feat: DisplayTest in mods.toml

mdk/src/main/resources/META-INF/mods.toml

@@ -32,6 +32,14 @@ logoFile="examplemod.png" #optional
 credits="Thanks for this example mod goes to Java" #optional
 # A text field displayed in the mod UI
 authors="Love, Cheese and small house plants" #optional
+# Display Test controls the display for your mod in the server connection screen
+# MATCH_VERSION means that your mod will cause a red X if the versions on client and server differ. This is the default behaviour and should be what you choose if you have server and client elements to your mod.
+# IGNORE_SERVER_VERSION means that your mod will not cause a red X if it's present on the server but not on the client. This is what you should use if you're a server only mod.
+# IGNORE_ALL_VERSION means that your mod will not cause a red X if it's present on the client or the server. This is a special case and should only be used if your mod has no server component.
+# NONE means that no display test is set on your mod. You need to do this yourself, see IExtensionPoint.DisplayTest for more information. You can define any scheme you wish with this value.
+# IMPORTANT NOTE: this is NOT an instruction as to which environments (CLIENT or DEDICATED SERVER) your mod loads on. Your mod should load (and maybe do nothing!) whereever it finds itself.
+#displayTest="MATCH_VERSION" # MATCH_VERSION is the default if nothing is specified (#optional)
+
 # The description text for the mod (multi line!) (#mandatory)
 description='''
 This is a long form description of the mod. You can write whatever you want here

src/main/java/net/minecraftforge/fml/ModContainer.java

@@ -8,6 +8,8 @@
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.fml.config.ModConfig;
 import net.minecraftforge.fml.event.lifecycle.IModBusEvent;
+import net.minecraftforge.fml.network.FMLNetworkConstants;
+import net.minecraftforge.forgespi.language.IConfigurable;
 import net.minecraftforge.forgespi.language.IModInfo;
 import org.apache.commons.lang3.tuple.Pair;
 
@@ -20,6 +22,7 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.function.BiFunction;
+import java.util.function.BiPredicate;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -56,9 +59,37 @@ public ModContainer(IModInfo info)
         this.namespace = this.modId;
         this.modInfo = info;
         this.modLoadingStage = ModLoadingStage.CONSTRUCT;
-        // default displaytest extension checks for version string match
-        registerExtensionPoint(ExtensionPoint.DISPLAYTEST, () -> Pair.of(()->this.modInfo.getVersion().toString(),
-                (incoming, isNetwork)->Objects.equals(incoming, this.modInfo.getVersion().toString())));
+
+        // SPI doesn't give config
+        IConfigurable configurable = (IConfigurable) info;
+        final String displayTestOption = configurable.<String>getConfigElement("displayTest").orElse("MATCH_VERSION"); // missing defaults to DEFAULT type
+        Supplier<Pair<Supplier<String>, BiPredicate<String, Boolean>>> displayTest;
+        switch (displayTestOption) {
+            case "MATCH_VERSION": // default displaytest checks for version string match
+                displayTest = () -> Pair.of(() -> this.modInfo.getVersion().toString(),
+                        (incoming, isNetwork) -> Objects.equals(incoming, this.modInfo.getVersion().toString()));
+                break;
+
+            case "IGNORE_SERVER_VERSION": // Ignores any version information coming from the server - use for server only
+                displayTest = () -> Pair.of(() -> FMLNetworkConstants.IGNORESERVERONLY, (incoming, isNetwork) -> true);
+                break;
+
+            case "IGNORE_ALL_VERSION": // Ignores all information and provides no information
+                displayTest = () -> Pair.of(() -> "", (incoming, isNetwork) -> true);
+                break;
+
+            case "NONE":// NO display test at all - use this if you're going to do your own display test
+                displayTest = null;
+                break;
+
+            default:// any other value throws an exception
+                throw new IllegalArgumentException("Invalid displayTest value supplied in mods.toml");
+        }
+
+        if (displayTest != null)
+            registerExtensionPoint(ExtensionPoint.DISPLAYTEST, displayTest);
+        else
+            extensionPoints.remove(ExtensionPoint.DISPLAYTEST);
     }
 
     /**