develop a LiveViewMonitor to monitor LiveView shutdowns

lib/intisync/application.ex

@@ -11,9 +11,7 @@ defmodule Intisync.Application do
       IntisyncWeb.Telemetry,
       {DNSCluster, query: Application.get_env(:intisync, :dns_cluster_query) || :ignore},
       {Phoenix.PubSub, name: Intisync.PubSub},
-      # Start a worker by calling: Intisync.Worker.start_link(arg)
-      # {Intisync.Worker, arg},
-      # Start to serve requests, typically the last entry
+      {IntisyncWeb.LiveViewMonitor, %{}},
       IntisyncWeb.Endpoint
     ]
 

lib/intisync_web/channels/live_view_monitor.ex

@@ -0,0 +1,31 @@
+defmodule IntisyncWeb.LiveViewMonitor do
+  use GenServer
+
+  def start_link(init_arg) do
+    GenServer.start_link(__MODULE__, init_arg, name: {:global, __MODULE__})
+  end
+
+  def init(_) do
+    {:ok, %{views: %{}}}
+  end
+
+  def monitor(pid, view_module, meta) do
+    server_pid = GenServer.whereis({:global, __MODULE__})
+    GenServer.call(server_pid, {:monitor, pid, view_module, meta})
+  end
+
+  def handle_call({:monitor, pid, view_module, meta}, _, %{views: views} = state) do
+    mref = Process.monitor(pid)
+    {:reply, :ok, %{state | views: Map.put(views, pid, {view_module, meta, mref})}}
+  end
+
+  def handle_info({:DOWN, _ref, :process, pid, reason}, state) do
+    {{module, meta, mref}, new_views} = Map.pop(state.views, pid)
+
+    Task.start(fn -> module.unmount(reason, meta) end)
+
+    Process.demonitor(mref)
+
+    {:noreply, %{state | views: new_views}}
+  end
+end