I want to change some of the functionality of existing minecraft machines (piston, dropper, furnace, etc).  It seems forge is not designed to replace vanilla blocks (tough I'm told it can be done with reflection). Is there a way to add to what these do with forge event hooks?  Could I make something happen when a piston extends, or a dropper drops,or a furnace finishes smelting something?

For furnace there is PlayerEvent.ItemSmeltedEvent.  If you're interested in crafting table there is PlayerEvent.ItemCraftedEvent.  And there is a PotionBrewedEvent.

 

But for others I don't think there is.  One thing you can do is replace the vanilla ones with your own that extend the original but fire a custom event (or maybe just execute some code) when you want.

 

 

 

okay, thanks.  Just wanted to make sure before I made a mistake.