[1.10] Adding custom drops to a vanilla block (mob spawner)

[Aarilight]

The only way I've seen to be able to change the drops of a block is to override Block.getDrops() in a Block subclass. Is there a way that I can modify the drops of a vanilla block without creating a subclass for it, and replacing instances of it in the world with my new one?

Edited February 15, 2017 by Aarilight
(updated title for future searchers)

[larsgerrits]

Subscribe to the HarvestDropsEvent, which will give you access to drops and the harvester. More info on events here.

[Aarilight]

@SubscribeEvent
public static void onSpawnerHarvest(BlockEvent.HarvestDropsEvent event) {
	if (event.getState().getBlock() == Blocks.MOB_SPAWNER) {
		
	}
}

How do I edit the drops from here? the event doesn't seem to have any useful methods to replace them. Do I have to prevent the normal event and drop the items myself?

Edited February 15, 2017 by Aarilight
update code language

[larsgerrits]

The HarvestDropsEvent contains a List<ItemStack> called drops. You can modify this List<ItemStack> however you want.

[Aarilight]

Oh, I was being dumb. I saw .getDrops() and was thinking I'd need .setDrops(). It's the same object, so editing it does the same thing. #genius

 

 

Edited February 15, 2017 by Aarilight

[Aarilight]

In case anyone is ever trying to change the drops of a mob spawner based on the type it is, in the future, and found this old post, and got sad, there is a way!

 

You must subscribe to both BreakEvent and HarvestDropsEvent. In BreakEvent, when it's a Blocks.MOB_SPAWNER, set a static field to the TileEntityMobSpawner.

In the HarvestDropsEvent, when the same condition is met, use the TileEntityMobSpawner you saved.