Allow to set custom intermediary url again (#528)

* allow to set custom intermediary url again

* apply suggestions

* add some javadoc

src/main/java/net/fabricmc/loom/LoomGradleExtension.java

@@ -99,8 +99,7 @@ public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 	}
 
 	default String getIntermediaryUrl(String minecraftVersion) {
-		// TODO reimplement a way to change this, was never really supported api anyway
-		return String.format("https://maven.fabricmc.net/net/fabricmc/intermediary/%1$s/intermediary-%1$s-v2.jar", minecraftVersion);
+		return String.format(this.getIntermediaryUrl().get(), minecraftVersion);
 	}
 
 	@Override

src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java

@@ -211,4 +211,11 @@ public interface LoomGradleExtensionAPI {
 	 * @return the property controlling the transitive access wideners
 	 */
 	Property<Boolean> getEnableTransitiveAccessWideners();
+
+	/**
+	 * Use "%1$s" as a placeholder for the minecraft version.
+	 *
+	 * @return the intermediary url template
+	 */
+	Property<String> getIntermediaryUrl();
 }

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java

@@ -61,6 +61,7 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 	protected final Property<String> customManifest;
 	protected final Property<Boolean> setupRemappedVariants;
 	protected final Property<Boolean> transitiveAccessWideners;
+	protected final Property<String> intermediary;
 
 	private final ModVersionParser versionParser;
 
@@ -85,6 +86,8 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 		this.transitiveAccessWideners = project.getObjects().property(Boolean.class)
 				.convention(true);
 		this.transitiveAccessWideners.finalizeValueOnRead();
+		this.intermediary = project.getObjects().property(String.class)
+				.convention("https://maven.fabricmc.net/net/fabricmc/intermediary/%1$s/intermediary-%1$s-v2.jar");
 
 		this.versionParser = new ModVersionParser(project);
 
@@ -173,6 +176,11 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	protected abstract LoomFiles getFiles();
 
+	@Override
+	public Property<String> getIntermediaryUrl() {
+		return intermediary;
+	}
+
 	@Override
 	public void disableDeprecatedPomGeneration(MavenPublication publication) {
 		net.fabricmc.loom.configuration.MavenPublication.excludePublication(publication);

src/main/java/net/fabricmc/loom/extension/MinecraftGradleExtension.java

@@ -156,4 +156,10 @@ public class MinecraftGradleExtension implements LoomGradleExtensionAPI {
 		reportDeprecation();
 		throw new UnsupportedOperationException();
 	}
+
+	@Override
+	public Property<String> getIntermediaryUrl() {
+		reportDeprecation();
+		return parent.getIntermediaryUrl();
+	}
 }