a big problem since clicking on the sign_out button won’t make any trouble… The visitor is just redirected to the login page. Another solution I found while googling is to use some js code to disable the browser back button after user logged out.
danschultzer
Pow Core Team
You need to set the cache control header to prevent the browser cache. You can run Plug.Conn.put_resp_header(conn, "cache-control", "no-cache, no-store, must-revalidate") in a plug for the relevant controllers/actions, or in a plug for the whole endpoint. Back button will fetch cached page unless the server has requested that the page doesn’t get cached.
Kurisu
This is the perfect solution for me. I think I will write a plug that check if the user is authenticated then and only then send the header that tells the browser not to cache the given pages
Thanks for pointing me in the right direction.
Kurisu
I would like to preload an association on authenticated user.
Please where can I add the preload instruction for Pow to call it each time an user authenticate?
Edit:
The purpose is to be able to use something like @current_user.profile.avatar in some template later.
Kurisu
I add a custom autheticate/1 to my user context but now I have this error when trying to authenticate:
# protocol Ecto.Queryable not implemented for %Core.Accounts.User
Core.Accounts.User is my user schema
Here is the custom autheticate/1 function:
def authenticate(params) do
user = pow_authenticate(params)
cond do
user == nil -> nil
true -> user |> preload(:profile)
end
end
Please any suggestion on how to achieve what I to implement (loading child association on user)?
Edit:
Now it is okay 
I was calling Ecto.Query.preload instead of Repo.preload.
Here is the correct custom function that finally works.
def authenticate(params) do
user = pow_authenticate(params)
cond do
user == nil -> nil
true -> Repo.preload(user, :profile)
end
end
Maybe it is a good idea to add this in some guide to help newbies that want to preload associations with authenticated user.
danschultzer
Pow Core Team
Great job! However, I would recommend a plug like this to make it easier for you instead of the custom authenticate/1 method:
defmodule MyAppWeb.LoadProfilePlug do
@doc false
@spec init(any()) :: any()
def init(opts), do: opts
@doc false
@spec call(Conn.t(), atom()) :: Conn.t()
def call(conn, _opts) do
config = Pow.Plug.fetch_config(conn)
case Pow.Plug.current_user(conn, config) do
nil ->
conn
user ->
preloaded_user = MyApp.Repo.preload(user, :profile)
Pow.Plug.assign_current_user(conn, preloaded_user, config)
end
end
end
And then you can call it across your whole endpoint (you could also set it on just the routes where you know will require the profile preloaded):
defmodule MyAppWeb.Endpoint do
use Phoenix.Endpoint, otp_app: :my_app
# ...
plug Plug.Session,
store: :cookie,
key: "_my_app_key",
signing_salt: "secret"
plug Pow.Plug.Session, otp_app: :my_app
plug MyAppWeb.LoadProfilePlug
# ...
end
If you use a custom authenticate/1 method, then you’ll store the profile along with the user struct in the credentials cache so you have to make sure that all updates of the user struct also has the preloaded profile. This means that you should at least also add a custom update/2 method there, since if users update their profile through the pow registration controller, the cached user struct will be updated with the returning struct from update/2. By using a plug you can completely eliminate this since you’ll fetch the profile directly from the DB each time (and this also prevents that the profile can become out of date if there is some action that may update it, but doesn’t refresh the user in the credentials cache).
elalaouifaris
Hi,
Newbie pow question here! (Thanks for the awesome work on this by the way)
I just read around a bit about pow and it looks really nice.
I’m working my way trough my first real Phoenix project. I would like to have accounts authentication with users and parent organizations. I have seen in the documentation some examples that mention this (in the invitation section). Is there any introduction level tutorial on how to set it up correctly?
I tried using the mix pow.install with organizations option.
How do you proceed to add actual users from there? I’m trying to find the “recommended” ways for doing these things before hacking my way in and making obvious mistakes.
I can contribute to documentation on this aspect if it’s helpful.
Thanks!
danschultzer
Pow Core Team
That example is just for custom user schemas. The example is misleading though with the organizations table, and I’ve changed them to mix pow.install -r MyApp.Repo Accounts.Account accounts.
There is no recommended way, but I’ve added some step-by-step instructions here to get you started: Guide on how to set up organization · Issue #11 · pow-auth/pow_site · GitHub
It would be great to have a guide about this on powauth.com, so feel free to comment on the above issue with your experience 