[FEATURE] Serialize DateOnly as a date instead of serializing its properties individually

[nalka0]

Is your feature request related to a problem?

DateOnly properties are treated as any other complex type and its properties are serialised individually. It prevents using features like date ranges when searching.

What solution would you like?

DateOnly properties be treated as DateTime properties, except maybe they'd use a different format (like yyyy-mm-dd)

What alternatives have you considered?

Customizing the serialization behavior myself, but I didn't find a way to do so. Also tried applying [DateAttribute] to my property but didn't seem to change anything

Do you have any additional context?

Currently DateOnly properties are serialized this way :

"dateOnlyProperty": {
    "year": 2024,
    "month": 4,
    "day": 15,
    "dayOfWeek": 1,
    "dayOfYear": 106,
    "dayNumber": 738990
},

PS : TimeOnly may have the same kind of issues

[Xtansia]

Thanks for reporting this @nalka0! Would you be interested in contributing a fix for this? It should just involve adding a JsonFormatter similar to the DateTime & co ones then registering like here. It will require adding the minimum necessary .NET version (I think 6? as I believe it's not in .netstandard2.0) as a target framework and then using #ifs to conditionally add in the formatter depending on target .NET version.

[nalka0]

@Xtansia Honnestly, I don't feel familiar enough with either OpenSearch nor this nuget package to feel like sending a pull request 😅
I also am not so familiar with the .Net version management you described but can confirm DateOnly has been introduced in .Net 6 and isn't in .Net standard

[Xtansia]

@nalka0 That's completely understandable and no problem :)

[joefeser]

I am going to attempt a PR for this one

[nalka0]

I guess this issue could be reopened (can't do it myself) based on the problems I described on the related PR #734 (comment)

[joefeser]

@nalka0 If you can reach out to me (see contact info), I can work with you to ensure everything works as expected.

[nalka0]

@nalka0 If you can reach out to me (see contact info), I can work with you to ensure everything works as expected.

I'm sorry, what contact info are you talking about ? I don't see any 😅

[joefeser]

Sorry I realized I took my email off my profile. @nalka0 joseph dot Feser at the google email service.