$apply is not returning the response with OData annotations

[rbalagangadharan]

Hi All,

$apply=aggregate or groupby returns only JSON payload in response without ODATA annotations. There is no ODATA headers in response as well.

Request:
apply=groupby((FieldProductionsId,FieldCode),aggregate(DaysOnProduction with sum as SumOfProd))

Response Body:

[
    {
        "FieldCode": 659,
        "FieldProductionsId": 2,
        "SumOfProd": 28
    }
]

In above the response is pure JSON not with OData annotations.

How to make the response with OData annotations, I can use the customized middleware like this, but we need to again write more logic for other OData annotations, like count, etag etc.

When we give request with http://localhost:64771/v1/Customers?$apply=aggregate(Id with sum as TotalCount)
the outputFormatter in below screen shot is coming as {Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonOutputFormatter}

where as without apply http://localhost:64771/v1/Customers?$select=Name the outputFormatter is set to {Microsoft.AspNetCore.OData.Formatter.ODataOutputFormatter}.

I presume that these different makes apply to not set the OData annotations for apply.

Thanks in advance.