[1.15.2] How do I create a crafting recipe which damages an item?

[superminerJG]

I have three items involved: a sledgehammer, copper ore and copper dust.

When you craft the sledgehammer and the copper ore together (shapeless), it should give you copper dust.

However, the sledgehammer stays on the crafting grid and loses 1 durability.

 

Can this be done through JSON, or do I have to code it in to get it to work? If I do have to code it in, how?

Edited April 28, 2020 by superminerJG

[Draco18s]

Your hammer needs to overrhide hasContainerItem and getContainerItem. In the second take in the passed stack, tryDamage it, and return it.

[superminerJG]

I see how this is. However, do you have an example (maybe from an existing mod) that I can look at?

[Draco18s]

Look at the bucket. Yes it doesn't damage the item, but t does override the relevant method.

Edited April 28, 2020 by Draco18s

[superminerJG]

https://gist.github.com/JGgithub2018/3da9f4640bfb29d853325105f908fd28

 

This is the bucket class, and it appears to not have the mentioned methods. oof.

[Draco18s]

That might be the Forge bucket. Look for the MilkBucket.

[Boy132]

7 hours ago, superminerJG said:

However, do you have an example (maybe from an existing mod) that I can look at?

This should work:

@Override
public boolean hasContainerItem()
{
  return true;
}

@Override
public ItemStack getContainerItem(ItemStack itemStack)
{
  ItemStack stack = itemStack.copy();
  if(stack.attemptDamageItem(1, random, null))
  {
    stack.shrink(1);
    stack.setDamage(0);
  }
  return stack;
}

 

 

EDIT: And of course set the max damage in your item's properties. (maxDamage)

Edited April 29, 2020 by Boy132

[DavidM]

46 minutes ago, Boy132 said:

This should work:

@Override
public boolean hasContainerItem()
{
  return true;
}

@Override
public ItemStack getContainerItem(ItemStack itemStack)
{
  ItemStack stack = itemStack.copy();
  if(stack.attemptDamageItem(1, random, null))
  {
    stack.shrink(1);
    stack.setDamage(0);
  }
  return stack;
}

 

 

EDIT: And of course set the max damage in your item's properties. (maxDamage)

Please don’t post copy-pasta code like this in the future. Others will just copy it without learning anything.

[Boy132]

12 minutes ago, DavidM said:

Please don’t post copy-pasta code like this in the future. Others will just copy it without learning anything.

I totally agree with you. I thought in this case it's fine because the code isn't complex at all and there is no real vanilla reference to look at. ^^

[superminerJG]

So, what is the purpose of getContainerItem here?

 

(i.e. when is it called, and what should it do)

Edited April 29, 2020 by superminerJG

[superminerJG]

On 4/29/2020 at 2:57 AM, Boy132 said:

This should work:

@Override
public boolean hasContainerItem()
{
  return true;
}

@Override
public ItemStack getContainerItem(ItemStack itemStack)
{
  ItemStack stack = itemStack.copy();
  if(stack.attemptDamageItem(1, random, null))
  {
    stack.shrink(1);
    stack.setDamage(0);
  }
  return stack;
}

 

 

EDIT: And of course set the max damage in your item's properties. (maxDamage)

Why not just return a copy of ItemStack.EMPTY instead of setting count to zero and resetting damage?

[Draco18s]

3 hours ago, superminerJG said:

Why not just return a copy of ItemStack.EMPTY instead of setting count to zero and resetting damage?

Functionally an itemstack with a size of zero is the same as an empty stack. So do what you like.