C# data type used for Lambda that receives DocumentDB change stream event

Hi whighsmith,

looks like it's a json event.

See here:

https://docs.aws.amazon.com/lambda/latest/dg/with-documentdb.html

{
    "eventSourceArn": "arn:aws:rds:us-east-1:123456789012:cluster:canaryclusterb2a659a2-qo5tcmqkcl03",
    "events": [
        {
            "event": {
                "_id": {
                    "_data": "0163eeb6e7000000090100000009000041e1"
                },
                "clusterTime": {
                    "$timestamp": {
                        "t": 1676588775,
                        "i": 9
                    }
                },
                "documentKey": {
                    "_id": {
                        "$oid": "63eeb6e7d418cd98afb1c1d7"
                    }
                },
                "fullDocument": {
                    "_id": {
                        "$oid": "63eeb6e7d418cd98afb1c1d7"
                    },
                    "anyField": "sampleValue"
                },
                "ns": {
                    "db": "test_database",
                    "coll": "test_collection"
                },
                "operationType": "insert"
            }
        }
    ],
    "eventSource": "aws:docdb"
}

Sincerely Heiko

I went with this solution. I generated classes from the incoming JSON data, then had to update generated types to use BsonTimestamp for $timestamp and BsonBinaryData for $binary data.

public Task DocumentDbEventConsumer(object events, ILambdaContext context)
{
    var jsonString = events.ToString(); //Get JSON data
    var bsonDocument = BsonSerializer.Deserialize<BsonDocument>(jsonString); //Deserialize to BsonDocument
    var docDbEvents = BsonSerializer.Deserialize<DocumentDbEvents>(bsonDocument); //Deserialize bsonDocument to the class generated from JSON data.

There is likely already a type that can be used instead of "object", but I don't know what it is. If you know, then please post your answer here. Thanks.