kotlinx-serialization-json/kotlinx.serialization.json/JsonEncoder/encodeJsonElement

encodeJsonElement

abstract fun encodeJsonElement(element: JsonElement)(source)

Appends the given JSON element to the current output. This method is allowed to invoke only as the part of the whole serialization process of the class, calling this method after invoking beginStructure or any encode* method will lead to unspecified behaviour and may produce an invalid JSON result. For example:

class Holder(val value: Int, val list: List<Int>())

// Holder serialize method
fun serialize(encoder: Encoder, value: Holder) {
    // Completely okay, the whole Holder object is read
    val jsonObject = JsonObject(...) // build a JsonObject from Holder
    (encoder as JsonEncoder).encodeJsonElement(jsonObject) // Write it
}

// Incorrect Holder serialize method
fun serialize(encoder: Encoder, value: Holder) {
    val composite = encoder.beginStructure(descriptor)
    composite.encodeSerializableElement(descriptor, 0, Int.serializer(), value.value)
    val array = JsonArray(value.list)
    // Incorrect, encoder is already in an intermediate state after encodeSerializableElement
    (composite as JsonEncoder).encodeJsonElement(array)
    composite.endStructure(descriptor)
    // ...
}