Trying to convert mqtt output to input into influxdb

[phkul]

Hello,

i need your help with converting mqtt outputs.
I have a bunch of "mqtt in" nodes to recieve messages from a mqtt server.
These messages are sturctured like this:

The payload of these messages need to look like this:

...so they can be input correctly into influxdb.

How can I achieve the obove?

Thank you for your help!

[jbudd]

Hi @phkul.

If your payload is a string with spaces between the elements, you could use a function like this

let myarray = msg.payload.split(" ");
msg.payload = {
    "name": myarray[0],
    "value": myarray[1].split("=")[1],
    "time": myarray[2],
}
return msg;

Edit @bakman2 remembered to convert the value to a number
You may need to convert the date/time too?
And we both assumed that your "vaule" was a typo.

[bakman2]

You could use a function node to split the string;

// msg.payload input =  "something_german value=192.00 1234567890000"

let m = msg.payload.split(" ")
let name = m[0].trim()
let value = m[1].split("=")[1]
let time = m[2].trim()

msg.payload = {name,value:parseFloat(value),time}

return msg;

output:

msg.payload : Object
object
name: "something_german"
value: 192
time: "1234567890000"

edit @jbudd typed a bit quicker

[ScheepersJohan]

@phkul

i need your help with converting mqtt outputs.

Most of the time it is easier to get the sending device to format the JSON correctly, than to use some fancy foot work in Node-red to fix it.

Just a note, I know sometimes it is not possible.

[phkul]

@jbudd @bakman2 thank you so much for your help. Your solutions solved my problem perfectly!