update

src/communication.jl

@@ -24,7 +24,7 @@ mutable struct mqttClientInstance_v1 <: mqttClientInstance
   keepalivetopic::String
   keepaliveChannel::Channel
   keepaliveCheckInterval::Integer   # second
-  lastTimeMqttConnCheck::DateTime
+  lastTimeMqttConnCheck::Union{DateTime, Nothing}
 end
 
 function mqttClientInstance_v1(
@@ -78,7 +78,7 @@ mutable struct mqttClientInstance_v2 <: mqttClientInstance
   keepalivetopic::String
   keepaliveChannel::Channel
   keepaliveCheckInterval::Integer   # second
-  lastTimeMqttConnCheck::DateTime
+  lastTimeMqttConnCheck::Union{DateTime, Nothing}
   multiMsg::String  # "single", "metadata", "datapart"
 end
 """ MQTT client v2. The difference between client v1 and v2 is v2 allows multiple 
@@ -176,7 +176,7 @@ function mqttClientInstance_v2(
     keepalivetopic,
     keepaliveChannel,
     keepaliveCheckInterval,
-    Dates.now(),
+    nothing,
     multiMsg,
   )
 
@@ -368,44 +368,6 @@ function isMqttConnectionAlive(mqttInstance::T)::Bool where {T<:mqttClientInstan
   end
   return isconnectionalive
 end
-# function isMqttConnectionAlive(mqttInstanceDict::Dict{Symbol, Any})::Bool
-  
-#   starttime = Dates.now()
-#   isconnectionalive = false
-
-#   # ditch old keepalive msg is any
-#   while isready(mqttInstanceDict[:keepaliveChannel])
-#     _ = take!(mqttInstanceDict[:keepaliveChannel])
-#   end
-
-#   msgMeta = generate_msgMeta(
-#     mqttInstanceDict[:keepalivetopic],
-#     msgPurpose= "keepalive",
-#   )
-
-#   keepaliveMsg = Dict(
-#     :msgMeta => msgMeta,
-#     :text=>"keepalive",
-#   )
-
-#   publish(mqttInstanceDict[:client], keepaliveMsg[:msgMeta][:sendTopic], 
-#           JSON3.write(keepaliveMsg))
-  
-#   timediff = 0
-#   while timediff < 5
-#     timediff = timedifference(starttime, Dates.now(), "seconds")
-#     if isready(mqttInstanceDict[:keepaliveChannel])
-#       incomingMsg = take!(mqttInstanceDict[:keepaliveChannel])
-#       if incomingMsg[:msgMeta][:msgId] == keepaliveMsg[:msgMeta][:msgId]
-#         # connection is alive
-#         isconnectionalive = true
-#         break
-#       end
-#     end
-#     sleep(1)
-#   end
-#   return isconnectionalive
-# end
 
 
 """ Check mqtt server connection, reconnect if disconnected.
@@ -439,16 +401,20 @@ function checkMqttConnection!(mqttInstance::T;
   interval = keepaliveCheckInterval !== nothing ? keepaliveCheckInterval : mqttInstance.keepaliveCheckInterval
 
   # check if mqtt connection is still up
-  intervaldiff = timedifference(mqttInstance.lastTimeMqttConnCheck, Dates.now(), "seconds")
-
-  isdisconnected = false  # flag
+  intervaldiff = 
+  if mqttInstance.lastTimeMqttConnCheck !== nothing
+    timedifference(mqttInstance.lastTimeMqttConnCheck, Dates.now(), "seconds")
+  else 
+    Inf
+  end
 
+  isreconnect = false  # this value is true if connection is disconnected
   if intervaldiff > interval
     while true
       mqttConnStatus = isMqttConnectionAlive(mqttInstance) 
       if mqttConnStatus == false
-        isdisconnected = true
-        println("mqtt connection $mqttConnStatus, Attemping to reconnect $(Dates.now())")
+        isreconnect = true
+        println("mqtt connection disconnected, attemping to reconnect $(Dates.now())")
         # use new client to reconnect instead of the previous one because I don't want to modify MQTTClient.jl yet
         mqttInstance.client, mqttInstance.connection = 
                         MakeConnection(mqttInstance.mqttBrokerAddress,
@@ -458,51 +424,19 @@ function checkMqttConnection!(mqttInstance::T;
           subscribe(mqttInstance.client, topic, mqttInstance.onMsgCallback, qos=mqttInstance.qos)
         end
         MQTTClient.subscribe(mqttInstance.client, mqttInstance.keepalivetopic, mqttInstance.onMsgCallback, qos=mqttInstance.qos)
-        sleep(30)
+        sleep(1) # wait before checking connection again 
       else 
         mqttInstance.lastTimeMqttConnCheck = Dates.now()
-        if isdisconnected
+        if isreconnect
           println("connected to mqtt broker")
         end
-        return mqttConnStatus
-        break
+        return isreconnect
       end
     end
   else
-    return nothing  # still within check interval
+    return nothing  # still within check interval, no update on connection status yet
   end
 end
-# function checkMqttConnection!(mqttInstanceDict::Dict{Symbol, Any}, interval::Integer)::Bool
-#   isreconnect = false
-
-#   # check if mqtt connection is still up
-#   intervaldiff = timedifference(mqttInstanceDict[:lastTimeMqttConnCheck], Dates.now(), "seconds")
-
-#   if intervaldiff > interval
-#     while true
-#       mqttConnStatus = isMqttConnectionAlive(mqttInstanceDict) 
-#       if mqttConnStatus == false
-#         println("Attemping to reconnect")
-#         # use new client to reconnect instead of the previous one because I don't want to modify MQTTClient.jl yet
-#         mqttInstanceDict[:client], mqttInstanceDict[:connection] = 
-#                         MakeConnection(mqttInstanceDict[:mqttServerInfo][:broker],
-#                                         mqttInstanceDict[:mqttServerInfo][:port])
-#         connect(mqttInstanceDict[:client], mqttInstanceDict[:connection])
-#         for topic in mqttInstanceDict[:subtopic]
-#           subscribe(mqttInstanceDict[:client], topic, mqttInstanceDict[:onMsgCallback], qos=QOS_1)
-#         end
-#         isreconnect = true
-#         println("reconnected")
-#       else  
-#         mqttInstanceDict[:lastTimeMqttConnCheck] = Dates.now()
-#         break
-#       end
-#     end
-#   end
-
-#   return isreconnect
-# end
-
 
 
 """ Send a message to specified MQTT topic then wait for reply.