I have a data class which looks like this: ```/** ...

# ktor

[Giuliopime]

I have a data class which looks like this:

/**
 * Represents a single list, which can contain categories to organize list items in it
 */
@Serializable
data class ListDto(
    @Contextual @SerialName("_id") val id: String = ObjectId().toHexString(),
    val user_id: String,
    var name: String,
    val categories: MutableList<CategoryDto>,
    // TODO: types do be defined
    var icon: String,
    var color: String
)

I want the user to create a new List from the frontend so I will need to receive the list data in my ktor put route

route("/lists") {
            get {
                // Returns all lists
            }

            put {
               // Need to receive the list data here but obviously it doesn't have an id yet
            }

The issue is that when the user wants to create a list it will not send the list id too, 'cause that will be generated on the server after receiving the list properties like name, categories, etc...
Isn't there a way to reuse the ListDto data class but fill the id variable dynamically?

[Giuliopime]

Uhm I think the = ObjectId().toHexString() already does it for the id, but that about the user_id for example

[Adam Cooper]

probably a better question for #serialization but i think the only option here is to either use a default argument or create a custom serializer

[Giuliopime]

Why the custom serializer?

[Adam Cooper]

It's just another way you could implement the logic. It's probably not the best way to do it. Another choice would be to make the property nullable

[Giuliopime]

Making it nullable would make the dev experience far worse imo

[Giuliopime]

I could just create another data class for the received data even tho that's what I wanted to avoid

[Adam Cooper]

You might find something useful in here which might make using two separate classes a little nicer https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/polymorphism.md

[Adam Cooper]

Maybe the client-side class could inherit from the server-side class and set the undesired property to @Transient

[Giuliopime]

The client-side is flutter xD

[Giuliopime]

So not possible rn

[Adam Cooper]

Ohhhh I see. I thought you were reusing the same code for client and server. I think the principle still applies if it's all on the server, just instead of client and server, it's incoming and outgoing

[Giuliopime]

Uhmm let me check that Transient

[Adam Cooper]

you could also maybe override it with a default argument in the subclass. or don't listen to me; i'm just some guy who doesn't really know what he's talking about

[Giuliopime]

Me neither