I’m thinking about something like this: ``` class ...

# ktor

[orangy]

I’m thinking about something like this:

class FlashSessionTransport(private val transport: SessionTransport) : SessionTransport {
    companion object {
        private val flashSessionKey = AttributeKey<Boolean>("FlashSessionReceived")
    }

    override fun receive(call: ApplicationCall): String? = transport.receive(call)?.also {
        call.attributes.put(flashSessionKey, true)
    }

    override fun send(call: ApplicationCall, value: String) = if (call.attributes.getOrNull(flashSessionKey) == true)
        transport.clear(call)
    else
        transport.send(call, value)

    override fun clear(call: ApplicationCall) = transport.clear(call)

}

inline fun <S : Any> Sessions.Configuration.flash(name: String, sessionType: KClass<S>, block: CookieSessionBuilder<S>.() -> Unit) {
    val builder = CookieSessionBuilder(sessionType).apply(block)
    val transport = FlashSessionTransport(SessionTransportCookie(name, builder.cookie, builder.transformers))
    val tracker = SessionTrackerByValue(sessionType, builder.serializer)
    val provider = SessionProvider(name, sessionType, transport, tracker)
    register(provider)
}