[1.16.4] Write custom object to World NBT

[TheOrangeInd]

I have fluid pipes in my mod and I use a custom Grid object to distribute fluid in this pipes. This Grid object does not inherit either Tilentity or Entity, but I need to write data from it to the world NBT. The only solution that I have found is to create my own class that inherits WorldSavedData. The problem is that I don't quite understand how to use it correctly in newer versions of the game and I'm not sure if this is the best way. I would be very grateful for any advice.

Custom WorldSavedData implementation: 

public class NBTHandler extends WorldSavedData
{
    private static final String DATA_IDENTIFIER = MainClass.MODID + "_nbt";

    public final Set<ISaveable> subscribers = new HashSet();

    public NBTHandler() { this(DATA_IDENTIFIER); }
    public NBTHandler(String name) { super(name); }

    public static NBTHandler get(World world)
    {
        if(!(world instanceof ServerWorld)) throw new RuntimeException("Attempted to get data from client.");
        ServerWorld w = (ServerWorld)world;
        DimensionSavedDataManager storage = w.getSavedData();
        return storage.getOrCreate(NBTHandler::new, DATA_IDENTIFIER);
    }

    public void addSubscriber(ISaveable s) { subscribers.add(s); }

    @Override
    public boolean isDirty()
    {
        boolean flag = false;
        for (ISaveable item : subscribers) flag &= item.isDirty();
        return super.isDirty() || flag;
    }

    @Override
    public void read(CompoundNBT nbt)
    {
        subscribers.forEach(item -> item.readFromNBT(nbt));
    }

    @Override
    public CompoundNBT write(CompoundNBT nbt)
    {
        subscribers.forEach(item -> item.writeToNBT(nbt));
        return nbt;
    }
}

 

[TheOrangeInd]

The point is that my Grid is not tied to any position in the world. It acts as a data store for connected pipes, from which these pipes can extract information about the contained fluid when interacting with the world. So, is there a way to avoid binding the Grid to specific chunks?

[TheOrangeInd]

Is there any recent documentation for WorldSaveData? I have a rather poor understanding of how it should be attached to the world.

[TheOrangeInd]

Should I call the read and write methods of my NBTHandler in any event?

[TheOrangeInd]

For some reason, the read(), wright() and isDirty() methods are not called. I cannot figure out what I am missing.

[TheOrangeInd]

After fixing some mistakes, I managed to write my Grid to the world NBT. But the reading is still not happening. Under what conditions is the read() method called?

NBTHandler class:

public class NBTHandler extends WorldSavedData
{
    private static final String DATA_IDENTIFIER = MainClass.MODID + "_nbt";

    public final Set<ISaveable> subscribers = new HashSet();

    public NBTHandler() { this(DATA_IDENTIFIER); }
    public NBTHandler(String name) { super(name); }

    public static NBTHandler get(World world)
    {
        if(!(world instanceof ServerWorld)) throw new RuntimeException("Attempted to get data from client.");
        DimensionSavedDataManager storage = ServerLifecycleHooks.getCurrentServer().func_241755_D_().getWorld().getSavedData();
        //DimensionSavedDataManager storage = ((ServerWorld)world).getSavedData();
        return storage.getOrCreate(NBTHandler::new, DATA_IDENTIFIER);
    }

    public void addSubscriber(ISaveable s) { subscribers.add(s); }

    @Override
    public boolean isDirty()
    {
        boolean flag = false;
        for (ISaveable item : subscribers) flag |= item.isDirty();
        return super.isDirty() || flag;
    }

    @Override
    public void read(CompoundNBT nbt)
    {
        subscribers.forEach(item -> item.readFromNBT(nbt));
    }

    @Override
    public CompoundNBT write(CompoundNBT nbt)
    {
        subscribers.forEach(item -> item.writeToNBT(nbt));
        return nbt;
    }
}

And get() method call in my Grid class:

@Override
public boolean addPipe(IPipe pipe)
{
    if(this.world == null)
    {
        world = ((TileEntity)pipe).getWorld();
        if(world != null) NBTHandler.get(world).addSubscriber(this);
    }
  
        /*some code*/
    return false;
}

 

 

Edited April 20, 2021 by TheOrangeInd