one key dictionary comparison added

example_config/config.py

 MQTT_SERVER = "host"
 
 TOPIC = 'topic'
-PAYLOAD = b'payload'
+PAYLOAD_KEY = 'key'             # Give a key or None to compare plain DATA
+PAYLOAD_DATA = 'data'           # Give data to compare or None if no comparison is needed
+
 COMMAND = "aplay %s/ring.wav -D plughw:UACDemoV10,0" % __BASEPATH__
 
 #

exec_command.py

 import config
+import json
 import logging
 import mqtt
 import os
 
     def mqtt_rx(self, client, userdate, message):
         if not self.__block_execution__:
-            if message.payload == config.PAYLOAD:
+            data = None
+            if config.PAYLOAD_KEY is None:
+                try:
+                    data = message.payload.decode('utf-8')
+                except:
+                    logger.exception("Error decoding mqtt message")
+            else:
+                try:
+                    payload = json.loads(message.payload)
+                except:
+                    logger.exception("Error decoding json mqtt message")
+                else:
+                    data = payload.get(config.PAYLOAD_KEY)
+            if config.PAYLOAD_DATA is None or data == config.PAYLOAD_DATA:
                 logger.debug("Starting execution in background...")
                 self.__block_execution__ = True
                 self.enqueue(5, self.exec_command)