Extend attach_hook/4 in LiveComponents

kraleppa · October 13, 2025, 7:18am

Hey all

Currently, attach_hook/4 in LiveComponents supports only :handle_event and :after_render stages. HexDocs

I’m wondering if it would be possible to support all the rest (like update/2 or handle_async/3) of the LiveComponent lifecycle stages?

Is there a specific reason (technical or design) why LiveComponents are restricted to just those two hook stages?

Thanks!

steffend · October 13, 2025, 9:05am

I don’t think there’s a technical reason blocking it. Adding support for handle_async might be as easy as adding it in line 98 here:

github.com/phoenixframework/phoenix_live_view

lib/phoenix_live_view/lifecycle.ex

ecb987460


      
          
            Got: #{inspect(stage)}
            """
          end
          
          defp hook!(id, stage, fun) when is_atom(stage) and is_function(fun) do
            %{id: id, stage: stage, function: fun}
          end
          
          defp lifecycle(socket, stage) do
            if Utils.cid(socket) && stage not in [:after_render, :handle_event] do
              raise ArgumentError, "lifecycle hooks are not supported on stateful components."
            end
          
            Map.fetch!(socket.private, @lifecycle)
          end
          
          defp update_lifecycle(socket, stage, fun) do
            lifecycle = lifecycle(socket, stage)
            new_lifecycle = Map.update!(lifecycle, stage, fun)
            put_lifecycle(socket, new_lifecycle)

For update, more changes would be necessary, but if you want to look into it, a PR is welcome (I’d probably split it into two separate PRs though!).