How do I pass around java objects without using them ?

[bananasmoothii]

I have a java class Player that I want to store in js variables and pass in intercepted functions but without using properties or functions directly on Player. Do I still have to use JavetProxyConverter ?

[caoccao]

Good question. No, you don't have to. There are many ways of doing so. Here is an example.

1. Declare a static Map<Integer, Player> map.
2. Generate an unique Integer key per Player and put them to the map.
3. Pass the key to V8.
4. Get the key from the V8 function and get the Player by the key.

[caoccao]

Could you try List<Player> at both side?

[bananasmoothii]

It didn't work. Here are my functions:

@Suppress("unused")
object MinecraftJSFuns {
    @V8Function
    fun getAllPlayers(): List<Player> = Bukkit.getOnlinePlayers().toList()

    @V8Function
    fun sendMiniMessage(players: List<Player>, message: String) {
        players.forEach {
            it msg message
        }
    }
}

registered like this

val v8Runtime: V8Runtime = V8Host.getV8Instance().createV8Runtime<V8Runtime>().apply {
        createV8ValueObject().use {
            globalObject.set("mc", it)
            it.bind(MinecraftJSFuns)
        }
    }

(If you don't know kotlin, basically the createV8ValueObject is on the returned value of createV8Runtime, and here use is the same as try (var it = v8Runtime.createV8ValueObject()) { ... }, and MinecraftJSFuns is directly a class instance. The = in getAllPlayers is a shortcut for brackets and return)

The code is basically just

mc.sendMiniMessage(mc.getAllPlayers(), "hello")

But I still get a List with null elements in sendMiniMessage.

However, this does get fixed when using JavetProxyConverter().

[caoccao]

So, it works, right?

[bananasmoothii]

Yes, but not without converting all objects.
I just hope this won't have too much of a performance impact

[caoccao]

You are welcome profiling that. The performance impact is subtle.