Insert whole json to the field in Dynamo DB using AWS Step Functions

Question

I am trying to PutItem into the DynamoDB using the AWS Step Functions.

I managed to save Item with simple string fields (S), but one of the fields should store the whole JSON payload. So it should be the Map (M).

But my payload includes nested Maps also.

Example JSON:

  {
  "firstMap": {
     "field": "something",
  },
  "secondMap": {
    "nestedMap": {
       "field": "something",
    },
    "anotherNestedMap": [
      {
        "field": "something",
        "oneMoreNestedMap": {
          "andOneMore": {
            "field": "something",
          },
          "arrayComesHere": [
            {
              "andAgainNestedMap": {
                "field": "something",
              },
              "andAgain": [
                {
                  "field": "something",
                  "alsoNestedArray": [
                    {
                       "field": "something"
                    }
                  ]
                }
              ]
            }
          ]
        },
        "letItBeFinalOne": [
          {
            "field": "something"
          }
        ]
      }
    ]
...

What I want to do is to just say, hey Step Function, insert please this whole JSON into the item field like this

"Item": {
         ...

         "whole_payload": {
           "M.$": "$"
         },

       } ...

But it fails, cause it accepts only one Map to be handled. So I need to directly iterate over all nested maps and mark them with 'M'.

Is there a way to make it resolve it by itself?

Like in Typescript I can use aws.DynamoDB.DocumentClient() and just put a whole JSON to the field and it resolves all the maps by itself

Answer 1

Came across a thread for similar request to AWS Step functions team. New feature enhanced allows something closer to what you are looking for.

Sample snippet:

...
      "Parameters": {
        "TableName" : "dynamodb-table",
        "Item":{
          "requestId" : {
            "S.$": "$.requestId"
          },
          "payload": {
            "S.$":"States.JsonToString($)"
          }
        }
...

AWS Reference