arduino-libraries · hmueller01 · Nov 12, 2024 · Nov 12, 2024
diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
@@ -411,7 +411,12 @@ int MqttClient::unsubscribe(const String& topic)
  return unsubscribe(topic.c_str());
 }

-void MqttClient::poll()
+/**
+ * @brief  Call poll() regularly to receive MQTT messages and send MQTT keep alives.
+ * @return 0 - client is no longer connected.
+ *         1 - client is still connected.
+ */
+int MqttClient::poll()
 {
  if (clientAvailable() == 0 && !clientConnected()) {
    _rxState = MQTT_CLIENT_RX_STATE_READ_TYPE;
@@ -441,8 +446,7 @@ void MqttClient::poll()
        if (_rxLengthMultiplier > (128 * 128 * 128L)) {
          // malformed
          stop();
-
-          return;
+          return 0;
        }

        if ((b & 0x80) == 0) { // length done
@@ -469,7 +473,7 @@ void MqttClient::poll()

          if (malformedResponse) {
            stop();
-            return;
+            return 0;
          }

          if (_rxType == MQTT_PUBLISH) {
@@ -538,12 +542,12 @@ void MqttClient::poll()
          if (_rxMessageQoS) {
            if (_rxLength < (_rxMessageTopicLength + 2)) {
              stop();
-              return;
+              return 0;
            }
          } else {
            if (_rxLength < _rxMessageTopicLength) {
              stop();
-              return;
+              return 0;
            }
          }

@@ -645,6 +649,8 @@ void MqttClient::poll()
      stop();
    }
  }
+
+  return _connected ? 1 : 0;
 }

 int MqttClient::connect(IPAddress ip, uint16_t port)
@@ -1150,6 +1156,10 @@ uint8_t MqttClient::clientConnected()
  return _client->connected();
 }

+/**
+ * @brief  Return number of available received bytes.
+ * @return Number of available bytes received.
+ */
 int MqttClient::clientAvailable()
 {
  return _client->available();

diff --git a/src/MqttClient.h b/src/MqttClient.h
@@ -76,7 +76,7 @@ class MqttClient : public Client {
  int unsubscribe(const char* topic);
  int unsubscribe(const String& topic);

-  void poll();
+  int poll();

  // from Client
  virtual int connect(IPAddress ip, uint16_t port = 1883);