There are several recipes in minecraft and modded minecraft that use a filled bucket in some recipe and return an empty bucket and some item. How are these recipes handled? The IRecipe api only has methods for getting one result. I need this information for my auto-crafter block. Currently this block destroyes the buckets as it just replaces the input items with the output of the recipe.

 

Thanks,

Buckets are returned automagically by the vanilla crafting system.  Warning: it returns one bucket.  If a recipe needs two (or more) those have to be handled with Forge Events.

 

With what you're doing, you're likely going to have to write your own crafting handler and include a second output slot for the buckets.  Do note that there are other (mod) recipes which deal with similar things, such as tools, that will also not-work with your current setup (e.g. RedPower's hand saw, IC2's hammer).

Ok, but given that I have an IRecipe, how can I actually detect that there are multiple outputs? I'm uncertain how to go about fixing this properly.

Try digging into the vanilla crafting handler.  It has a way to detect if the recipe inputs have a bucket-of-material and if so, to leave an empty bucket in the crafting grid.

Hi

 

Vanilla uses Item.hasContainerItem() and a few related methods.  If you search vanilla for that, you will find how the crafting recipes handle it as Draco said.

 

-TGG