api specs

phoenix/lib/shooting_event_phx_web/controllers/events_controller.ex

@@ -0,0 +1,40 @@
+defmodule ShootingEventPhxWeb.EventsController do
+  use ShootingEventPhxWeb, :controller
+  alias ShootingEventPhx.Events
+
+  def stream(conn, _params) do
+    conn =
+      conn
+      |> put_resp_header("content-type", "text/event-stream")
+      |> put_resp_header("cache-control", "no-cache, no-transform")
+      |> put_resp_header("connection", "keep-alive")
+      |> put_resp_header("x-accel-buffering", "no")
+      |> send_chunked(200)
+
+    now = DateTime.utc_now() |> DateTime.truncate(:second) |> DateTime.to_iso8601()
+    {:ok, conn} = chunk(conn, "event: ready\ndata: {\"ts\":\"#{now}\"}\n\n")
+
+    :ok = Events.subscribe()
+    loop_stream(conn)
+  end
+
+  defp loop_stream(conn) do
+    receive do
+      {:state, ts} ->
+        case chunk(conn, "event: state\ndata: {\"ts\":\"#{ts}\"}\n\n") do
+          {:ok, conn} -> loop_stream(conn)
+          {:error, :closed} -> conn
+          {:error, _} -> conn
+        end
+    after
+      20_000 ->
+        now_unix = DateTime.utc_now() |> DateTime.to_unix()
+
+        case chunk(conn, ": ping #{now_unix}\n\n") do
+          {:ok, conn} -> loop_stream(conn)
+          {:error, :closed} -> conn
+          {:error, _} -> conn
+        end
+    end
+  end
+end