How to read data from custom datapack?

[Creamsicle]

Currently, I'm trying to figure out how to read in data from a custom datapack.  The intention is to have the Item have a reference to this pack (IE "modname:material/materialname") as an NBT tag, and i would overwrite some use functions based off of that.  How should I go about reading in the data from the datapack?

[diesieben07]

You need to implement PreparableReloadListener. Usually you should subclass SimplePreparableReloadListener which provides a framework for splitting your I/O and main thread work. You can also use SimpleJsonResourceReloadListener, which will support a directory structure of JSON files similar to the vanilla tags or recipes.

Then use AddReloadListenerEvent to register your reload listener.