Hi yall, I need help for this is my first time to attempt DataFixing my mod rely heavily on metadata, one example is my dragon egg block that is split into custom breeds by metadata, so I want to make it it's own block but the world saves might remember it's old name, all egg breeds are registered as dragonEgg but I have to make each block and fix it.

 

BlockDragonBreedEgg.class:https://github.com/TheRPGAdventurer/dragonmounts2-1.12.2/blob/master/src/main/java/com/TheRPGAdventurer/ROTD/client/blocks/BlockDragonBreedEgg.java

Wait untill 1.13 is even available for modding, then ask the question. There will likely be a way to hook into the conversion methods to map metadata to corresponding blockstates. Vanilla has this option, why wouldn't mods have it too?

However as of right now it is too early to worry about this. Wait untill an mdk for 1.13 is released.

I am trying to fix another bug on my mod by removing it's metadata, it's particle effects is like always the original block, eg. the block is green particle when falled upon by mobs or broken is black because the default ender dragon egg is black.

If you're already working on it, or if you're making new stuff, the best way to "future proof" for 1.13 is to perform the flattening yourself. Basically make all variants of your blocks a separate block. This should generally be compatible and you can move to such a scheme now in 1.12.2.

 

However, I agree with VoidWalker that otherwise I wouldn't worry about it until we see how 1.13 works and what provisions it already has for data fixing.

ok 1.13 i here rewrote my blocks invidually now how do i datafix? I saw choonsters code but i find it too complicated how does it work to it core?

dont bother w/ it modded world are going to break

so all our dragon eggs would jut disappear?

1 hour ago, TheRPGAdventurer said:

so all our dragon eggs would jut disappear?

I think he is implying that many mods won't do any data-fixing and so heavily modded games are going to end up having to start brand new worlds. If your server only runs your own mod, then sure, go ahead and look into data-fixing.

Data fixers are a massive mess. Good luck getting them to work, @itsmeow can probably share some knowledge 

Mojang designed the datafixer system with only vanilla in mind. There is no system implemented for modders 1.13.