fabric-datagen

A hacky extension to Fabric Loom that adds support for generating data at build time.
Example mod at goodasintended/fabric-datagen-example-mod

Setup

1. Add badasintended maven repository to settings.gradle

   pluginManagement {
       repositories {
           maven {
               name = 'Fabric'
               url = 'https://maven.fabricmc.net/'
           }
   ++      maven {
   ++          name = 'badasintended'
   ++          url = 'https://maven.bai.lol/'
   ++      }
           gradlePluginPortal()
       }
   }

2. Add fabric-datagen into the plugins block on your build.gradle

   plugins {
       id 'fabric-loom' version '0.9-SNAPSHOT'
   ++  id 'lol.bai.fabric-datagen' version '0.3.+'
       id 'maven-publish'
   }

3. On datagen source set, create a class that implements DataInitializer, install your providers there

   public class ExampleData implements DataInitializer {
       @Override
       public void onInitializeData(DataGenerator generator, GeneratorOptions options) {
           generator.install(new BlockTagsProvider(generator));
       }
   }

4. Create a fabric.mod.json in the datagen source set, add your class to bai:datagen entrypoint

   {
     "schemaVersion": 1,
     "id"           : "example-data",
     "version"      : "1",
     "entrypoints"  : {
       "bai:datagen": ["com.example.data.ExampleData"]
     }
   }

5. Add your data mod id to the datagen block on your build.gradle

   datagen {
       mods("example-data")
   }

6. Run runData gradle task
7. Build your mod jar

.gitignore

Most of the time you don't really need to include the generated files to the git history, so you can add it to the .gitignore file.

src/generated/

But, if you want to include those files, I recommend only ignoring the cache folder instead.

src/generated/resources/.cache/

Configurations

You can specify the source set used and the output directory to your liking. To do that, add a datagen block to your build.gradle.

datagen {
    sourceSet = sourceSets.main
    output = file('src/main/resources')
}

Though keep in mind that you need to add the main classpath if you use custom source set, also the output won't be automatically included in the jar.