Substr in function

[bpi2008]

Hello all,

I thought I could put a substring in a function but it doesn't work a priori, what is my mistake please?

I have this error => TypeError: Data.substr is not a function

Below my (simple) function :

let Data = msg.payload;
let totalLeaks = (Data.substr(6,6));
let lastleakduration = (Data.substr(12,6));
msg.payload = {
    leaks : totalLeaks,
    duration : lastleakduration
}
return msg;

[knolleary]

Hi @bpi2008

substr is a function only available on String objects.

This error suggests the msg.payload you are passing this function is not a String.

Can you wire in a Debug node in parallel to see exactly what msg.payload you are passing into the function?

[bpi2008]

Hi Knolleray,

decoded_payload: object
BAT_V: 3.144
LAST_WATER_LEAK_DURATION: 0
MOD: 2
WATER_LEAK_STATUS: 0
WATER_LEAK_TIMES: 92

I have changed simply my function and i's ok now by :

var duration = msg.payload.uplink_message.decoded_payload.WATER_LEAK_TIMES;
msg.payload = duration;
return msg;

I'm very interesting to test "substr" for other functions.

Many thanks for all. Bernard

[Colin]

@bpi2008

I'm very interesting to test "substr" for other functions.

For the record, you should be using substring(), substr has been deprecated.

String.prototype.substr() - JavaScript | MDN

[bpi2008]

very good thanks Colin