Runtime Registry Extender

An absurdly twisted library mod to add entries at runtime to the just as absurdly twisted Minecraft registries.

Please note that "runtime" here is limited to a few phases of the game loop to avoid random breakage.

Additionally, this only allows adding new entries to the aforementioned registries but not modifying their frozen base, also as a matter of stability.

The core point of these limitations is to allow servers/worlds to provide extra values for the players' games to take into account, without having to restart the game or launch a whole other configuration every time.

Right now, only registry entries are affected. Any related asset (models, textures, translations, etc.) will still have to be either present locally or provided by some other mean (e.g. server resource pack, locally present assets)

To avoid imposing on mod authors having to meddle with the pointlessly intricate registries structure, this mod provides a few entrypoints allowing mod authors to set everything up quite easily:

• runtime_registry_extender:extension_setup: must be of type ExtendableRegistryInitializer
  • Is executed before registries’ initialisation! Mind your static values!
  • Allows providing registry keys for which to make registries extendable.
    • Other registries will not be made extendable! Make sure to provide it for all of your needs.
    • Allows providing invalid block states adapters, allowing to replace any unknown block state with another one.
      • These are only executed for block states. Work will be put towards supporting other data types.
      • This only affects the block state, block entity data is not (yet?) adaptable via such means.
      • Adapters only receive raw data in a NBT format, as read from the region files, and return theoretically valid NBT data.
  • runtime_registry_extender:values_loader: must be of type RegistryExtensionLoader
    • Allows registering the extension values. Any value provided for a registry that wasn't made extendable will cause issues. It is split between builtin registries' extension values registration and reloadable registries' extension values registration to ensure that values aren't registered too early nor too late, while still providing access to the appropriate data source. (i.e. to allow registering entries based on data-driven capabilities)
    • Is executed at the beginning of data reloading, before other giving way to other reloading, to ensure providing extension entries to the following phases. (e.g. making sure that extension entries can be reached upon loading tags)
    • Allows providing invalid elements adapters, allowing to replace any unknown element with another one.
      • Other data types will be supported in the future.
      • Adapters only receive raw data in a NBT format, as read from the region files, and return theoretically valid NBT data.
      • You can only register one adapter per element type (block state, item stack...) per element namespace and per adapter name. Trying to register a duplicate will be ignored.
      • So far adapters support the following: block states, fluid states, item stacks, mob effects and block entity types.
    • The entrypoint is always provided with a helper for registering various more tricky element types that either might require some post-registration processing or hare not standardly registered. For instance, the block and fluid registration helper methods will automatically handle registering appropriate block states and fluid states.

Platform

This mod is made for the Fabric modloader, and will only ever support Fabric.

I have little to no doubt that this mod will break on forge-based loaders. And attempting to load it with Sinytra likely will not work either.

This mod reimplements registries in ways that are incompatible with the forge-based toolchain, and I am neither willing to put in the work to make an equivalent for NeoForge, nor endorsing people porting this mod for it. In case you may wonder, the licence does prevent distribution of unauthorised ports and forks, and I preventively inform you of a strict refusal of any port to the aforementioned toolchain, or its predecessor.