Resolve #470 (#471)

Co-authored-by: Max <maxh2709@gmail.com>

common/src/main/java/dev/architectury/registry/registries/RegistrarManager.java

@@ -78,6 +78,12 @@ public final class RegistrarManager {
         return this.provider.builder((Class<T>) typeGetter.getClass().getComponentType(), registryId);
     }
     
+    @SafeVarargs
+    public final <T> RegistrarBuilder<T> builderDefaulted(ResourceLocation registryId, ResourceLocation defaultId, T... typeGetter) {
+        if (typeGetter.length != 0) throw new IllegalStateException("array must be empty!");
+        return this.provider.builderDefaulted((Class<T>) typeGetter.getClass().getComponentType(), registryId, defaultId);
+    }
+    
     /**
      * Registers a non-synced dynamic registry.
      *
@@ -174,6 +180,8 @@ public final class RegistrarManager {
         
         <T> RegistrarBuilder<T> builder(Class<T> type, ResourceLocation registryId);
         
+        <T> RegistrarBuilder<T> builderDefaulted(Class<T> type, ResourceLocation registryId, ResourceLocation defaultId);
+        
         <T> void registerDynamicRegistry(ResourceKey<Registry<T>> key, Codec<T> dataCodec);
         
         <T> void registerDynamicRegistrySynced(ResourceKey<Registry<T>> key, Codec<T> dataCodec, Codec<T> networkCodec);

fabric/src/main/java/dev/architectury/registry/registries/fabric/RegistrarManagerImpl.java

@@ -97,6 +97,11 @@ public class RegistrarManagerImpl {
             return new RegistrarBuilderWrapper<>(modId, FabricRegistryBuilder.createSimple(type, registryId));
         }
         
+        @Override
+        public <T> RegistrarBuilder<T> builderDefaulted(Class<T> type, ResourceLocation registryId, ResourceLocation defaultId) {
+            return new RegistrarBuilderWrapper<>(modId, FabricRegistryBuilder.createDefaulted(type, registryId, defaultId));
+        }
+        
         @Override
         public <T> void registerDynamicRegistry(ResourceKey<Registry<T>> key, Codec<T> dataCodec) {
             DynamicRegistries.register(key, dataCodec);
@@ -133,9 +138,9 @@ public class RegistrarManagerImpl {
     
     public static class RegistrarBuilderWrapper<T> implements RegistrarBuilder<T> {
         private final String modId;
-        private FabricRegistryBuilder<T, MappedRegistry<T>> builder;
+        private FabricRegistryBuilder<T, ? extends MappedRegistry<T>> builder;
         
-        public RegistrarBuilderWrapper(String modId, FabricRegistryBuilder<T, MappedRegistry<T>> builder) {
+        public RegistrarBuilderWrapper(String modId, FabricRegistryBuilder<T, ? extends MappedRegistry<T>> builder) {
             this.modId = modId;
             this.builder = builder;
         }

minecraftforge/src/main/java/dev/architectury/registry/registries/forge/RegistrarManagerImpl.java

@@ -181,6 +181,12 @@ public class RegistrarManagerImpl {
                     .setName(registryId), registryId);
         }
         
+        @Override
+        public <T> RegistrarBuilder<T> builderDefaulted(Class<T> type, ResourceLocation registryId, ResourceLocation defaultId) {
+            return new RegistryBuilderWrapper<>(this, new net.minecraftforge.registries.RegistryBuilder<>()
+                    .setName(registryId).setDefaultKey(defaultId), registryId);
+        }
+        
         @Override
         public <T> void registerDynamicRegistry(ResourceKey<Registry<T>> key, Codec<T> dataCodec) {
             if (newDynamicRegistries == null) {

neoforge/src/main/java/dev/architectury/registry/registries/forge/RegistrarManagerImpl.java

@@ -143,6 +143,11 @@ public class RegistrarManagerImpl {
             return new RegistryBuilderWrapper<>(this, new RegistryBuilder<>(ResourceKey.createRegistryKey(registryId)));
         }
         
+        @Override
+        public <T> RegistrarBuilder<T> builderDefaulted(Class<T> type, ResourceLocation registryId, ResourceLocation defaultId) {
+            return new RegistryBuilderWrapper<>(this, new RegistryBuilder<T>(ResourceKey.createRegistryKey(registryId)).defaultKey(defaultId));
+        }
+        
         @Override
         public <T> void registerDynamicRegistry(ResourceKey<Registry<T>> key, Codec<T> dataCodec) {
             if (newDynamicRegistries == null) {

testmod-common/src/main/java/dev/architectury/test/registry/TestRegistries.java

@@ -75,9 +75,18 @@ public class TestRegistries {
         public TestInt(int value) {
             this.value = value;
         }
+        
+        @Override
+        public String toString() {
+            return Integer.toString(value);
+        }
     }
     
-    public static final Registrar<TestInt> INTS = RegistrarManager.get(TestMod.MOD_ID).<TestInt>builder(new ResourceLocation(TestMod.MOD_ID, "ints"))
+    public static final Registrar<TestInt> INTS = RegistrarManager.get(TestMod.MOD_ID)
+            .<TestInt>builderDefaulted(
+                    new ResourceLocation(TestMod.MOD_ID, "ints"),
+                    new ResourceLocation(TestMod.MOD_ID, "test_no_int")
+            )
             .syncToClients()
             .build();
     public static final DeferredRegister<CreativeModeTab> TABS = DeferredRegister.create(TestMod.MOD_ID, Registries.CREATIVE_MODE_TAB);
@@ -101,6 +110,7 @@ public class TestRegistries {
             .bucketItemSupplier(() -> TestRegistries.TEST_FLUID_BUCKET)
             .color(0xFF0000);
     
+    public static final RegistrySupplier<TestInt> TEST_NO_INT = INTS.register(new ResourceLocation(TestMod.MOD_ID, "test_no_int"), () -> new TestInt(0));
     public static final RegistrySupplier<TestInt> TEST_INT = INTS.register(new ResourceLocation(TestMod.MOD_ID, "test_int"), () -> new TestInt(1));
     public static final RegistrySupplier<TestInt> TEST_INT_2 = INTS.register(new ResourceLocation(TestMod.MOD_ID, "test_int_2"), () -> new TestInt(2));
     
@@ -223,5 +233,8 @@ public class TestRegistries {
         TEST_RECIPE_TYPE.listen(type -> {
             System.out.println("Registered recipe type!");
         });
+        INTS.listen(TEST_INT_2, i -> {
+            System.out.println("Non-existent int: " + INTS.get(new ResourceLocation("non_existent")));
+        });
     }
 }