[1.8] [SOLVED] Item added to inventory disappearing on world load

[AstroEngiSci]

I'm building a mod that, among other things, contains teleporters. The location of target teleporters is stored in punch cards. On right-click on a teleporter with a blank punch card, the blank card is replaced with a written card. Then, the location of the target teleporter is written to the written card's NBT.

 

All of that works just fine. The problem comes when reloading the world; for whatever reason, written punch cards don't persist in inventories through a world reload. I suspect the problem lies in my implementation of NBT. I don't totally understand NBT; it makes a convenient scapegoat.

 

The code that replaces punch cards:

 

	public boolean onBlockActivated(World worldIn, BlockPos pos, IBlockState state, EntityPlayer playerIn, EnumFacing side, float hitX, float hitY, float hitZ) {
	//Get the tile entity of this teleporter
	TeleporterTileEntity t = (TeleporterTileEntity) worldIn.getTileEntity(pos);
	//Check if they're holding a blank punch card
	ItemStack item = playerIn.getCurrentEquippedItem();
	if(item != null && item.getItem() == EnderScience.blankPunch) {
		//Replace with written card
		ItemStack card = new ItemStack(EnderScience.writtenPunch, 1);
		int slot = playerIn.inventory.currentItem;
		playerIn.replaceItemInInventory(slot, card);
		//Store this teleporter's coordinates in the new punch card
		NBTTagCompound tag = new NBTTagCompound();
		tag.setString("teleporter", pos.getX() + " " + pos.getY() + " " + pos.getZ());
		card.setTagCompound(tag);
		if(playerIn.getCurrentEquippedItem().getTagCompound() == null)
			System.out.println("[Ender Science]: Failed to write card's NBT.");
		System.out.println("[Ender Science]: Teleporter coordinates: " + tag.getString("teleporter"));
		return true;
	}
	else if (item != null && item.getItem() == EnderScience.writtenPunch){
		//TODO: Fix teleport call
		t.teleport(playerIn, worldIn, item.getTagCompound().getString("teleporter"));
		return true;
	}
	return true;
}

 

And the base class for the written punch card:

 

public class WrittenPunchCard extends Item {
public WrittenPunchCard()
{
	setMaxStackSize(1);
	setUnlocalizedName("writtenpunch");
	setCreativeTab(EnderScience.tab);
}

@Override
public void addInformation(ItemStack stack, EntityPlayer playerIn, List tooltip, boolean advanced) 
{
	tooltip.add("Coordinates: " + stack.getTagCompound().getString("teleporter"));
}
}

 

The problem persists when I comment out the code that writes the teleporter coordinates to the punch card.

[Ernio]

public boolean onBlockActivated(World worldIn, BlockPos pos, IBlockState state, EntityPlayer playerIn, EnumFacing side, float hitX, float hitY, float hitZ)
{
	if (!worldIn.isRemote) // run on server
	{
		TeleporterTileEntity t = (TeleporterTileEntity) worldIn.getTileEntity(pos);
		if (t != null)
		{
			ItemStack stack = playerIn.getCurrentEquippedItem();
			if (stack != null && stack.getItem() == EnderScience.card) // you don't need separate items, but if you do... well, you can replace ItemStack like you did before, just do it on server.
			{
				NBTTagCompound nbt = stack.getTagCompound();
				if (nbt == null)
				{
					nbt = new NBTTagCompound();
					stack.setTagCompound(nbt);
				}

				if (!nbt.getBoolean("punch")) // has NBT, but not punched, so punch
				{
					nbt.setBoolean("punched", true);
					nbt.setInteger("x", pos.getX());
					nbt.setInteger("y", pos.getY());
					nbt.setInteger("z", pos.getZ());
					System.out.println("[Ender Science]: Teleporter coordinates: " + pos.getX() + " / " + pos.getY() + " / " + pos.getZ());
				}
				else // punched, teleport
				{
					t.teleport(playerIn, worldIn, nbt.getInteger("x"), nbt.getInteger("y"), nbt.getInteger("z")); // change it to 3-arg coords.
				}
			}
		}
	}
	return true;
}

 

Ahh... this can be done nicer....

[coolAlias]

Ahh... this can be done nicer....

Lol, yeah, I'd probably try to reduce the indentation a few levels, for one

public boolean onBlockActivated(World world, BlockPos pos, IBlockState state, EntityPlayer player, EnumFacing side, float hitX, float hitY, float hitZ)
{
TileEntity te = world.getTileEntity(pos);
ItemStack stack = player.getHeldItem();
if (!worldIn.isRemote && te instanceof TeleporterTileEntity && stack != null && stack.getItem() == EnderScience.card)
{
	// now we're cookin' with a whole lot less mess 
	// do all your other stuff here
}
}

 

But that's not really related to your problem... your problem sounds to me like you are managing the inventory from a client-side GUI and expecting it to persist, but the client is like a dream or a ghost - it is completely ephemeral.

 

You need to make sure that any setting you do, be it adding items to inventories or changing NBT data, is done on the server.

[Ernio]

Ahh... this can be done nicer....

Lol, yeah, I'd probably try to reduce the indentation a few levels, for one

 

This is what happens when you get back to "micro-optimization-is-bullshit-java" after finishing algorithmics project in savage C (notice how hard I tried to declare fields in smallest scopes and other mad shit and I didn't even do that well thing well - #sleepy)...

Worthless code. And yeah - main point was to use world.isRemote (which he OP didn't in main post).

[AstroEngiSci]

Thank you both! I modified the system so that written punch cards have different metadata than unwritten (I want them to have different names and have distinct icons). The call for server-only fixed the persistence issue; however, I have to call my teleport code client-side for it to work.

 

The teleport code just calls player.setPosition(). Is there some other way I should be doing this so that it works from server-side?

[Ernio]

There should be similar method "setPositionAndUpdate" . Look into vanilla, you should find it.

[AstroEngiSci]

Thank you both.