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 machaval · Accepted Answer · 2020-04-13T11:56:51

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"})))
    }
  )
)

Dataweave 1.0 Add Items to Array

1 Answers