What is the point of DeferredRegister?

[Vakror]

I've been modding forge and fabric for a while now. Why does forge use its DeferredRegister instead of vanilla registries?

[warjort]

https://forge.gemwire.uk/wiki/Registration

You don't have to use DeferredRegister. You can use RegisterEvent instead. But DeferredRegister is recommended as less error prone.

 

As to the difference.

Fabric unfreezes the registries throughout the mod loading process.

That makes it simpler and gives you more flexibility, but it is inherently unsafe and can lead to bugs if you don't know what you are doing.

 

Forge only lets you register things when it is safe to do so. Forge has a state model that defines when things should be done, see its ModLoadingStages.

e.g. with forge it is guaranteed that all custom registries including those created by other mods exist before any mods start registering objects.

 

The use of the well defined state model, allows forge to run certain parts of the mod loading in parallel (in principle speeding it up).