Android Room - insert list of sealed classes .. or anything

Question

I have a list of items like the below that I would like to enter into a database using room.

 data class MyRotasDayItem(
 @PrimaryKey
 @SerializedName("id")
 val id: Long,
 @SerializedName("date")
 val date: String,
 @Embedded
 @SerializedName("dayEvents")
 val dayEvents: List<SealedObj>
 )

However I cant seem to add dayEvents. Even if I made the type List I get... Entities and POJOs must have a usable public constructor Do i have to use a type converter?

What if in the list Type is a Sealed class that contain other data objects like...

sealed class MySealedExample(
    open val foo: Long,
    open val bar: Long
) {

    @PrimaryKey(autoGenerate = true)
    var id: Int = 0


    @Entity
    data class AnExample1(
        @Ignore override val foo: Long,
        @Ignore override val bar: Long,
        val something:String
    ) : MySealedExample(foo, bar)

    @Entity
    data class AnExample2(
        @Ignore override val foo: Long,
        @Ignore override val bar: Long,
        val somethingElse:List<SomeObj>
    ) : MySealedExample(foo, bar)
}

Anyway to insert that into the database?

Thankyou

Answer 1

Use type converters, I ran into a similar problem and fixed it using type converters. To convert sealed classes into string and vice versa, I used Gson extension from this gist.

@JvmStatic
@TypeConverter
fun sealedClassToString(sealedClass: SealedClass) : String = GsonExtension.toJson(sealedClass)

@JvmStatic
@TypeConverter
fun sealedClassFromString(sealedClass: String) : SealedClass = sealedClass.let { GsonExtension.fromJson(it) }