Minecraft Datapack Template

Use this as a starting point for your own datapack for Minecraft Java Edition. The template provides starting pack structure, and scripts to package and install your datapack.

Prerequisites

You will need Nix to use this template. You can install it using the Determinate Systems Nix Installer.

Getting Started

1. Clone this repository.
2. Rename the directory src/data/your_datapack_namespace to a name of your choice.
3. Edit all of the files in src/data/minecraft/tags/function/ to change your_datapack_namespace to the exact name you picked for the directory in step 2.
4. Modify src/pack.mcmeta and change the "description" property to set the name and description for your datapack.
5. Replace src/pack.png with your own icon.

Where To Put Your Code

The template includes some example code that prevents creepers from breaking blocks when they explode. You probably want to replace the example code with your own.

There are three functions provided in the src/data/your_datapack_namespace/function/ directory. Each .mcfunction file defines a function.

• load.mcfunction runs when the datapack is installed - use this function for setup steps that need to run once, like adding scoreboards
• tick.mcfunction runs every game tick
• uninstall.mcfunction runs when the datapack is uninstalled - use this for cleanup, for example for removing the scoreboards that you added in load.mcfunction.

Note that those three functions are set up by the configuration in the JSON files in src/data/minecraft/tags/functions/. It is important that your datapack directory name matches the function namespace in those files!

You can adjust special scheduling for functions. For example if you don't want a function that runs on every tick for example you can delete src/data/minecraft/tags/functions/tick.json and delete src/data/your_datapack_namespace/functions/tick.mcfunction.

Reducing Lag

One way to reduce lag from your datapack is to remove the tick, and to instead schedule a function that runs less often - for example once every second. To do that use the schedule command in your load function:

schedule function your_datapack_namespace:do_something_every_second 1s

That schedules a function called your_datapack_namespace:do_something_every_second. You need to define that function by creating a new file called src/data/your_datapack_namespace/functions/do_something_every_second.mcfunction.

Make sure to clean up by stopping the scheduled function in your uninstall function:

schedule clear your_datapack_namespace:do_something_every_second

Building the Datapack

Either start the develop shell by running,

$ nix develop

or set up direnv

To package your datapack into a zip file run,

$ make

Installing

Either start the develop shell by running,

$ nix develop

or set up direnv

To install the datapack to your local Minecraft install run,

$ make install

This will automatically build the datapack package if there have been changes to source files since the package was last built.

The install script will search for saved Minecraft worlds on your computer, and prompt which one to install to. If you want to skip the prompt you can write the path to a Minecraft world to a file named selected_world.

Every time you install changes to the pack you need to run the command /reload in your Minecraft world, or restart the game.

Uninstalling

Either start the develop shell by running,

$ nix develop

or set up direnv

To uninstall the datapack run,

$ make uninstall