Phoenix LiveView cookie without authentication

[lehoff]

Hi,

I am trying the help a local restaurant by putting up a simple website for ordering take-away.

I want to leverage LiveView to show the current order items on the right hand side.

I need to have a cookie based solution that preserves the order items when clicking on links (sub-menus for starters, mains, desserts, etc).
So far I have not been able to make it work and I have not been able to find any solutions/hints online.
I have tried using the _csrf_token, but it is not always present in the session.

I want to avoid forcing the customer to create a login - just have them state a mail/cell number so that the restaurant can tell when their order is ready. Everything is paid for at pick-up, no online payment (I’m just doing this as a favour to the local restaurant, so not going to open that box of goodies).
I have found several authentication related solutions for LiveView, but that is not the use case I’m after.

As far as I can tell it would be possible to control this better using straight Phoenix as the problem is related to the use of websockets in LiveView. I just fancy the idea of a live update of the current order in the style of LiveView. If it is impossible I will just revert to “plain” Phoenix, but that feels like an unnecessary defeat.

I am not an expert in Phoenix (LiveView) so please forgive me for my ignorance.
I hope that I have explained the problem well enough.

Cheers,
Torben

[dnsbty]

Because the LiveView isn’t reloading the page, it isn’t really possible to set cookies server side.

Your best bet would be to either use JavaScript to set the cookie client side or to use AJAX to make it work similar to the solution outlined here:

Persistent session data in Phoenix LiveView

[mindok]

Hi Torben,

There’s a discussion here that may give you a few ideas:

PhoenixLiveSession: Plug sessions with LiveView integration + PubSub support

Hey folks, I’ve just published a little library called PhoenixLiveSession. What is it? PhoenixLiveSession is a drop-in replacement for the default Plug.Session stores, comes with LiveView integration and Phoenix.PubSub support. Why did I create it? My motivation for this was a client project in which I wanted to implement a shopping cart using LiveView. I wanted to store the shopping cart data in the user session, but so far, doing this with LiveView required some hacky JavaScript trickery …

Or, you could use javascript hooks as described here: Persistent session data in Phoenix LiveView – The Pug Automatic - it’s a bit more roundabout, particularly if you want to share session state between liveviews.

[mindok]

… mid-air collision!

[wmnnd]

@lehoff: If you give PhoenixLiveSession a try, let me know how it worked for you

[lehoff]

@wmnnd

We got it to work with PhoenixLiveViewSession and managed to cut it down to the bare minimals:

• Add the dependency.
• Simple do-nothing handling of {:live_session_updated, session} in handle_info:

def handle_info({:live_session_updated, session}, socket) do
    {:noreply, socket}
end

• Use PhoenLiveSession.maybe_subscribe/2 in mount/3:

socket = assign(
  socket,
  dishes: DatabaseLogic.get_dishes
)
|> PhoenixLiveSession.maybe_subscribe(session)

We have used for a long time now and it just works™.

[wmnnd]

Awesome