Dataweave 1.0 Add Items to Array

Question

My sample payload is given below:

{
  "ID": "72a6dcc0",
  "SourceCode": "ABC",
  "TargetCode": "DEF",
  .
  .
  .
  .
  .
  "Products": [
    {
      "ProdId": "410ef294",
      "ProdDetails": {
        "ProdIdentifier": "410ef294-e80b",
        "DateFrom": "2019-01-01T00:00:00Z",
        "DateTo": "9999-12-31T00:00:00Z",
        "ProductName": "ProdA"
      }
    }
  ]
}

I need to add a new attribute called "ProdDescription" to the "Products" array so that my output looks like this:

{
  "ID": "72a6dcc0",
  "SourceCode": "ABC",
  "TargetCode": "DEF",
  .
  .
  .
  .
  .
  "Products": [
    {
      "ProdId": "410ef294",
      "ProdDetails": {
        "ProdIdentifier": "410ef294-e80b",
        "DateFrom": "2019-01-01T00:00:00Z",
        "DateTo": "9999-12-31T00:00:00Z",
        "ProductName": "ProdA",
        "ProdDescription": "This is a Sample"
      }
    }
  ]
}

The payload that I have given is only a sample and it has hundreds of attributes. I only need to add a new attributes to the "Products" array and also retain the other items in the main payload. Is it possible to do a complete payload "map" and inside add a new attribute to an array using "mapobject"? I am on dataweave 1.0

machaval · Answer 1 · 2020-04-13T13:46:01.277

2

The simplest way to do this is by removing the "Product" entry using the "-" operator and later adding the new "Product" entry using "++" to append a new element into an array use the "+" operator

So what I did is a helper function that express the intention of updating a field value. This function has 3 params First the object to update, second the field name, and third a callback that is going to provide the new value and is being called with the old value.

This is my sample code

%dw 1.0
%input payload application/json
%output application/json

%function updateWith( value,fieldName, newValueProvider) 
  using(oldValue = value[fieldName]) (
    (value - fieldName) ++ {(fieldName): newValueProvider(oldValue)}
  )



---
updateWith(payload, "Products", 
  (products) -> (
    {
      "Products": products map ((item) -> 
          updateWith(item, "ProdDetails", 
              ((ProdDetails) -> ProdDetails ++ {"ProdDescription": "This my new Product"})))
    }
  )
)

edited Apr 13 '20 at 13:46

answered Apr 13 '20 at 11:56

machaval

4,969
14
20

Thank you for answering. If I were to add a new attribute under the first product itself, will this work? I think you have given an example to add a new product itself. – Triumph Spitfire Apr 13 '20 at 12:13
I am trying something like this: payload - "Products" ++ ( { Products: payload.Products + ("ProdDescription": "This is a Sample") } ) However not getting the desired output – Triumph Spitfire Apr 13 '20 at 12:21
1

I have updated with a new snippet that does what you requested – machaval Apr 13 '20 at 13:47
1

Thank you very much for this. Using your previous approach, I was able to achieve this using mapobject: payload - "Products" ++ ( (Products: payload.Products mapObject {($$): $} ++ {"ProdDescription": "This is a Sample"} ) ) – Triumph Spitfire Apr 13 '20 at 18:34

Dataweave 1.0 Add Items to Array

1 Answers1