Line Chart with 2 lines

Dashboard
1

Hello! Newbie here, starting to learn Node-Red.
I've been wrestling with this for more than 2 weeks, being on and off, when time allows.
I have a database, in which I make a query, and get results for temperature and humidity.
These came from sensors with MQTT.
Example of my query results:
{"timestamp":"2020-06-08T21:32:59.000Z","data":"22.60","topic":"abrigo/temp"},{"timestamp":"2020-06-08T21:32:59.000Z","data":"63.00","topic":"abrigo/humi"}

I tried several ways to make this data good for a 2 line char, one for "abrigo/temp", one for "abrigo/humi".

I feel I'm close with my new approach but I cannot advance so I am asking for help.

This is my actual setup in a function to get the data prepared:

var msg1 = {};
let dataH =[];
let dataT =[];
msg1.topic = "Temp/Humi";
for (let X in msg.payload) 
{
    if (msg.payload[X].topic == "abrigo/humi")
    {
        dataH.push({"x":msg.payload[X].timestamp, "y":msg.payload[X].data});
    }
    else
    {
        dataT.push({"x":msg.payload[X].timestamp, "y":msg.payload[X].data});
    }
}
msg1.payload = [{"series":["Humidade", "Temperatura"], "data":[[dataH],[dataT]],"labels": ["Humidade","Temperatura"]}];
return (msg1);

The result from this function is this:

{
   "series":[
      "Humidade",
      "Temperatura"
   ],
   "data":[
      [
         [
            {
               "x":"2020-06-08T21:32:59.000Z",
               "y":"63.00"
            },
            {
               "x":"2020-06-08T21:33:59.000Z",
               "y":"56.00"
            },
            {
               "x":"2020-06-08T21:47:08.000Z",
               "y":"49.00"
            },
            {
               "x":"2020-06-08T21:57:08.000Z",
               "y":"53.00"
            },
            {
               "x":"2020-06-08T22:07:08.000Z",
               "y":"53.00"
            }
         ]
      ],
      [
         [
            {
               "x":"2020-06-08T21:32:59.000Z",
               "y":"22.60"
            },
            {
               "x":"2020-06-08T21:33:59.000Z",
               "y":"24.70"
            },
            {
               "x":"2020-06-08T21:47:08.000Z",
               "y":"25.20"
            },
            {
               "x":"2020-06-08T21:57:08.000Z",
               "y":"23.20"
            },
            {
               "x":"2020-06-08T22:07:08.000Z",
               "y":"23.20"
            },
            {
               "x":"2020-06-08T22:17:08.000Z",
               "y":"23.10"
            }
         ]
      ]
   ],
   "labels":[
      "Humidade",
      "Temperatura"
   ]
}

But his does not get me a 2 line graphic.

Can someone help me to understand what is wrong here?

Thank you in advance!

2

hi and welcome to the forum, I'm certain someone will be able to help you out.

Firstly though, please always wrap code in three back ticks

```
like this
```

otherwise the forum messes up your code and it is both unreadable and actually unusable.

Please edit your 1st post.

3

I'm sorry for the mistake, and thank you.

4

no worries - I edited the 2nd code block for you - much more readable for someone to assist right?

5

Yes, much more! :sweat_smile:
Thank you

6

If you look at the example in https://github.com/node-red/node-red-dashboard/blob/master/Charts.md you will see you have too many levels of array nesting in data.
dataH and dataT are already arrays, so try

msg1.payload = [{"series":["Humidade", "Temperatura"], "data":[dataH,dataT],"labels": ["Humidade","Temperatura"]}];
1 Like
7

OMG!!! It was that simple... :crazy_face: :crazy_face: Shame on me!!! :grinning:
I tried so many variants...
Thanks!!!

8

By the way, it is generally good practice to modify the existing message and pass that on rather than making a new one. You could do that by removing the creation of msg1 and the setting of its topic at the top and replace the last lines with

msg.topic = "Temp/Humi"
msg.payload = [{"series":["Humidade", "Temperatura"], "data":[[dataH],[dataT]],"labels": ["Humidade","Temperatura"]}];
return (msg);
9

Thank you for sharing. I'm starting and I will take that into account next time, also I will change my actual project with this tip.

10

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