@Override
	public void breakBlock(World worldIn, BlockPos pos, IBlockState state) {
		TileEntity tileentity = worldIn.getTileEntity(pos);

		if (tileentity instanceof TileEntityUberTable) {
			TileEntityUberTable tileentityiubertable = (TileEntityUberTable) tileentity;

			if (!tileentityiubertable.isEmpty()) {
				ItemStack itemstack = new ItemStack(Item.getItemFromBlock(this), 1, 0);
				NBTTagCompound nbttagcompound = new NBTTagCompound();
				NBTTagCompound nbttagcompound1 = new NBTTagCompound();

				nbttagcompound.setTag("BlockEntityTag", ((TileEntityUberTable) tileentity).writeToNBT(nbttagcompound1));
				itemstack.setTagCompound(nbttagcompound);

				if (tileentityiubertable.hasCustomName()) {
					itemstack.setStackDisplayName(tileentityiubertable.getName());

					tileentityiubertable.setCustomName("Uber Table");
				}
				spawnAsEntity(worldIn, pos, itemstack);

				worldIn.updateComparatorOutputLevel(pos, state.getBlock());
			}
			super.breakBlock(worldIn, pos, state);
		}
	}

 

This is a chest, if it's empty and I break it, it drops only 1 item(the chest itself) but if I put something inside it, it drops two items, one has nbt(It's a chest with the items saved in it), the other one doesn't, it's just an empty chest

The fact that the chest being not-empty causes the undesired behavior, we can look at your code and find that you have a conditional for exactly this case:

if (!tileentityiubertable.isEmpty()) {

Therefore, this code is responsible for dropping one of the two items.

spawnAsEntity(worldIn, pos, itemstack);

Oh, look, it does.

 

However we know that this is also the version we want to drop therefore it must be something else that's causing the empty copy to drop. Hmm. Empty chest...wait, we get one of these when the chest is empty too! There must be a line that is probably responsible and outside that if-block.

Getting a TE...no

Casting a TE...no

Only one other line:

super.breakBlock(worldIn, pos, state);

This must be responsible.

 

Unfortunately as you did not include your whole class, I cannot be sure that the parent class is not just Block.

2 hours ago, Draco18s said:

The fact that the chest being not-empty causes the undesired behavior, we can look at your code and find that you have a conditional for exactly this case:

if (!tileentityiubertable.isEmpty()) {

Therefore, this code is responsible for dropping one of the two items.

spawnAsEntity(worldIn, pos, itemstack);

Oh, look, it does.

 

However we know that this is also the version we want to drop therefore it must be something else that's causing the empty copy to drop. Hmm. Empty chest...wait, we get one of these when the chest is empty too! There must be a line that is probably responsible and outside that if-block.

Getting a TE...no

Casting a TE...no

Only one other line:

super.breakBlock(worldIn, pos, state);

This must be responsible.

 

Unfortunately as you did not include your whole class, I cannot be sure that the parent class is not just Block.

public class BlockUberTable extends Block implements IHasModel, ITileEntityProvider

And I tried to do this

@Override
	public void breakBlock(World worldIn, BlockPos pos, IBlockState state) {
		TileEntity tileentity = worldIn.getTileEntity(pos);

		if (tileentity instanceof TileEntityUberTable) {
			TileEntityUberTable tileentityiubertable = (TileEntityUberTable) tileentity;

			if (!tileentityiubertable.isEmpty()) {
				ItemStack itemstack = new ItemStack(Item.getItemFromBlock(this), 1, 0);
				NBTTagCompound nbttagcompound = new NBTTagCompound();
				NBTTagCompound nbttagcompound1 = new NBTTagCompound();

				nbttagcompound.setTag("BlockEntityTag", ((TileEntityUberTable) tileentity).writeToNBT(nbttagcompound1));
				itemstack.setTagCompound(nbttagcompound);

				if (tileentityiubertable.hasCustomName()) {
					itemstack.setStackDisplayName(tileentityiubertable.getName());

					tileentityiubertable.setCustomName("Uber Table");
				}
				spawnAsEntity(worldIn, pos, itemstack);

				worldIn.updateComparatorOutputLevel(pos, state.getBlock());
			} else {
				super.breakBlock(worldIn, pos, state);	
			}
		}
	}

It still doesn't work, I still get 2 items

1 hour ago, diesieben07 said:

• Do not use ITileEntityProvider. Override hasTileEntity and createTileEntity.
• Do not use breakBlock for block drops, use getDrops. You will need additional checks, to preserve the TileEntity, see the forge patches to BlockFlowerPot.

https://github.com/Harystolho/UberMiner/blob/1.12/src/main/java/harystolho/uberminer/objects/blocks/BlockUberTable.java

Take a look at my class

Override hasTileEntity and createTileEntity. - OK

Do not use breakBlock for block drops, use getDrops. - OK

see the forge patches to BlockFlowerPot. - Didn't find

3 minutes ago, Harystolho said:

see the forge patches to BlockFlowerPot. - Didn't find

BlockFlowerPot line 433.

It says:

/*============================FORGE START=====================================*/

And then some functions.