# Source
# https://github.com/elixir-ecto/db_connection/commit/eae538ec06b4603f69b28bf00f3603a3e4ecd1a5.patch

From eae538ec06b4603f69b28bf00f3603a3e4ecd1a5 Mon Sep 17 00:00:00 2001
From: Paulo Daniel Gonzalez 
Date: Fri, 2 Sep 2022 14:14:11 -0500
Subject: [PATCH] Add example implementation for a connection_listener

---
  lib/db_connection.ex | 32 ++++++++++++++++++++++++++++++++
  1 file changed, 32 insertions(+)

diff --git a/lib/db_connection.ex b/lib/db_connection.ex
index 2356017..a2c79d5 100644
--- a/lib/db_connection.ex
+++ b/lib/db_connection.ex
@@ -433,6 +433,38 @@ defmodule DBConnection do
    `pid` for connection crashes. So it is recommended to monitor the connected
    `pid` if you want to track all disconnections.

+  Here is an example of a `connection_listener` implementation:
+
+    defmodule DBConnectionListener do
+      use GenServer
+
+      def start_link() do
+        GenServer.start_link(__MODULE__, [], name: {:global, "db_connection_listener"})
+      end
+
+      @impl true
+      def init(stack) when is_list(stack) do
+        {:ok, stack}
+      end
+
+      @impl true
+      def handle_call(:read_state, _from, state) do
+        {:reply, state, state}
+      end
+
+      @impl true
+      def handle_info(msg, state) do
+        {:noreply, [msg | state]}
+      end
+    end
+
+  You can then start it, pass it into a `DBConnection.start_link/1` and when needed
+  can query the notifications:
+
+    {:ok, connection_listener} = DBConnectionListener.start_link([])
+    {:ok, _conn} = DBConnection.start_link(SomeModule, [connection_listeners: [connection_listener]])
+    notifications = GenServer.call({:global, "db_connection_listener"}, :read_state)
+