Custom Serialization can't be used because of compile-time error in RPCs.

[Dziii]

Describe the bug
RPCs with parameters that are not built in types trigger a compile time error.
This prevents us from using the custom serialization described here: https://mp-docs.dl.it.unity3d.com/docs/advanced-topics/custom-serialization

To Reproduce

1. Create an RPC with a parameter you plan to have custom serialization for.
   IE: public void ExampleServerRPC(Vector2Int v2i)
   {
   }

2. Observe that the Unity Editor returns "error - RPC method parameter does not support serialization: UnityEngine.Vector2Int"
   as a compile-time error

Expected behavior
No compile-time error. Instead, unity returns a run-time error if a non built in type isn't registered with custom serialization.

Environment (please complete the following information):

• OS: Windows 10
• Unity Version: 2020.3.1f1
• MLAPI Version: Experimental Release 0.1.0

[0xFA11]

created MTT-576 for tracking in the backlog.

[ArcadeRenegade]

Is there a workaround for this?

[0xFA11]

hey @Dziii — do you mind sharing more code snippets?
potentially the Vector2Int implementation and the class that implements ExampleServerRPC method?
a custom type that implements INetworkSerializable should just be fine, I wonder what you were trying to achieve there.

[ArcadeRenegade]

If it helps, my use case is using Protobuf to serialize complex classes. I got it working with NetworkVariable but I can't get it to work with RPCs because of the compiler error.

using System.IO;
using UnityEngine;
using MLAPI.Serialization;
using MLAPI.Serialization.Pooled;
using Models;
using Google.Protobuf;

[ExecuteInEditMode]
public class CustomSerialization : MonoBehaviour
{
	void Start()
	{
		SerializationManager.RegisterSerializationHandlers<InventoryState>(
			SerializeProtobufMessage,
			DeserializeInventoryState
		);

		SerializationManager.RegisterSerializationHandlers<EquipmentState>(
			SerializeProtobufMessage,
			DeserializeEquipmentState
		);
	}

	private void SerializeProtobufMessage<T>(Stream stream, T instance) where T : IMessage<T>
	{
		using (PooledNetworkWriter writer = PooledNetworkWriter.Get(stream))
		{
			writer.WriteByteArray(
				instance.ToByteArray()
			);
		}
	}

	private InventoryState DeserializeInventoryState(Stream stream)
	{
		return DeserializeProtobufMessage<InventoryState>(stream, InventoryState.Parser);
	}

	private EquipmentState DeserializeEquipmentState(Stream stream)
	{
		return DeserializeProtobufMessage<EquipmentState>(stream, EquipmentState.Parser);
	}

	private T DeserializeProtobufMessage<T>(Stream stream, MessageParser<T> parser) where T : IMessage<T>
	{
		using (PooledNetworkReader reader = PooledNetworkReader.Get(stream))
		{
			return parser.ParseFrom(
				reader.ReadByteArray()
			);
		}
	}
}

[TwoTenPvP]

hey @Dziii — do you mind sharing more code snippets?

potentially the Vector2Int implementation and the class that implements ExampleServerRPC method?

a custom type that implements INetworkSerializable should just be fine, I wonder what you were trying to achieve there.

https://docs.unity3d.com/ScriptReference/Vector2Int.html

My understanding is that he wants to use custom serialization handlers for the RPC.

[Dziii]

hey @Dziii — do you mind sharing more code snippets?
potentially the Vector2Int implementation and the class that implements ExampleServerRPC method?
a custom type that implements INetworkSerializable should just be fine, I wonder what you were trying to achieve there.

https://docs.unity3d.com/ScriptReference/Vector2Int.html

My understanding is that he wants to use custom serialization handlers for the RPC.

Yup, exactly. It used to work before the version 0.1.0 merge.
Based on the logging in this thread, it sounds like it has been fixed and we're just waiting for the next release?
(When could we expect it?)

For what it's worth though, this is basically the code:

public class NetworkController : NetworkBehaviour
{
    public void Start()
    {
        SerializationManager.RegisterSerializationHandlers(NetworkSerializations.SerializeVector2Int, NetworkSerializations.DeserializeVector2Int);
    }

    [ServerRpc]
    public void ExampleServerRPC(Vector2Int v2i)
    {
    }
}