Disconnect/quit handler in LiveView process

kim366 · September 2, 2022, 12:58am

I am looking for an equivalent to mount in a LiveView module that is called when the client disconnects whether by losing internet connection or leaving the page. In response to this event I want to execute server-side code. From a lot of googling I could not find this functionality.

This is probably a bad comparison but where I have used equivalent functionality before is Vue where you have mounted and unmounted: Lifecycle Hooks | Vue.js.

Cheers, Kim

mindok · September 2, 2022, 1:13am

It’s all about knowing the right keywords in google! There’s a discussion about this in the following GitHub issue:

github.com/phoenixframework/phoenix_live_view

There is no unmount callback on Phoenix.LiveView

opened 03:55AM - 24 Mar 19 UTC

closed 04:00AM - 24 Mar 19 UTC

skylerparr

### Actual behavior There is a callback to track when the socket has been `moun…t`ed, but there is no callback to be notified when the socket has been `unmount`ed. This makes cleaning up the user's session difficult (like committing unsaved work to a database when the user closes a browser tab, for example). ### Expected behavior Have a callback for when the socket is unmounted. ``` def unmount(session, socket) do # clean up or post disconnect operation {:noreply, socket} end ```

In short, you use another process to monitor the LiveView process and it receives events when the LiveView process terminates.