Switch to keep alive interval and add unsaved changes warning

configurator/actions-for-nautilus-configurator.html

@@ -37,17 +37,20 @@
 
 		/*
 		 * Because this is a local UI tightly related to
-		 * backend server that it is using, unload should
-		 * stop that server :)
+		 * backend server that it is using, pings will
+		 * keep it alive :)
 		 */
-		function onUnload(event) {
+		const KEEP_ALIVE_INTERVAL = 7500;
+
+		function sendKeepAlive() {
 			$.ajax({
-				url: '/terminate',
+				url: '/keep-alive',
 				type: 'post',
-				data: ""
-			});
+				data: ''
+			})
+			setTimeout(sendKeepAlive, KEEP_ALIVE_INTERVAL);
 		}
-		addEventListener("beforeunload", onUnload);
+		sendKeepAlive();
 
 		let editor;
 

configurator/actions-for-nautilus-configurator.py

@@ -5,10 +5,12 @@
 import os
 import shutil
 import datetime
+import threading
 
 PORT = 8000
 HOME = os.environ.get('HOME')
 JQUERY = os.environ.get('JQUERY')
+KEEP_ALIVE_TIMEOUT_S = 10
 
 # config_html = "./actions-for-nautilus-configurator.html"
 # cmdline_help = "./command-line-help.html"
@@ -146,10 +148,22 @@ def restart_nautilus(self):
     return
 
 
-def terminate_server(self):
-    self.send_error(204, "terminated")
+keep_alive_timer = None
+
+def restart_dead_interval(server):
+    global keep_alive_timer
+
+    if keep_alive_timer is not None:
+        keep_alive_timer.cancel()
+
+    keep_alive_timer = threading.Timer(KEEP_ALIVE_TIMEOUT_S, server.shutdown)
+    keep_alive_timer.start()
+
+def keep_alive_server(self):
+    restart_dead_interval(self.server)
+
+    self.send_response(200, "OK")
     self.end_headers()
-    self.server.shutdown()
     return
 
 
@@ -197,7 +211,7 @@ def forbidden(self):
 
 actions = {
     "/restart": restart_nautilus,
-    "/terminate": terminate_server,
+    "/keep-alive": keep_alive_server,
     "/config": save_config
 }
 
@@ -226,6 +240,7 @@ def do_POST(self):
     print("localhost:" + str(httpd.server_address[1]))
     try:
         httpd.serve_forever()
+        restart_dead_interval(httpd)
     except KeyboardInterrupt:
         httpd.shutdown()
     print("terminating")

configurator/javascript/jsonEditorHooks.js

@@ -131,6 +131,20 @@ function finalizeEditorConfig(e) {
 	save_button.disabled = true
 	button_holder.appendChild(save_button);
 
+	/*
+	 * Warn if exiting with unsaved changes
+	 */
+	window.addEventListener(
+    'beforeunload',
+    function (e) {
+      if (save_button.disabled) return;
+      e.preventDefault();
+      e.returnValue = 'You have unsaved changes!';
+			return true
+    },
+    true
+  );
+
 	/*
 	 * Create a edit JSON config button and disable it
 	 */