From 7bc581e77a8d852a1d52b504301f1b2cf2607aff Mon Sep 17 00:00:00 2001
From: bergware <bergware@users.noreply.github.com>
Date: Tue, 28 Nov 2023 00:56:57 +0100
Subject: [PATCH] Publish messages only when active subscribers are present

---
 emhttp/plugins/dynamix/include/publish.php | 24 +++++++++-------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/emhttp/plugins/dynamix/include/publish.php b/emhttp/plugins/dynamix/include/publish.php
index 9dc5a44ce..198a77f3b 100644
--- a/emhttp/plugins/dynamix/include/publish.php
+++ b/emhttp/plugins/dynamix/include/publish.php
@@ -10,20 +10,16 @@
  */
 ?>
 <?
-function curl_socket($socket, $url, $message) {
-  $com = curl_init($url);
-  curl_setopt_array($com,[
-    CURLOPT_UNIX_SOCKET_PATH => $socket,
-    CURLOPT_POST=> 1,
-    CURLOPT_POSTFIELDS => $message,
-    CURLOPT_RETURNTRANSFER => true
-  ]);
-  $reply = curl_exec($com);
-  curl_close($com);
-  return $reply;
-}
-
 function publish($endpoint, $message, $len=1) {
-  return curl_socket("/var/run/nginx.socket", "http://localhost/pub/$endpoint?buffer_length=$len", $message);
+  $com = curl_init("http://localhost/pub/$endpoint?buffer_length=$len");
+  curl_setopt_array($com, [CURLOPT_UNIX_SOCKET_PATH => "/var/run/nginx.socket", CURLOPT_RETURNTRANSFER => true]);
+  preg_match('/subscribers: (\d+)/', curl_exec($com), $subs);
+  // only send message when active subscribers are present
+  if (!empty($subs[1]) && $subs[1]>0) {
+    curl_setopt_array($com, [CURLOPT_POST => 1, CURLOPT_POSTFIELDS => $message]);
+    $reply = curl_exec($com);
+  }
+  curl_close($com);
+  return $reply ?? '';
 }
 ?>