Hermanverschooten
Problem with life cycle hooks
I am a bit stumped…
I am trying to attach a life cycle hook to close flash messages automatically after 5 seconds.
I have this code:
defmodule MailManWeb.FlashLive do
def on_mount(:default, _params, _session, socket) do
{:cont,
socket
|> Phoenix.LiveView.attach_hook(:flash, :handle_params, &send_close/3)
|> Phoenix.LiveView.attach_hook(:flash, :handle_info, &info/2)}
end
def send_close(_params, _uri, socket) do
Enum.each(Phoenix.LiveView.Utils.get_flash(socket), fn {key, _msg} ->
Process.send_after(self(), {:close_flash, key}, 5000)
end)
{:cont, socket}
end
defp info({:close_flash, key}, socket) do
{:cont, socket |> Phoenix.LiveView.clear_flash(key)}
end
defp info(_, socket), do: {:cont, socket}
end
I initially had the Enum.each in the on_mount, but then it wasn’t executed when using a patch navigation.
Problem is now, it is not working on navigate navigation, I get a no function clause matching error on handle_info, it is as if the hook isn’t set.
I tried moving the attach_hook into the send_close function, but then it explodes on patch because the hook is already set.
What am I missing?
Marked As Solved
Hermanverschooten
OMG, I found it and once I did it is so logical!
I thought it might have been a bug introduced in rc of live_view, so I created a test app with 0.20.17. I created the hook added 2 pages with just a button that put_flash and push_navigate, immediately I noticed that upon clicking the flash would close after 5 seonds - great - but I also got
[debug] warning: undefined handle_info in TestHookWeb.Page2Live. Unhandled message: {:close_flash, "info"}
This decided me to try and return {:halt, ...} from info/2 and that fixed it!
Returning {:cont, ...} made live_view continue the event where it failed because I have an handle_info/2 but not for that event.
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