Add command SetOption75 0/1 to switch between grouptopic

Add command SetOption75 0/1 to switch between grouptopic (0) using fulltopic replacing %topic% or (1) is cmnd/<grouptopic> (#6779)

tasmota/_changelog.ino

@@ -1,12 +1,13 @@
 /*********************************************************************************************\
  * 7.0.0.1 20191027
- * Remove references to versions before 6.x
+ * Remove references to versions before 6.0
  * Change default GUI to dark theme
  * Add command SetOption73 0/1 to re-enable HTTP Cross-Origin Resource Sharing (CORS) now default disabled (#6767)
  * Add frequency to ADE7953 energy monitor as used in Shelly 2.5 by ljakob (#6778)
  * Add command SetOption74 0/1 to enable DS18x20 internal pull-up and remove define DS18B20_INTERNAL_PULLUP (#6795)
  * Fix better control of RGB/White when SetOption37 >128, added Dimmer1 and Dimmer2 commands (#6714)
  * Add hide Alexa objects with friendlyname starting with '$' (#6722, #6762)
+ * Add command SetOption75 0/1 to switch between grouptopic (0) using fulltopic replacing %topic% or (1) is cmnd/<grouptopic> (#6779)
  *
  * 6.7.1.1 20191026
  * Change ArduinoSlave to TasmotaSlave (Experimental)

tasmota/settings.h

@@ -88,7 +88,7 @@ typedef union {                            // Restricted by MISRA-C Rule 18.4 bu
     uint32_t hardware_energy_total : 1;    // bit 22 (v6.6.0.15) - SetOption72 - Enable / Disable hardware energy total counter as reference (#6561)
     uint32_t cors_enabled : 1;             // bit 23 (v7.0.0.1)  - SetOption73 - Enable HTTP CORS
     uint32_t ds18x20_internal_pullup : 1;  // bit 24 (v7.0.0.1)  - SetOption74 - Enable internal pullup for single DS18x20 sensor
-    uint32_t spare25 : 1;
+    uint32_t grouptopic_mode : 1;          // bit 25 (v7.0.0.1)  - SetOption75 - GroupTopic replaces %topic% (0) or fixed topic cmnd/grouptopic (1)
     uint32_t spare26 : 1;
     uint32_t spare27 : 1;
     uint32_t spare28 : 1;

tasmota/support_command.ino

@@ -143,7 +143,7 @@ void CommandHandler(char* topicBuf, char* dataBuf, uint32_t data_len)
   bool grpflg = (strstr(topicBuf, Settings.mqtt_grptopic) != nullptr);
 
   char stemp1[TOPSZ];
-  GetFallbackTopic_P(stemp1, CMND, "");  // Full Fallback topic = cmnd/DVES_xxxxxxxx_fb/
+  GetFallbackTopic_P(stemp1, "");  // Full Fallback topic = cmnd/DVES_xxxxxxxx_fb/
   fallback_topic_flag = (!strncmp(topicBuf, stemp1, strlen(stemp1)));
 
   char *type = strrchr(topicBuf, '/');   // Last part of received topic is always the command (type)
@@ -718,6 +718,7 @@ void CmndSetoption(void)
                 WiFiSetSleepMode();        // Update WiFi sleep mode accordingly
                 break;
               case 18:                     // SetOption68 for multi-channel PWM, requires a reboot
+              case 25:                     // SetOption75 grouptopic change
                 restart_flag = 2;
                 break;
             }

tasmota/tasmota.ino

@@ -243,18 +243,26 @@ char* GetTopic_P(char *stopic, uint32_t prefix, char *topic, const char* subtopi
      prefix 4 = Cmnd fallback
      prefix 5 = Stat fallback
      prefix 6 = Tele fallback
+     prefix 8 = Cmnd topic
+     prefix 9 = Stat topic
+     prefix 10 = Tele topic
   */
   char romram[CMDSZ];
   String fulltopic;
 
   snprintf_P(romram, sizeof(romram), subtopic);
   if (fallback_topic_flag || (prefix > 3)) {
+    bool fallback = (prefix < 8);
     prefix &= 3;
     char stemp[11];
     fulltopic = GetTextIndexed(stemp, sizeof(stemp), prefix, kPrefixes);
     fulltopic += F("/");
-    fulltopic += mqtt_client;
-    fulltopic += F("_fb");                    // cmnd/<mqttclient>_fb
+    if (fallback) {
+      fulltopic += mqtt_client;
+      fulltopic += F("_fb");                  // cmnd/<mqttclient>_fb
+    } else {
+      fulltopic += topic;                     // cmnd/<grouptopic>
+    }
   } else {
     fulltopic = Settings.mqtt_fulltopic;
     if ((0 == prefix) && (-1 == fulltopic.indexOf(FPSTR(MQTT_TOKEN_PREFIX)))) {
@@ -282,9 +290,16 @@ char* GetTopic_P(char *stopic, uint32_t prefix, char *topic, const char* subtopi
   return stopic;
 }
 
