adding :ets to keep track of current value

lib/clip/application.ex

@@ -14,9 +14,10 @@ defmodule Clip.Application do
       # Start the PubSub system
       {Phoenix.PubSub, name: Clip.PubSub},
       # Start the Endpoint (http/https)
-      ClipWeb.Endpoint
+      ClipWeb.Endpoint,
       # Start a worker by calling: Clip.Worker.start_link(arg)
       # {Clip.Worker, arg}
+      Clip.Currents
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

lib/clip/board.ex

@@ -0,0 +1,23 @@
+defmodule Clip.Board do
+
+  alias Clip.Currents
+
+  def init(user) do
+    Phoenix.PubSub.subscribe(Clip.PubSub, user.email)
+    Currents.get(user.email)
+  end
+
+  def paste(user, snippet) do
+    Phoenix.PubSub.broadcast(Clip.PubSub, user.email, {:snippet_pasted, %{snippet: snippet}})
+    Currents.set(user.email, snippet)
+  end
+
+  def normalize(pnumber, local_pref \\ "0351", country_pref \\ "0049") do
+    pnumber
+    |> String.replace(~r/^\s*\+/, "00")
+    |> String.replace(~r/\D/, "")
+    |> String.replace(~r/^00+/, "00")
+    |> String.replace(~r/^(?=[1-9])/, local_pref)
+    |> String.replace(~r/^0(?=[1-9])/, country_pref)
+  end
+end

lib/clip/currents.ex

@@ -0,0 +1,41 @@
+defmodule Clip.Currents do
+  use GenServer
+  require Logger
+
+  @purge_interval :timer.minutes(60)
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, %{}, name: ClipCurrents)
+  end
+
+  def init(opts) do
+    :ets.new(:users_clips, [:set, :named_table, :public])
+    state = %{
+      interval: opts[:purge_interval] || @purge_interval,
+      timer: nil
+    }
+    {:ok, schedule_purge(state)}
+  end
+
+  def set(email_addr, value) do
+    :ets.insert(:users_clips, {email_addr, value})
+    :ok
+  end
+
+  def get(email_addr) do
+    cur_val = case :ets.lookup(:users_clips, email_addr) do
+      [{^email_addr, value}] -> value
+      [] -> ""
+    end
+    {:ok, cur_val}
+  end
+
+  def handle_info(:purge, state) do
+    Logger.info("should purge old entries but doesn't, yet")
+    {:noreply, schedule_purge(state)}
+  end
+
+  defp schedule_purge(state) do
+    %{state | timer: Process.send_after(self(), :purge, state.interval)}
+  end
+end

lib/clip_web/live/board_live.ex

@@ -2,6 +2,7 @@ defmodule ClipWeb.BoardLive do
   use ClipWeb, :live_view
 
   alias Clip.Accounts
+  alias Clip.Board
 
   @impl true
   def render(assigns) do
@@ -17,29 +18,20 @@ defmodule ClipWeb.BoardLive do
   @impl true
   def mount(_params, session, socket) do
     user = Accounts.get_user_by_session_token(session |> Map.get("user_token"))
-    Phoenix.PubSub.subscribe(Clip.PubSub, user.email)
+    {:ok, snippet} = Board.init(user)
-    {:ok, assign(socket, snippet: "", current_user: user)}
+    {:ok, assign(socket, snippet: snippet, current_user: user)}
-  end
-
-  defp normalize(pnumber, local_pref \\ "0351", country_pref \\ "0049") do
-    pnumber
-    |> String.replace(~r/^\s*\+/, "00")
-    |> String.replace(~r/\D/, "")
-    |> String.replace(~r/^00+/, "00")
-    |> String.replace(~r/^(?=[1-9])/, local_pref)
-    |> String.replace(~r/^0(?=[1-9])/, country_pref)
   end
 
   @impl true
   def handle_event("normalize", _, %{assigns: %{snippet: snippet, current_user: user}} = socket) do
-    norm_snipp = normalize(snippet)
+    norm_snipp = Board.normalize(snippet)
-    Phoenix.PubSub.broadcast(Clip.PubSub, user.email, {:snippet_pasted, %{snippet: norm_snipp}})
+    Board.paste(user, norm_snipp)
     {:noreply, assign(socket, snippet: snippet)}
   end
 
   @impl true
   def handle_event("paste", %{"snippet" => snippet}, %{assigns: %{current_user: user}} = socket) do
-    Phoenix.PubSub.broadcast(Clip.PubSub, user.email, {:snippet_pasted, %{snippet: snippet}})
+    Board.paste(user, snippet)
     {:noreply, assign(socket, snippet: snippet)}
   end