openweather plugin ?

[Buxton]

@akbooer I think I found the culprit causing the random connection disconnects to Mosquitto. The LWT payload for a given device is a simple string, which doesn't seem to decode in the json decode call. So I added the below code to send a json string to the decoder. The errors have disappeared and I now see the LWT variable in the service variables. The variable reads "LWT : Online"

--line 165
local valid = {SENSOR = true, STATE = true, RESULT = true, LWT = true}

--line 172
  -- begin code
  local info, err = json.decode (message)
   
  if message then
	if not info then  -- json did not decode because of single string parameter
		message = '{' .. '"' .. mtype .. '"' .. ':' .. '"' .. message .. '"' .. '}'
	end
  end
  -- end code

  
  local info, err = json.decode (message)  

This is probably not the way you would handle the error, but it does work.

[akbooer]

@buxton

Great work!

There may be some compatibility problem betwen JSON decoders – which one are you using (openLuup / Cjson / RapidJson) ? The beginning of the Startup Log should tell you...

2021-06-06 20:08:48.470   openLuup.json::        version RapidJSON (0.6.1) + openLuup (2021.05.01)  @akbooer

[akbooer]

@buxton

Should now be fixed in development v21.6.8.

My implementation, FYI:

  local tasmota, mtype = tasmotas: match "^(.-)/(%u+)"
  local valid do            -- thanks @Buxton for LWT as text message
    local j, t = "json", "text"
    valid = {SENSOR = j, STATE = j, RESULT = j, LWT = t} 
  end
  
  local decoder = valid[mtype]
  if not (tasmota and decoder) then 
    _log (table.concat ({"Topic ignored", topic, message}, " : "))
    return 
  end
  
  local info, err
  if decoder == "text" then
    info = {[mtype] = message}
  else
    info, err = json.decode (message)
    if not info then 
      _log ("JSON error: " .. (err or '?')) 
      _log ("Received message ignored: " .. message)
      return 
    end
  end

[Buxton]

@akbooer I used openluup json. I tried dkjson, but there was no change in effect.

[Buxton]

@akbooer Yes, that should work. However, the LWT MQTT specification calls for a standard message, so a tasmota upgrade could change the text message to a json message. Is there a way to test the message for a non-json string, and then filter accordingly. I fear the hardcoded flags will inevitably break....

[akbooer]

Yes, I thought of doing it that way. A simple check for a leading [ or { should be adequate.

This is the one thing I don’t like about Tasmota (as mentioned a while ago) … no real standards.

[akbooer]

OK, so here's what it will be now, a hybrid of our approaches...

  local valid = {SENSOR = 1, STATE = 1, RESULT = 1, LWT = 1}    -- thanks @Buxton for LWT as text message
  
  if not (tasmota and valid[mtype]) then 
    _log (table.concat ({"Topic ignored", topic, message}, " : "))
    return 
  end
  
  local info = json.decode (message) or {[mtype] = message}   -- treat invalid JSON as plain text

[Buxton]

@akbooer Awesome. Cool lua magic using the exception return with "or". That should cover all text messages that are topic filtered.

[Buxton]

@akbooer Can I ask you for one more addition. I'd like to be able to set tasmota prefixes and suffixes via lua startup. Something like:

attr ("openLuup.Tasmota.Prefix", "tele", "tasmota/tele","stat")
attr ("openLuup.Tasmota.Topic", "SENSOR", "STATE","RESULT", "LWT")

You'd also need to change the upper case error check on the topic as some of the full topic suffixes are not all in upper case:

local tasmota, mtype = tasmotas: match "^(.-)/(.+)"

[akbooer]

@buxton said in openLuup: Tasmota MQTT Bridge:

I'd like to be able to set tasmota prefixes and suffixes via lua startup.

Try the latest development version (21.6.12b)

A tiny syntax difference from your suggestion, you need to write...

attr ("openLuup.Tasmota.Prefix", {"tele", "tasmota/tele", "stat"})
attr ("openLuup.Tasmota.Topic",  {"SENSOR", "STATE", "RESULT", "LWT"})

[Buxton]

@akbooer After updating to the lastest development version (21.6.12b), I did a direct copy and paste of the above attr code into startup lua, and it appears that openLuup hangs on the ipairs iteration, because the ipairs statement is seeing a string instead of a table. I was then able to boot openLuup by removing the "or" clause :

--local prefixes = config.Prefix or {"tele", "tasmota/tele"}       -- subscribed Tasmota prefixes
  local prefixes = {"tele", "tasmota/tele"}       -- subscribed Tasmota prefixes
  for _, prefix in ipairs (prefixes) do
    luup.register_handler ("Tasmota_MQTT_Handler", "mqtt:" .. prefix .. "/#", prefix)   -- * * * MQTT wildcard subscription * * *
  end

The topic table has the same problem.

I was able to see the error message when using "./openLuup_reload" at the linux command prompt.

[akbooer]

Oh yes, that's the traditional Vera-compliant Luup API for you, which only allows string attributes.
TBH, I don't use that much these days. Sorry about that.

Two ways forward:

1. This will work right now:

local oL = luup.attr_get "openLuup"
oL.Tasmota = {
    Prefix = {"tele", "tasmota/tele", "stat"},
    Topic = {"SENSOR", "STATE", "RESULT", "LWT"}}

2. I could change the Tasmota code to accept:

attr ("openLuup.Tasmota.Prefix", "tele, tasmota/tele, stat")
attr ("openLuup.Tasmota.Topic",  "SENSOR, STATE, RESULT, LWT")

which might be better in the long run.

[Buxton]

@akbooer I'm good as I don't have additional topics that must be added at the moment. So the code change is probably the way to go.