[SOLVED] [1.12] About inventory item consumption, should I use Capabilities?

[blfngl]

Hi there, I'm using a non-container gui to handle some inventory manipulation. A button can be clicked and items from a player's inventory should be consumed:

 

Spoiler

	@Override
	protected void actionPerformed(GuiButton button) throws IOException
	{
		if (button.equals(buttonCraft))
		{
			if (player.inventory.hasItemStack(new ItemStack(Items.APPLE)))
			{
				int index = player.inventory.findSlotMatchingUnusedItem(new ItemStack(Items.APPLE));
				player.inventory.decrStackSize(index, 1);
				player.inventory.markDirty();
			}
		}
	}

 

 

The change is marked in the inventory until I exit and then reenter the world. Am I supposed to be using Capabilities to handle this? Thanks!

Edited March 8, 2019 by blfngl
Marked as solved

[blfngl]

Thank you, I'll look into it.

[blfngl]

2 hours ago, diesieben07 said:

Capabilities have nothing to do with this. The client cannot directly make changes like this. You have to send a packet to the server and inform them that the button has been clicked. Then confirm that the action may actually performed (e.g. make sure the player is not spamming the packet) and then perform the necessary manipulations.

Thanks for the help. Figured it out!