Proposal: send_update accept cid

Hello, currently, to call send_update, i have to pass destination module and id (which is more of an html id than elixir side id - at least how i interpret it).

If i have live_component nested in another live component i do this currently

# Parent
<.live_component
  module={ChildComponent}
  id={"#{id}-child"}
  parent={{__MODULE__, id}}
/>
# Child
def handle_event("...", _, socket) do
  {parent_module, parent_id} = socket.assigns.parent
  send_update(parent_module, id: parent_id, action: my_payload)
end

I looked under the hood and all parent_module, id: parent_id does is gets cid to call further call correct callback (found by cid).

Wouldn’t it be easier just to

# Parent
<.live_component
  module={ChildComponent}
  parent={@myself}
/>
# Child
def handle_event("...", _, socket) do
  send_update(socket.assigns.parent, action: my_payload)
end

1. if no id is given cid is used as id
2. both live views and live components have cid
3. cid can be used to call send_update to any target (both live views and live components).
4. live views might aswell have update callback to handle those cases.

This also would move towards implementing this this:Provide a unified mechanism to message the parent/child · Issue #1597 · phoenixframework/phoenix_live_view · GitHub