Parse aws dynamo events.DynamoDBAttributeValue to Struct

main.go

func UnmarshalEvent(attribute map[string]events.DynamoDBAttributeValue, out interface{}) error {
  dbAttrMap := make(map[string]*dynamodb.AttributeValue)
  for k, v := range attribute {
    var dbAttr dynamodb.AttributeValue
    bytes, marshalErr := v.MarshalJSON()
    if marshalErr != nil {
      return marshalErr
    }
    if err := json.Unmarshal(bytes, &dbAttr); err != nil {
      return errors.WithMessage(err, fmt.Sprintf("can't umarshal: %s", attribute))
    }
    dbAttrMap[k] = &dbAttr
  }
  return dynamodbattribute.UnmarshalMap(dbAttrMap, out)
}

func main(){
  var compositionEvent events.DynamoDBAttributeValue
  var composition []SomeStruct
  switch compositionEvent.DataType() {
  case events.DataTypeString:
    compositionJson := compositionEvent.String()
    if err := json.Unmarshal([]byte(compositionJson), &composition); err == nil {
      return &composition
    } else {
      panic(errors.WithMessage(err, fmt.Sprintf("can't parse composition: %s, event=%s", compositionJson, compositionEvent)))
    }
  case events.DataTypeList:
    for _, v := range compositionEvent.List() {
      c := new(SomeStruct)
      fmt.Println(UnmarshalEvent(v.Map(), &c))
    }
  } 
}

https://intellipaat.com/community/16713/unmarshal-map-string-dynamodbattributevalue-into-a-struct