Resources, data packs and localisation

Status: Partly implemented. The mod’s assets/ and datapack/ folders mount as packs (mod/<id>), lang files translate cl_text_translatable keys, and lifecycle.resources_reloaded / lifecycle.data_reloaded fire after reloads. Reading resource or data files from code, reload listeners with their own stage, server-locale translation and sending server resource packs are Planned.

Concepts: Data-driven content.

Mod packs

Folder in the mod	Mounted as	Contains
assets/<ns>/	resource pack mod/<id> (above vanilla, below the player’s packs)	textures, models, block states, item model definitions, sounds.json and sounds, lang files, fonts, shaders, GUI sprites
datapack/<ns>/	data pack mod/<id> (above vanilla, below the world’s packs)	recipes, loot tables, tags, advancements, enchantments, damage types, …

The player’s resource packs and the world’s data packs can override mod files, exactly as with vanilla content.

Localisation

Put translations in assets/<ns>/lang/<locale>.json (en_us.json first; other locales fall back to it), in the vanilla format:

{
  "item.my_mod.ruby": "Ruby",
  "block.my_mod.ruby_block": "Block of Ruby",
  "my_mod.welcome": "Welcome, %s!",
  "key.my_mod.zoom": "Zoom",
  "config.my_mod.gift.rubies": "Rubies on join"
}

Key	Used for
item.<ns>.<path>, block.<ns>.<path>	Item and block names
key.<ns>.<path>	Keybind names in Controls
config.<mod id>.<path>	Labels on the Config page
anything else	cl_text_translatable(CL_STR("my_mod.welcome")) with cl_text_add_arg (Lua cl.text.translatable("my_mod.welcome", player.name))

Translatable text is translated on the client, in the player’s language, so the server sends one message to everyone.

Reload events

Event	When
lifecycle.resources_reloaded	After a resource reload on the client (F3+T, the pack screen)
lifecycle.data_reloaded	After /reload on the server

Planned

Reading raw resource files (client) and data files (server) from code, reload listeners that prepare data in the background, translating a key on the server for one player’s locale, and sending a server resource pack to players.