JSON数组mule 4 dataweave中的迭代

Question

{
  "id": "/",
  "code": "/",
  "typeCode": "CPC",
  "timeStamp": "2021-11-16T17:00:00-06:00",
  "childList": [
    {
      "id": "577-1-1",
      "code": "1111",
      "name": "Electronics-1-1",
      "displayName": "Electronics-1-1",
      "active": true,
      "languageCode": "en",
      "typeCode": "CPC",
      "childList": [
        {
          "id": "579-2-1",
          "code": "2222",
          "name": "Calculators-2-1",
          "displayName": "Calculators-2-1",
          "active": true,
          "languageCode": "en",
          "typeCode": "CPC",
          "childList": null
        },
        {
          "id": "509-2-2",
          "code": "3333",
          "name": "Oven-2-2",
          "displayName": "Oven-2-2",
          "active": true,
          "languageCode": "en",
          "typeCode": "CPC",
          "childList": [
            {
              "id": "749-3-1",
              "code": "4444",
              "name": "MicroOven-3-1",
              "displayName": "MicroOven-3-1",
              "active": true,
              "languageCode": "en",
              "typeCode": "CPC",
              "childList": null
            }
          ]
        }
      ]
    },
    {
      "id": "549-1-2",
      "code": "5555",
      "name": "Toys, Crafts & Leisure",
      "displayName": "Toys, Crafts & Leisure",
      "active": true,
      "languageCode": "en",
      "typeCode": "CPC",
      "childList": [
        {
          "id": "49674",
          "code": "7605",
          "name": "Pet Supplies",
          "displayName": "Pet Supplies",
          "active": true,
          "languageCode": "en",
          "typeCode": "CPC",
          "childList": [
            {
              "id": "49684",
              "code": "7615",
              "name": "Beds & Houses",
              "displayName": "Beds & Houses",
              "active": true,
              "languageCode": "en",
              "typeCode": "CPC",
              "childList": [
                
              ]
            }
          ]
        }
      ]
    },
    {
      "id": "58782",
      "code": "0100",
      "name": "Fashion (new)",
      "displayName": "Fashion",
      "active": true,
      "languageCode": "en",
      "typeCode": "CPC",
      "childList": [
        {
          "id": "49056",
          "code": "6958",
          "name": "Blazers & Jackets, Etc. - Department",
          "displayName": "Blazers & Jackets, Etc.",
          "active": true,
          "languageCode": "en",
          "typeCode": "CPC",
          "childList": [
            {
              "id": "50851",
              "code": "7837",
              "name": "Dusters PDM Name",
              "displayName": "Dusters PDM Display Name",
              "active": true,
              "languageCode": "en",
              "typeCode": "CPC",
              "childList": null
            }
          ]
        }
      ]
    }
  ]
}

And the expected XML is as below - Here the categoryPath has to be noted for the complete address of childElement and has to be grouped under 1st parent childList We will not know the exact child elements of any array ie, there can be 'n' number of childList inside a childList. (When the childList value is either empty array [] or null, it is considered as no child elements of that childList.) How many elements are present in 1st childlist array - those many CategoryList elements has to be formed in xml Note: here I have just taken 2 elements as an example - but any childlist array can have any number of childlists array inside it.

XML Transformation:

<Category CategoryId="${childList.code}" CategoryPath="${childList.code}/${childList.childList.code}" Description="${childList.displayName}" ShortDescription="${childList.name}">
    <Extn ExtnSyncTS="${headers.timeStamp}"/>
</Category>

Expected XML:

<CategoryListArray>
<CategoryList>
    <Category CategoryId="1111" CategoryPath="/DefaultText/1111" Description="Electronics-1-1" ShortDescription="Electronics-1-1">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="2222" CategoryPath="/DefaultText/1111/2222" Description="Calculators-2-1" ShortDescription="Calculators-2-1">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="3333" CategoryPath="/DefaultText/1111/3333" Description="Oven-2-2" ShortDescription="Oven-2-2">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="4444" CategoryPath="/DefaultText/1111/3333/4444" Description="MicroOven-3-1" ShortDescription="MicroOven-3-1">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
</CategoryList>
<CategoryList>
    <Category CategoryId="5555" CategoryPath="/DefaultText/5555" Description="Toys, Crafts & Leisure" ShortDescription="Toys, Crafts & Leisure">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="7605" CategoryPath="/DefaultText/5555/7605" Description="Pet Supplies" ShortDescription="Pet Supplies">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="7615" CategoryPath="/DefaultText/5555/7605/7615" Description="Beds & Houses" ShortDescription="Beds & Houses">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
</CategoryList>
<CategoryList>
    <Category CategoryId="0100" CategoryPath="/DefaultText/0100" Description="Fashion" ShortDescription="Fashion (new)">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="6958" CategoryPath="/DefaultText/0100/6958" Description="Blazers & Jackets, Etc." ShortDescription="Blazers & Jackets, Etc. - Department">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
    <Category CategoryId="7837" CategoryPath="/DefaultText/0100/6958/7837" Description="Dusters PDM Display Name" ShortDescription="Dusters PDM Name">
        <Extn ExtnSyncTS="2021-11-16T17:00:00-06:00"/>
    </Category>
</CategoryList>
</CategoryListArray>

Answer 1

I have created a solution using recursion. It might be a bit confusing, I have put explanation in comments within the DW.

%dw 2.0
var extnSyncTs = payload.timeStamp

// This is just a small utility function to generate the "CategoryPath"
fun appendToPath(currentPath, pathToAppend) = 
    if(isEmpty(currentPath)) pathToAppend
    else currentPath ++ "/" ++ pathToAppend

/*
* This function will take one object from the child list array 
* and return corresponding XML Category object  
*/
fun childListElementToCategory(childListElement, rootPath='') = 
    {
        Category @(
            CategoryId: childListElement.code,
            CategoryPath: rootPath appendToPath childListElement.code,
            Description: childListElement.displayName,
            ShortDescription: childListElement.name
        ): {
            Extn @(ExtnSyncTS: extnSyncTs): null
        }
    }

/**
* This is a tricky one. It accepts the childList array then uses the above
* function to get the Category element for each of the chileList element. It 
* uses recurssion to call itself if there are more childList in any element 
* of the passed childList. The rootPath element is to retain the path from 
* the parent childList element. 
*/

fun childListToCategoryList(childList, rootPath='') = 
    childList map ((childListElement) -> 
        {
            (childListElementToCategory(childListElement, rootPath)),
            (childListToCategoryList(childListElement.childList, rootPath appendToPath childListElement.code)) 
        }
    )
output application/xml
---
CategoryListArray: {
    CategoryList: (childListToCategoryList(payload.childList))
}