DynamoDbPreserveEmptyObject should apply to Maps

[chrylis]

Describe the feature

The @DynamoDbPreserveEmptyObject annotation should write an empty m attribute when applied to a Map property.

Use Case

I have a DynamoDB record object with a property of type Map<String, OtherRecord> nested that I will fill in as events happen. Unfortunately, DynamoDB won't let me do a single-shot update if the nested attribute does not already exist, so I want to write an empty map attribute on record creation. Currently, even with @DynamoDbPreserveEmptyObject the Map property is omitted

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS Java SDK version used

2.28.27

JDK version used

OpenJDK 64-Bit Server VM AdoptOpenJDK-11.0.11+9 (build 11.0.11+9, mixed mode)

Operating System and version

Gentoo Linux

[Pranjalbharat]

We can do this by implementing custom Marshaler interface on map. I would like to work on it, Can you please provide me more details?
You can see this for reference : https://github.com/aws/aws-sdk-go/blob/main/service/dynamodb/dynamodbattribute/encode.go#L167

[RanVaknin]

Hi @chrylis ,

Can you please give a little more details about the case that doesn't work?

so I want to write an empty map attribute on record creation. Currently, even with @DynamoDbPreserveEmptyObject the Map property is omitted

can you please share your setup and your code as well as the expected and actual item that is being created?

Thanks,
Ran~