I'm trying to create a mod that lets me define command aliases in MC. I currently have the following code:

package com.extended_ui.commands;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.io.IOUtils;

import com.mojang.brigadier.Command;
import com.mojang.brigadier.CommandDispatcher;
import com.mojang.brigadier.arguments.StringArgumentType;

import net.minecraft.client.Minecraft;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.commands.Commands;
import net.minecraft.network.chat.Component;

public class Alias {
	private static Map<String, String> aliases = new HashMap<String, String>();

	public static void registerCommands(CommandDispatcher<CommandSourceStack> dispatcher) {
		loadAliasesFromFiles();
		for (Map.Entry<String, String> entry : aliases.entrySet()) {
			registerAlias(dispatcher, entry.getKey(), entry.getValue());
		}

		dispatcher.register(Commands.literal("alias")
			.then(Commands.literal("-l")
				.executes((command) -> { return listAliases(); }))
			.then(Commands.literal("-r")
				.then(Commands.argument("alias", StringArgumentType.word())
					.executes((command) -> { return removeAlias(dispatcher, StringArgumentType.getString(command, "alias")); })))
			.then(Commands.argument("alias", StringArgumentType.word())
				.then(Commands.argument("command", StringArgumentType.greedyString())
					.executes((command) -> { return addAlias(dispatcher, StringArgumentType.getString(command, "alias"), StringArgumentType.getString(command, "command")); })))
		);
	}

	private static int listAliases() {
		Minecraft mc = Minecraft.getInstance();
		for (Map.Entry<String, String> entry : aliases.entrySet()) {
			mc.player.sendSystemMessage(Component.literal(entry.getKey() + ": " + entry.getValue()));
		}
		return Command.SINGLE_SUCCESS;
	}

	private static int addAlias(CommandDispatcher<CommandSourceStack> dispatcher, String alias, String command) {
		// Add alias to the map of aliases
		aliases.put(alias, command);

		// Save alias to file
		try {
			new File("config/aliases").mkdirs();
			Files.write(Paths.get("config/aliases/" + alias), Collections.singletonList(command), StandardCharsets.UTF_8);
		} catch (IOException e) {
			e.printStackTrace();
		}

		// Register new alias in the event dispatcher
		return registerAlias(dispatcher, alias, command);
	}

	private static int registerAlias(CommandDispatcher<CommandSourceStack> dispatcher, String alias, String command) {
		// dispatcher.register(Commands.literal(alias)
		// 	.then(Commands.argument("args", StringArgumentType.greedyString())
		// 		.redirect(command)));
		return Command.SINGLE_SUCCESS;
	}

	private static int removeAlias(CommandDispatcher<CommandSourceStack> dispatcher, String alias) {
		// Remove alias from the map of aliases
		aliases.remove(alias);

		// Remove alias file
		new File("config/aliases/" + alias).delete();

		// Remove alias from the event dispatcher
		// dispatcher.unregister(Commands.literal(alias));  // Not sure the dispatcher supports some way of unregistering commands. If it doesn't, then removing an alias properly will require a game restart
		return Command.SINGLE_SUCCESS;
	}

	private static void loadAliasesFromFiles() {
		File dir = new File("config/aliases");
		if (!(dir.isDirectory()))
			return;
		for (File file : dir.listFiles()) {
			String alias = file.getName();
			try (FileInputStream inputStream = new FileInputStream("foo.txt")) {
				String command = IOUtils.toString(inputStream, StandardCharsets.UTF_8).trim();
				aliases.put(alias, command);
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}

The methods for adding, removing, loading, and listing aliases all work properly (i.e., they add/remove/list the aliases in the aliases Map, and save/remove/load the aliases to/from files). However, right now registering an alias doesn't work, as I can't find a way to register an alias to simply execute the command as if it was sent in the game console. How would I implement the registerAlias method to properly register such a simple forward with the CommandDispatcher?

Edited March 8, 20232 yr by Frozen Storm

I managed to get basic aliases to work using:

private static int registerAlias(CommandDispatcher<CommandSourceStack> dispatcher, String alias, String command) {
	dispatcher.register(Commands.literal(alias)
		.executes((commandContext) -> {
			dispatcher.execute(command, commandContext.getSource());
			return Command.SINGLE_SUCCESS;
		})
	);
}

 

I also managed to add the possibility for arguments in the alias, and my entire method looks like this now:

private static int registerAlias(CommandDispatcher<CommandSourceStack> dispatcher, String alias, String command) {
	Pattern argPattern = Pattern.compile("\\$\\{?(\\d+)}?");
	if (argPattern.matcher(command).find()) {
		dispatcher.register(Commands.literal(alias)
			.then(Commands.argument("args", StringArgumentType.greedyString())
				.executes((commandContext) -> {
					String commandString = command;
					String argString = StringArgumentType.getString(commandContext, "args");
					String[] args = ArgumentTokenizer.tokenize(argString).toArray(new String[0]);
					commandString = argPattern.matcher(commandString).replaceAll(
						match -> args[Integer.parseInt(match.group(1))-1]
					);
					dispatcher.execute(commandString, commandContext.getSource());
					return Command.SINGLE_SUCCESS;
				}))
		);
	} else {
		dispatcher.register(Commands.literal(alias)
			.executes((commandContext) -> {
				dispatcher.execute(command, commandContext.getSource());
				return Command.SINGLE_SUCCESS;
			})
		);
	}
	return Command.SINGLE_SUCCESS;
}

This way if a command contains any $1, $2, $10, ${1}, etc., it gets registered as an alias with arguments, otherwise it gets registered as a standalone. ArgumentTokenizer is the class I found here.

Edited March 2, 20232 yr by Frozen Storm
Different question for different thread