[1.18.1] Syncing Fluid Capability in BlockEntity [Solved]

[reasure]

I have created a fluid capability on the block entity. Now I want to display this liquid in the GUI. (Type and amount of liquid) But I have no idea how to synchronize this capability in container or screen.

Edited February 28, 2022 by reasure
solved! thanks for helping!

[Luis_ST]

there are two ways:

1. you use a custom Network Packet and sync the data via a SimpleChannel (doc). whenever the data changes
2. override BlockEntity#getUpdateTag and retrun a CompoundTag with the data to sync,
   override BlockEntity#handleUpdateTag to handle the data sync on client. whenever the data changes
   you need to call BlockEntity#setChanged

choose the way you prefer

Edited February 23, 2022 by Luis_ST

[reasure]

14 hours ago, Luis_ST said:

there are two ways:

1. you use a custom Network Packet and sync the data via a SimpleChannel (doc). whenever the data changes
2. override BlockEntity#getUpdateTag and retrun a CompoundTag with the data to sync,
   override BlockEntity#handleUpdateTag to handle the data sync on client. whenever the data changes
   you need to call BlockEntity#setChanged

choose the way you prefer

I choose 2nd.
And like this?

MyBlockEntity

    private final FluidTank fluidTank = createFluidTank();
    private final LazyOptional<IFluidHandler> fluidHandler = LazyOptional.of(() -> fluidTank); 

    ...

    public void loadClient(CompoundTag tag) {
        if (tag.contains("Fluid")) {
            fluidTank.readFromNBT(tag.getCompound("Fluid"));
        }
    }

    public void saveClient(CompoundTag tag) {
        CompoundTag fluid = new CompoundTag();
        fluidTank.writeToNBT(fluid);
        tag.put("Fluid", fluid);
    }

    @NotNull
    @Override
    public CompoundTag getUpdateTag() {
        CompoundTag tag = super.getUpdateTag();
        saveClient(tag);
        return tag;
    }

    @Override
    public void handleUpdateTag(CompoundTag tag) {
        if (tag != null) {
            loadClient(tag);
        }
    }

    ...

    private FluidTank createFluidTank() {
        return new FluidTank(FLUID_CAPACITY, (fluid -> fluid.getFluid().is(FluidTags.LAVA))) {
            @Override
            protected void onContentsChanged() {
                setChanged();
            }
        };
    }

    @Override
    public <T> LazyOptional<T> getCapability(@NotNull Capability<T> cap, @Nullable Direction side) {
        if (cap == CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY) {
            return fluidHandler.cast();
        } else {
            return super.getCapability(cap, side);
        }
    }

And MyContainerMenu

    public FluidStack getFluid() {
        return blockEntity.getCapability(CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY).map(f -> f.getFluidInTank(0).copy()).orElse(null);
    }

And In Screen:

	FluidStack fluid = menu.getFluid()

The values are out of sync.

Edited February 24, 2022 by reasure
The values ​​are out of sync.

[reasure]

In the mcjty tutorial I saw, inventory was synchronized using slots and energy using data slots. But what about fluid?

[reasure]

Ok, Thank you.

[reasure]

2 hours ago, diesieben07 said:

You probably need a custom packet if you want to synchronize it in the Menu.

Sorry to keep asking basic questions.

More specifically, after creating a packet from the server to the client, should I send this packet in sendAllDataToRemoted() of the Menu class?

Edited February 25, 2022 by reasure

[Luis_ST]

send the data whenever the data changed

[reasure]

Synchronization from server to client was successful.
However, when I reconnected to the world, it was out of sync. (It says the fluid is empty.)
What's wrong?

(If the fluid changes again, it will resynchronize.)

In MyBlockEntity.class

    @Override
    public void setChanged() {
        super.setChanged();
        onFluidChanged();
    }

    private void onFluidChanged() {
        if (level != null) {
            PacketHandler.INSTANCE.send(PacketDistributor.TRACKING_CHUNK.with(() -> level.getChunkAt(worldPosition)),
                    new FluidUpdatePacket(worldPosition, fluidTank.getFluid()));
        }
    }

@Override
    public void load(CompoundTag tag) {
        ...
        if (tag.contains("Fluid")) {
            fluidTank.readFromNBT(tag.getCompound("Fluid"));
        }
        super.load(tag);
        onFluidChanged();
    }

Edited February 26, 2022 by reasure

[reasure]

It seems to have been solved by rewriting the code from scratch. thank you!
Is it correct to do this?
If this method is correct, I will post the code for other people to refer to as well.
(For other parts, refer to mcjty's block entity and container tutorial.)
there's a bug again. Real-time update doesn't work.
Should the block entity also send packets?

