[1.10/1.9.4] Block requires a block above it to exist

[Bloopers]

I'd like to make it so that the block I have created will only work if there is a block above it(it's meant to hang from the ceiling)

 

I've looked into classes like carpet and plants since the only work if a block is UNDER them but I can't figure out how to make it so that it will be destroyed/can't be placed unless there is a block above.

 

This is the class I have right now:

 

package bloopers.climbing.blocks;

import net.minecraft.block.Block;
import net.minecraft.block.material.MapColor;
import net.minecraft.block.material.Material;
import net.minecraft.block.state.IBlockState;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.math.AxisAlignedBB;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.IBlockAccess;

public class BlockRope extends Block {

    public static final AxisAlignedBB PILLAR_AABB = new AxisAlignedBB(0.375D, 0.0D, 0.375D, 0.625D, 1.5D, 0.625D);


public BlockRope(Material blockMaterialIn, MapColor blockMapColorIn) {
	super(Material.CLOTH, blockMapColorIn.BROWN);
}

    public AxisAlignedBB getBoundingBox(IBlockState state, IBlockAccess source, BlockPos pos)
    {
	return PILLAR_AABB;

    }

    /**
     * Used to determine ambient occlusion and culling when rebuilding chunks for render
     */
    public boolean isOpaqueCube(IBlockState state)
    {
        return false;
    }

    public boolean isFullCube(IBlockState state)
    {
        return false;
    }

    @Override
    public boolean isLadder(IBlockState state, IBlockAccess world, BlockPos pos, EntityLivingBase entity) { return true; }

    

}

[Leviathan143]

Override Block#canPlaceBlockAt() to return false if there is no block above.

[Bloopers]

Override Block#canPlaceBlockAt() to return false if there is no block above.

I can't figure out what to put in this method, could I get a bit more detail?

[Bloopers]

You check if there is a block above and only the return true...

How can I check? (i'm a big noob when it comes to blocks, i normally make items lol)

[Bloopers]

How does that have anything to do with it?!

You get the BlockPos above another one using the

up

method. Then you use

World#getBlockState

to get the block at a position.

(probably looking super stupid)

I still don't really understand..

What is the up method, and how am I supposed to use it?

[Draco18s]

Do you understand Java?  At all?

 

The block is passed a World object and a BlockPos object.  Use them.