Cant Add a own value Number to an Object Payload

General
1

Hi,

i have a Problem to add in a function Node to a Msg.Payload (is an Object) a normal value like a Number.

Its to add the Total Watthours from an old Inverter to the New Inverters Value:

var time = new Date();
var totalkwh = msg.payload["opendtu/12123/0/yieldtotal"];
var field1 = "totalkwh";


var totalkwhnew = totalkwh+1544;
msg.params = [time, totalkwhnew, field1];

return msg;

The 1544 are not added but why ?

2

You are not putting 1544 into msg.payload

Have you set the debug to output the complete message?

What do you see in debug panel if you change code to this:

var time = new Date();
var totalkwh = msg.payload["opendtu/12123/0/yieldtotal"];
var field1 = "totalkwh";
var totalkwhnew = totalkwh+1544;

msg.params = [time, totalkwhnew, field1];

msg.warn({ totalkwh, totalkwhnew, payload: msg.payload, params: msg.params })

return msg;
3

Try this...

var time = new Date();

var totalkwh = Number(msg.payload["opendtu/12123/0/yieldtotal"]);

if (isNaN(totalkwh)) {
    node.error("yieldtotal is not a number");
    return null;
}

var field1 = "totalkwh";
var totalkwhnew = totalkwh + 1544;

msg.params = [time, totalkwhnew, field1];

return msg;
4

It appears to bypass the function node without effect.

I think it's a problem with the join node before the function node

5

Post deleted

6

Maybe we need to check the value of msg.payload["opendtu/12123/0/yieldtotal"]

@dynamicdave put in a check that exits if it is not a number. (NaN)

So if it isn't a number, it will just exit.

Are you seeing/getting the node.error("yieldtotal is not a number"); message?

7

Yes i get this if i set the Join Node to Array or String, if i set the Join Node (before the Function Node) to "a key /value Object " with msg.topic as the key then it bypass the function Node and i dont see the node.error("yieldtotal is not a number");

8

Show us the message going into the function node

9

I post the complete JSON:

[
    {
        "id": "e181ab23ca2013dc",
        "type": "tab",
        "label": "Flow 1",
        "disabled": false,
        "info": "",
        "env": []
    },
    {
        "id": "a51b2b36cf83199b",
        "type": "mqtt in",
        "z": "e181ab23ca2013dc",
        "name": "",
        "topic": "opendtu/12123/0/yieldtotal",
        "qos": "0",
        "datatype": "json",
        "broker": "722c90e4f8ec0db9",
        "nl": false,
        "rap": true,
        "rh": 0,
        "inputs": 0,
        "x": 270,
        "y": 260,
        "wires": [
            [
                "0184268473772f5f"
            ]
        ]
    },
    {
        "id": "0184268473772f5f",
        "type": "join",
        "z": "e181ab23ca2013dc",
        "name": "",
        "mode": "custom",
        "build": "object",
        "property": "payload",
        "propertyType": "msg",
        "key": "topic",
        "joiner": "\\n",
        "joinerType": "str",
        "useparts": true,
        "accumulate": false,
        "timeout": "",
        "count": "1",
        "reduceRight": false,
        "reduceExp": "",
        "reduceInit": "",
        "reduceInitType": "",
        "reduceFixup": "",
        "x": 630,
        "y": 240,
        "wires": [
            [
                "d185134d62647599"
            ]
        ]
    },
    {
        "id": "d185134d62647599",
        "type": "function",
        "z": "e181ab23ca2013dc",
        "name": "function 2",
        "func": "var time = new Date();\n\nvar totalkwh = Number(msg.payload[\"opendtu/12123/0/yieldtotal\"]);\n\nif (isNaN(totalkwh)) {\n    node.error(\"yieldtotal is not a number\");\n    return null;\n}\n\nvar field1 = \"totalkwh\";\nvar totalkwhnew = totalkwh + 1544;\n\nmsg.params = [time, totalkwhnew, field1];\n\nreturn msg;",
        "outputs": 1,
        "timeout": 0,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 860,
        "y": 260,
        "wires": [
            [
                "20ebe008a74ff4f5"
            ]
        ]
    },
    {
        "id": "20ebe008a74ff4f5",
        "type": "debug",
        "z": "e181ab23ca2013dc",
        "name": "debug 2",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 1140,
        "y": 260,
        "wires": []
    },
    {
        "id": "722c90e4f8ec0db9",
        "type": "mqtt-broker",
        "name": "Mqtt Server",
        "broker": "mosquitto",
        "port": "1883",
        "clientid": "",
        "autoConnect": true,
        "usetls": false,
        "protocolVersion": "5",
        "keepalive": "60",
        "cleansession": true,
        "autoUnsubscribe": true,
        "birthTopic": "",
        "birthQos": "0",
        "birthPayload": "",
        "birthMsg": {},
        "closeTopic": "",
        "closeQos": "0",
        "closePayload": "",
        "closeMsg": {},
        "willTopic": "",
        "willQos": "0",
        "willPayload": "",
        "willMsg": {},
        "userProps": "",
        "sessionExpiry": ""
    }
]

Frist Message is from MQTT to Join Node to Function Node to Debug

10

Edit: Shrug

11

As @Steve-Mcl has mentioned, set the debug to show complete message object, as the result of your addition is in msg.params.

or if you want the result in msg.payload
change

msg.params = \[time, totalkwhnew, field1\];

to

msg.payload = [time, totalkwhnew, field1];
12

This works, but how to insert this into Postgresql ?

My Postgres Node is as follows:

INSERT INTO solar (time, field1) VALUES ($1, $2),($1, $2);

Heres explained only with msg.params

13

It works with msg.params i just didnt see it because i had a debug node with msg.payload

In the Database its all fine !

14

Just saying ^ :sweat_smile:

15

From my experience setting debug to show entire msg is nr1 most important thing when dragging a new debug node into a flow. Ideally I'll copy an existing one instead to get it configured correctly automatically.

16

See this PR already merged into v5 to set default the way you want it.

17

Glorious!