(Container Class)

public class LavaGeneratorMenu extends AbstractContainerMenu {
    private final BlockEntity blockEntity;
    private final ContainerLevelAccess access;
    private final IItemHandler playerInventory;
    private FluidStack fluid;
    private final Player player;

    public LavaGeneratorMenu(int windowId, Inventory playerInv, BlockPos pos) {
        super(ModMenuTypes.LAVA_GENERATOR_CONTAINER.get(), windowId);
        this.playerInventory = new InvWrapper(playerInv);
        this.access = ContainerLevelAccess.create(playerInv.player.level, pos);
        this.player = playerInv.player;
        this.fluid = FluidStack.EMPTY;
        ...
    }

    public FluidStack getFluid() {
        return blockEntity.getCapability(CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY).map(f -> f.getFluidInTank(0)).orElse(FluidStack.EMPTY);
    }

    @Override
    public boolean stillValid(@NotNull Player player) {
        return stillValid(access, player, ModBlocks.LAVA_GENERATOR.get());
    }
  
    @Override
    public void broadcastChanges() {
        super.broadcastChanges();
        if (player instanceof ServerPlayer sp) {
            FluidStack newFluid = getFluid();
            if (fluid.getAmount() != newFluid.getAmount() || !fluid.isFluidEqual(newFluid)) {
                PacketHandler.INSTANCE.send(PacketDistributor.PLAYER.with(() -> sp),
                        new FluidUpdatePacket(blockEntity.getBlockPos(), newFluid));
                this.fluid = newFluid;
            }
        }
    }

    @Override
    public void sendAllDataToRemote() {
        super.sendAllDataToRemote();
        if (player instanceof ServerPlayer sp) {
            PacketHandler.INSTANCE.send(PacketDistributor.PLAYER.with(() -> sp),
                    new FluidUpdatePacket(blockEntity.getBlockPos(), getFluid()));
        }
    }
}

(FluidUpdatePacket)

public class FluidUpdatePacket {
    public final BlockPos bePos;
    public final FluidStack fluid;

    public FluidUpdatePacket(BlockPos pos, FluidStack fluid) {
        this.bePos = pos;
        this.fluid = fluid;
    }

    public void encode(FriendlyByteBuf buffer) {
        buffer.writeBlockPos(bePos);
        buffer.writeFluidStack(fluid);
    }

    public static FluidUpdatePacket decode(FriendlyByteBuf buffer) {
        return new FluidUpdatePacket(buffer.readBlockPos(), buffer.readFluidStack());
    }

    public static void handle(FluidUpdatePacket msg, Supplier<NetworkEvent.Context> ctx) {
        AtomicBoolean success = new AtomicBoolean(false);
        ctx.get().enqueueWork(() -> {
            DistExecutor.unsafeRunWhenOn(Dist.CLIENT, () -> () -> success.set(ClientAccess.updateFluid(msg.bePos, msg.fluid)));
        });
        ctx.get().setPacketHandled(success.get());
    }
}

(ClientAccess (needed in Packet))

public class ClientAccess {
    public static boolean updateFluid(BlockPos pos, FluidStack fluid) {
        AtomicBoolean success = new AtomicBoolean(false);
        if (Minecraft.getInstance().level != null) {
            final BlockEntity blockEntity = Minecraft.getInstance().level.getBlockEntity(pos);
            if (blockEntity != null) {
                blockEntity.getCapability(CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY).ifPresent(h -> {
                    if (h instanceof FluidTank tank) {
                        tank.setFluid(fluid);
                        success.set(true);
                    }
                });
            }
        }
        return success.get();
    }
}

Edit) I removed the "if (fluid.getAmount() != newFluid.getAmount() || !fluid.isFluidEqual(newFluid)) {" which is part of the container class and synchronized it unconditionally, and it worked fine.

Edited February 27, 2022 by reasure
there's a bug again. Real-time update doesn't work.

[reasure]

In Container class, I change "this.fluid = newFluid;" -> "this.fluid = newFluid.copy();" And It works correctly.

And I wonder if I should use fluid.copy() in Packet as well.

[Luis_ST]

1 hour ago, reasure said:

Should the block entity also send packets?

if you only change the Capability while the Menu is open, then no