-char* GetFallbackTopic_P(char *stopic, uint32_t prefix, const char* subtopic)
+char* GetGroupTopic_P(char *stopic, const char* subtopic)
+{
+  // SetOption75 0: %prefix%/nothing/%topic% = cmnd/nothing/<grouptopic>/#
+  // SetOption75 1: cmnd/<grouptopic>
+  return GetTopic_P(stopic, (Settings.flag3.grouptopic_mode) ? CMND +8 : CMND, Settings.mqtt_grptopic, subtopic);
+}
+
+char* GetFallbackTopic_P(char *stopic, const char* subtopic)
 {
-  return GetTopic_P(stopic, prefix +4, nullptr, subtopic);
+  return GetTopic_P(stopic, CMND +4, nullptr, subtopic);
 }
 
 char* GetStateText(uint32_t state)

tasmota/xdrv_01_webserver.ino

@@ -1910,9 +1910,10 @@ void HandleInformation(void)
 #endif
     WSContentSend_P(PSTR("}1" D_MQTT_CLIENT "}2%s"), mqtt_client);
     WSContentSend_P(PSTR("}1" D_MQTT_TOPIC "}2%s"), Settings.mqtt_topic);
-    WSContentSend_P(PSTR("}1" D_MQTT_GROUP_TOPIC "}2%s"), Settings.mqtt_grptopic);
+//    WSContentSend_P(PSTR("}1" D_MQTT_GROUP_TOPIC "}2%s"), Settings.mqtt_grptopic);
+    WSContentSend_P(PSTR("}1" D_MQTT_GROUP_TOPIC "}2%s"), GetGroupTopic_P(stopic, ""));
     WSContentSend_P(PSTR("}1" D_MQTT_FULL_TOPIC "}2%s"), GetTopic_P(stopic, CMND, mqtt_topic, ""));
-    WSContentSend_P(PSTR("}1" D_MQTT " " D_FALLBACK_TOPIC "}2%s"), GetFallbackTopic_P(stopic, CMND, ""));
+    WSContentSend_P(PSTR("}1" D_MQTT " " D_FALLBACK_TOPIC "}2%s"), GetFallbackTopic_P(stopic, ""));
   } else {
     WSContentSend_P(PSTR("}1" D_MQTT "}2" D_DISABLED));
   }

tasmota/xdrv_02_mqtt.ino

@@ -528,18 +528,19 @@ void MqttConnected(void)
     GetTopic_P(stopic, CMND, mqtt_topic, PSTR("#"));
     MqttSubscribe(stopic);
     if (strstr_P(Settings.mqtt_fulltopic, MQTT_TOKEN_TOPIC) != nullptr) {
-      GetTopic_P(stopic, CMND, Settings.mqtt_grptopic, PSTR("#"));
+      GetGroupTopic_P(stopic, PSTR("#"));  // SetOption75 0: %prefix%/nothing/%topic% = cmnd/nothing/<grouptopic>/# or SetOption75 1: cmnd/<grouptopic>
       MqttSubscribe(stopic);
-      GetFallbackTopic_P(stopic, CMND, PSTR("#"));
+      GetFallbackTopic_P(stopic, PSTR("#"));
       MqttSubscribe(stopic);
     }
 
     XdrvCall(FUNC_MQTT_SUBSCRIBE);
   }
 
   if (Mqtt.initial_connection_state) {
+    char stopic2[TOPSZ];
     Response_P(PSTR("{\"" D_CMND_MODULE "\":\"%s\",\"" D_JSON_VERSION "\":\"%s%s\",\"" D_JSON_FALLBACKTOPIC "\":\"%s\",\"" D_CMND_GROUPTOPIC "\":\"%s\"}"),
-      ModuleName().c_str(), my_version, my_image, GetFallbackTopic_P(stopic, CMND, ""), Settings.mqtt_grptopic);
+      ModuleName().c_str(), my_version, my_image, GetFallbackTopic_P(stopic, ""), GetGroupTopic_P(stopic2, ""));
     MqttPublishPrefixTopic_P(TELE, PSTR(D_RSLT_INFO "1"));
 #ifdef USE_WEBSERVER
     if (Settings.webserver) {