Added bUseTopicForEventDefaults to be able to use topic for filling i…

…n absent event data

src/vscp/common/vscp-client-mqtt.cpp

@@ -631,6 +631,8 @@ vscpClientMqtt::vscpClientMqtt(void)
   m_keepAlive           = 30;          // 30 seconds for keepalive
   // m_bCleanSession = false;       // Do not start with a clean session
 
+  m_bUseTopicForEventDefaults = false; // Do not use topic for event defaults
+
   // Defaults for timing
   m_timeoutConnection = 5000; // 5 seconds
   m_timeoutResponse   = 200;
@@ -1531,6 +1533,32 @@ vscpClientMqtt::handleMessage(const struct mosquitto_message *pmsg)
       return false;
     }
 
+    // If standard topic format is used, that is
+    // vscp/<vscp-guid>/<vscp-class>/<vscp-type>/index/zone/subzone
+    // and instructed to do so we can find the GUID, class and type from the topic
+    if (m_bUseTopicForEventDefaults) {
+      std::deque<std::string> vec;
+      vscp_split(vec, pmsg->topic, "/");
+      if (vec.size() >= 4) { // at least "vscp/<vscp-guid>/<vscp-class>/<vscp-type>"
+
+        // Assigne GUID from topic if all nills from event.
+        cguid guid(ex.GUID);
+        if (guid.isNULL()) {
+          vscp_getGuidFromStringToArray(ex.GUID, vec[1]);
+        }
+
+        // Assign class from topic if set to zeror in event.
+        if (!ex.vscp_class) {
+          ex.vscp_class = vscp_readStringValue(vec[2]);
+        }
+
+        // Assign type from topic if set to zero in event.
+        if (!ex.vscp_type) {
+          ex.vscp_type  = vscp_readStringValue(vec[3]);
+        }
+      }
+    }
+
     // If callback is defined send event
     if (isCallbackEvActive()) {
       m_callbackev(ev, getCallbackObj());

src/vscp/common/vscp-client-mqtt.h

@@ -591,6 +591,13 @@ class vscpClientMqtt : public CVscpClient {
   void setKeepAlive(uint16_t keepAlive) { m_keepAlive = keepAlive; };
   uint32_t getKeepAlive(void) { return m_keepAlive; };
 
+  /*!
+    Getter/setter for bUseTopicForEventDefaults
+  */
+ void setUseTopicForEventDefaults(bool b) { m_bUseTopicForEventDefaults = b; };
+ bool getUseTopicForEventDefaults(void) { return m_bUseTopicForEventDefaults; };
+ bool isUseTopicForEventDefaults(void) { return m_bUseTopicForEventDefaults; };
+
   /*!
     Getter for remote port
     @return remote host port.
@@ -658,7 +665,7 @@ class vscpClientMqtt : public CVscpClient {
   /*!
     Set parent disconnect callback
   */
-  void setFuncParentCallbackDisconnet(LPFN_PARENT_CALLBACK_DISCONNECT func) { m_parentCallbackDisconnect = func; };
+  void setFuncParentCallbackDisconnect(LPFN_PARENT_CALLBACK_DISCONNECT func) { m_parentCallbackDisconnect = func; };
 
   /*!
     Set parent publish callback
@@ -736,6 +743,19 @@ class vscpClientMqtt : public CVscpClient {
   */
   bool m_bJsonMeasurementAdd;
 
+  /*!
+    Use topic for defaults.
+
+    If the standard format for topics is used, that is
+    vscp/guid/class/type/index/zone/subzone 
+    the by enabling this guid, class and type information that
+    is absent from the received event can be filled in from the
+    MQTT topic of the message. This allows for very compact
+    MQTT messages while still preserving the full VSCP event
+    information.
+  */
+  bool m_bUseTopicForEventDefaults;
+
   /*!
     Mutex that protect CANAL interface when callbacks are defined
   */

src/vscp/common/vscphelper.cpp

@@ -4479,6 +4479,9 @@ vscp_convertJSONToEvent(vscpEvent *pEvent, std::string &strJSON)
     return false;
   }
 
+  // Initialize event
+  memset(pEvent, 0, sizeof(vscpEvent));
+
   try {
     auto j = json::parse(strJSON);
 
@@ -4632,6 +4635,9 @@ vscp_convertJSONToEventEx(vscpEventEx *pEventEx, std::string &strJSON)
     return false;
   }
 
+  // Initialize event
+  memset(pEventEx, 0, sizeof(vscpEventEx));
+
   try {
 
     auto j = json::parse(strJSON);

src/vscp/common/vscphelper.h

@@ -1621,12 +1621,26 @@ vscp_convertEventExToJSON(std::string &strJSON, vscpEventEx *pEventEx);
 
 /*!
  * Convert JSON string to event
+ *
+ * If a value is not found in the JSON string
+ * it will be set to zero. This means a value
+ * can be omitted in the JSON string. The only
+ * values that must be in the JSON string is
+ * class and type as long as the GUID is known 
+ * beforehand
  */
 bool
 vscp_convertJSONToEvent(vscpEvent *pEvent, std::string &strJSON);
 
 /*!
  * Convert JSON string to eventex
+ * 
+ * If a value is not found in the JSON string
+ * it will be set to zero. This means a value
+ * can be omitted in the JSON string. The only
+ * values that must be in the JSON string is
+ * class and type as long as the GUID is known 
+ * beforehand
  */
 bool
 vscp_convertJSONToEventEx(vscpEventEx *pEventEx, std::string &strJSONx);