Unmarshall DynamoDB JSON

Question

Given some DynamoDB JSON via a DynamoDB NewImage stream event, how do I unmarshall it to regular JSON?

{"updated_at":{"N":"146548182"},"uuid":{"S":"foo"},"status":{"S":"new"}}

Normally I would use AWS.DynamoDB.DocumentClient, however I can't seem to find a generic Marshall/Unmarshall function.

Sidenote: Do I lose anything unmarshalling DynamoDB JSON to JSON and back again?

Answer 1

You can use the AWS.DynamoDB.Converter.unmarshall function. Calling the following will return { updated_at: 146548182, uuid: 'foo', status: 'new' }:

AWS.DynamoDB.Converter.unmarshall({
    "updated_at":{"N":"146548182"},
    "uuid":{"S":"foo"},
    "status":{"S":"new"}
})

Everything that can be modeled in DynamoDB's marshalled JSON format can be safely translated to and from JS objects.