CODEWITHSUNDEEP
dataweavemulesoft
user12445682
user12445682

Reputation: 25

flattening of nested arrays with variable depth with dwl 2.0

I have the below data:

{
  "currencyCode": "GBP",
  "type": "New",
  "orderLines": [
    {
      "currencyCode": "EUR",
      "id": "8023O000000Cc8pQAC",
      "orderLines": [
        {
          "currencyCode": "EUR",
          "id": "8023O000000Cc8qQAC",
          "parentId": "8023O000000Cc8pQAC",
          "orderLines": []
        },
        {
          "currencyCode": "EUR",
          "id": "8023O000000Cc8rQAC",
          "parentId": "8023O000000Cc8pQAC",
          "orderLines": []
        }
      ]
    },
    {
      "currencyCode": "EUR",
      "id": "8023O000000Cc8vQAC",
      "orderLines": [
        {
          "currencyCode": "EUR",
          "id": "8023O000000Cc8wQAC",
          "parentId": "8023O000000Cc8vQAC",
          "orderLines": []
        }
      ]
    }
  ]
}

Note: orderLines array could be of any depth

I want to have output like this:

{
  "currencyCode": "GBP",
  "type": "New",
  "orderLines": [
    {
      "currencyCode": "EUR",
      "id": "8023O000000Cc8pQAC",
      "orderLines": []
    },
    {
        "currencyCode": "EUR",
        "id": "8023O000000Cc8qQAC",
        "parentId": "8023O000000Cc8pQAC",
        "orderLines": []
    },
    {
        "currencyCode": "EUR",
        "id": "8023O000000Cc8rQAC",
        "parentId": "8023O000000Cc8pQAC",
        "orderLines": []
    },
    {
      "currencyCode": "EUR",
      "id": "8023O000000Cc8vQAC",
      "orderLines": []
    },  
    {
      "currencyCode": "EUR",
      "id": "8023O000000Cc8wQAC",
      "parentId": "8023O000000Cc8vQAC",
      "orderLines": []
    }
  ]
}

Upvotes: 1

Views: 332

Answers (1)

Shoki
Shoki

Reputation: 1538

You can do it with a recursive function that does the following:

  1. if there's no elements in the level returns []
  2. recursively takes the orderLines of each level (without the children field)
  3. appends the orderLines of the next level

like this:

%dw 2.0
output application/json

fun getNextLevel(orders: Array) = flatten(orders.orderLines)

fun removeChildren(orders: Array) = 
    orders map ((value) -> 
        value - "orderLines"
    )

fun getOrders(orders: Array) = do {
    orders match {
        case [] -> []
        else -> removeChildren(orders) ++ getOrders(getNextLevel(orders))
    }

}
---
{
  "currencyCode": payload.currencyCode,
  "type": payload."type",
  "orderLines": getOrders(payload.orderLines)
}

Upvotes: 3

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