Simplify extension point system (#80)

loader/src/main/java/net/neoforged/fml/IExtensionPoint.java

@@ -13,19 +13,10 @@
  *
  * <p>An extension point can be registered for a mod container using {@link ModContainer#registerExtensionPoint(Class, Supplier)}
  * and retrieved (if present) using {@link ModContainer#getCustomExtension(Class)}. An extension point allows a mod to
- * supply an arbitrary value as a record class to another mod or framework through their mod container class, avoiding
+ * supply an arbitrary value to another mod or framework through their mod container class, avoiding
  * the use of {@link InterModComms} or other external frameworks to pass around these values.</p>
- *
- * <p>The usual way to declare an extension point is to implement this interface on a record class, with the type
- * parameter being a reference to the class itself. For example, {@code record MyExtension(...) extends
- * IExtensionPoint<MyExtension>} would declare an extension point which supplies a {@code MyExtension} object. However,
- * there is no hard requirement that an extension point's type parameter must be in reference to itself; the type
- * parameter may reference another record class instead.</p>
- *
- * @param <T> the type of the record which is held by the extension point
  */
-@SuppressWarnings("unused") // Type parameter T
-public interface IExtensionPoint<T extends Record>
+public interface IExtensionPoint
 {
     /**
      * Extension point for the compatibility display test used on the server selection screen.
@@ -93,7 +84,7 @@ public interface IExtensionPoint<T extends Record>
      * @see net.neoforged.client.ForgeHooksClient#processForgeListPingData(net.minecraft.network.protocol.status.ServerStatus, net.minecraft.client.multiplayer.ServerData)
      */
     @SuppressWarnings("JavadocReference") // reference to NetworkConstants, ForgeHooksClient
-    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint<DisplayTest> {
+    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint {
         public static final String IGNORESERVERONLY = "OHNOES\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31";
     }
 }

loader/src/main/java/net/neoforged/fml/ModContainer.java

@@ -54,7 +54,7 @@ public abstract class ModContainer
     protected ModLoadingStage modLoadingStage;
     protected Supplier<?> contextExtension;
     protected final Map<ModLoadingStage, Runnable> activityMap = new HashMap<>();
-    protected final Map<Class<? extends IExtensionPoint<?>>, Supplier<?>> extensionPoints = new IdentityHashMap<>();
+    protected final Map<Class<? extends IExtensionPoint>, Supplier<?>> extensionPoints = new IdentityHashMap<>();
     protected final EnumMap<ModConfig.Type, ModConfig> configs = new EnumMap<>(ModConfig.Type.class);
 
     public ModContainer(IModInfo info)
@@ -66,20 +66,20 @@ public ModContainer(IModInfo info)
         this.modLoadingStage = ModLoadingStage.CONSTRUCT;
 
         final String displayTestString = info.getConfig().<String>getConfigElement("displayTest").orElse("MATCH_VERSION"); // missing defaults to DEFAULT type
-        Supplier<IExtensionPoint.DisplayTest> displayTestSupplier = switch (displayTestString) {
+        var displayTest = switch (displayTestString) {
             case "MATCH_VERSION" -> // default displaytest checks for version string match
-                    () -> new IExtensionPoint.DisplayTest(() -> this.modInfo.getVersion().toString(),
+                    new IExtensionPoint.DisplayTest(() -> this.modInfo.getVersion().toString(),
                         (incoming, isNetwork) -> Objects.equals(incoming, this.modInfo.getVersion().toString()));
             case "IGNORE_SERVER_VERSION" -> // Ignores any version information coming from the server - use for server only mods
-                    () -> new IExtensionPoint.DisplayTest(() -> IExtensionPoint.DisplayTest.IGNORESERVERONLY, (incoming, isNetwork) -> true);
+                    new IExtensionPoint.DisplayTest(() -> IExtensionPoint.DisplayTest.IGNORESERVERONLY, (incoming, isNetwork) -> true);
             case "IGNORE_ALL_VERSION" -> // Ignores all information and provides no information
-                    () -> new IExtensionPoint.DisplayTest(() -> "", (incoming, isNetwork) -> true);
+                    new IExtensionPoint.DisplayTest(() -> "", (incoming, isNetwork) -> true);
             case "NONE" -> null; // NO display test at all - use this if you're going to do your own display test
             default -> // any other value throws an exception
                     throw new IllegalArgumentException("Invalid displayTest value supplied in mods.toml");
         };
-        if (displayTestSupplier != null)
-            registerExtensionPoint(IExtensionPoint.DisplayTest.class, displayTestSupplier);
+        if (displayTest != null)
+            registerExtensionPoint(IExtensionPoint.DisplayTest.class, displayTest);
         else
             extensionPoints.remove(IExtensionPoint.DisplayTest.class);
     }
@@ -143,12 +143,22 @@ public IModInfo getModInfo()
     }
 
     @SuppressWarnings("unchecked")
-    public <T extends Record> Optional<T> getCustomExtension(Class<? extends IExtensionPoint<T>> point) {
+    public <T extends IExtensionPoint> Optional<T> getCustomExtension(Class<T> point) {
         return Optional.ofNullable((T)extensionPoints.getOrDefault(point,()-> null).get());
     }
 
-    public <T extends Record & IExtensionPoint<T>> void registerExtensionPoint(Class<? extends IExtensionPoint<T>> point, Supplier<T> extension)
-    {
+    /**
+     * Registers an {@link IExtensionPoint} with the mod container.
+     */
+    public <T extends IExtensionPoint> void registerExtensionPoint(Class<T> point, T extension) {
+        extensionPoints.put(point, () -> extension);
+    }
+
+    /**
+     * Registers an {@link IExtensionPoint} with the mod container.
+     * This overload allows passing a supplier that will only be evaluated when the extension is requested.
+     */
+    public <T extends IExtensionPoint> void registerExtensionPoint(Class<T> point, Supplier<T> extension) {
         extensionPoints.put(point, extension);
     }
 

loader/src/main/java/net/neoforged/fml/ModLoadingContext.java

@@ -44,7 +44,7 @@ public String getActiveNamespace() {
      * @param extension An extension operator
      * @param <T> The type signature of the extension operator
      */
-    public <T extends Record & IExtensionPoint<T>> void registerExtensionPoint(Class<? extends IExtensionPoint<T>> point, Supplier<T> extension) {
+    public <T extends IExtensionPoint> void registerExtensionPoint(Class<T> point, Supplier<T> extension) {
         getActiveContainer().registerExtensionPoint(point, extension);
     }