ForEach Aggregation

Question

I am using For-Each Processor. As a part of this i need to aggregate the responses of each iteration. For doing this i am using the below expression:

Step 1: Create a flowVar with name 'aggregator' with value '#[[]]'. This is initialised before For-Each Step2: In For-Each Processor once the processing is done. I use the following expression to aggregate: '#[flowVars.aggregation.add(message.payload)]'.

The Payload i get in each iteration is

[{
"Transactions": [
  {
    "Id": "",
    "CompanyId": "123",
    "ContractId": "777"
  },
  {
    "Id": "",
    "CompanyId": "123",
    "ContractId": "777"
  }
]

The result of aggregation is :

[{  
"Transactions": [
{
  "Id": "",
  "CompanyId": "123",
  "ContractId": "777"
},
{
  "Id": "",
  "CompanyId": "123",
  "ContractId": "777"
}
]
}, {
"Transactions": [
{
  "Id": "",
  "CompanyId": "555",
  "ContractId": "2345"
},
{
  "Id": "",
  "CompanyId": "7777",
  "ContractId": "2389"
}
  ]
}]

I want to merge data in single "Transactions" as a JSON Output. I am unable to achieve this.

Answer 1

Keeping with your current approach you could add the below dataweave after the aggregation:

%dw 1.0
%output application/json
---
{
    Transactions: flatten payload.Transactions
}

If the input to this transform is the output of your aggregation that you described in your question, the output is:

{
  "Transactions": [
    {
      "Id": "",
      "CompanyId": "123",
      "ContractId": "777"
    },
    {
      "Id": "",
      "CompanyId": "123",
      "ContractId": "777"
    },
    {
      "Id": "",
      "CompanyId": "555",
      "ContractId": "2345"
    },
    {
      "Id": "",
      "CompanyId": "7777",
      "ContractId": "2389"
    }
  ]
}