Building a custom json with SET?

Questions
1

Hi all,

Thanks to you help yesterday, I’ve been able to build a pretty cool flow to request a Solar Measurement API at Solcast.

At the end of my workflow, I have a table with a lot of line of that kind in a nice json format:

[
{
"period_end": "2021-08-25T22:05:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-25T22:10:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-25T22:15:00.000Z",
"period": "PT5M",
"total_power": 0
}
]

But, I need to request the API with this :

{
  "measurements": [
{
"period_end": "2021-08-25T22:05:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-25T22:10:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-25T22:15:00.000Z",
"period": "PT5M",
"total_power": 0
}
]
}

Is there a way to do it without code ? Otherwise, what would be the right function to produce the right json whatever the number of line of the table ?

Thanks a lot for your help.

A feed-back that would be cool to find on the documentation, it’s how to do maths using SET node. I did find the answer on previous community question, but it would make sens to find it in documentations.

2

Next week probably we are going to release a new node called Item List Helper which is going to make uses cases like this one really easy to solve.

In the meantime, you can use a function node as shown below:

return [
  {
    json: {
      measurements: items.map(item => item.json)
    }
  }
]
Example workflow
1 Like
3

Thanks @RicardoE105, it works fine !

I will be pretty happy to test this new node.

4

Hi again,

It does not work when I request the API, I did find the issue with postman.

The function @RicardoE105 did suggest start the json with [].

So if I take an example, the expected body for the API request is :

{
"measurements": [
{
"period_end": "2021-08-26T05:25:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-26T05:30:00.000Z",
"period": "PT5M",
"total_power": 0
}
]
}

Actually, I have this format with the function :

[
{
"measurements": [
{
"period_end": "2021-08-26T05:25:00.000Z",
"period": "PT5M",
"total_power": 0
},
{
"period_end": "2021-08-26T05:30:00.000Z",
"period": "PT5M",
"total_power": 0
}
]
}
]

What should I change in the function code ? Or do to request the API with the right body ?

Thanks a lot for your help

5

Just reference the array in the HTTP node.

image
image754×450 20.1 KB

2 Likes
6

Thanks a lot @RicardoE105. I made it work !

Now I can send my PV energy produced of the day before to Solcast API to compare if their prediction as good or not.

An overview of the flow :

fronisus solcast measurements
fronisus solcast measurements3160×524 134 KB

And the result on solcast Website :

solcast fronius
solcast fronius2022×1066 152 KB

A bit of industrialization to do to make it run once a day at night and to be notified of execution error, and it will be all good.

N8N is really great ! If you achieve to enhance how to manipulate data without function, it will be amazing.

7

Hey @mcc37!

This looks amazing! We are making final changes to the new Items node which would make data transformation easy :wink:

1 Like
8

I will be happy to check this node !

1 Like