Parsing an object, when part of it isn't "object-y"

General
1

Received MQTT message is converted using the JSON node and gives this output:

tele/Hetty/SENSOR : msg.payload : Object
object
  Time: "2020-06-26T20:36:58"
  DS18B20-1: object
    Id: "030197946C6B"
    Temperature: 21.6

I can extract the ID value, because it's enclosed in " ". I can't seem to extract the 'Temperature' value, it isn't enclosed in quotes...I get 'undefined' errors.

Question: how to handle the '21.6' value which is formatted differently to the other values...

2

How are you trying to access it? The fact it doesn't have quotes just means its value is a number rather than a string - it doesn't affect how to access it.

To get to the ID, you would use msg.payload["DS18B20-1"].Id.
Similarly, the Temperature is msg.payload["DS18B20-1"].Temperature.

This page in the docs describes how you can use the Debug sidebar to get the path to any message element - https://nodered.org/docs/user-guide/messages

3

I had been using the 'path' button, which helped with understanding the Object structure.

My main issue seems to have been using the switch node to select on string "DS18B20-1" - when using the string option, don't need the quotes...

I now have an output message containing just 'Id' and 'temp value'. That'll do for now!

4

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