Table of Contents
Command Redirects
Redirects are Brigadier's form of aliases and subcommands. The redirect
method takes a command node and an optional modifier of context. The command node can be a specific node after a registration of dispathcer, or just the root node.
Aliases
In vanilla Minecraft, /tell
and /w
are redirected to /msg
, which you can see in MessageCommand
.
The example shows how /foo2
redirects to /foo
.
public class ExampleMod implements ModInitializer { @Override public void onInitialize() { CommandRegistrationCallback.EVENT.register((dispatcher, registryAccess, environment) -> { final LiteralCommandNode<ServerCommandSource> fooNode = dispatcher.register(literal("foo") .executes(context -> { // For versions below 1.19, replace "Text.literal" with "new LiteralText". context.getSource().sendMessage(Text.literal("Called /foo with no arguments")); return 1; })); dispatcher.register(literal("foo2").redirect(fooNode)); }); } }
The redirect
tells brigadier to continue parsing the command at another command node.
Chainable Commands
Commands such as /execute as @e[type=player] in the_end run tp ~ ~ ~
are also possible because of redirects.
Let's first consider the vanilla /execute
command. There is a node after the literal("execute")
. After dispatching subcommands, the dispatcher is redirected to that node (with some modifiers), making you possible to, after completing sub-command arguments, type whatever can be typed directly after /execute
. In the sub-command run
, the dispatcher is redirected to the root node (dispatcher.getRoot()
), allowing you to type another complete command after the word “run
”.
Below is an example of a chainable command:
LiteralCommandNode<ServerCommandSource> rootNode = dispatcher.register(literal("fabric_test")); LiteralCommandNode<ServerCommandSource> root1 = dispatcher.register(literal("fabric_test") // You can register under the same literal more than once, it will just register new parts // of the branch as shown below if you register a duplicate branch an error will popup in // console warning of conflicting commands but one will still work. .then(literal("extra") .then(literal("long") .redirect(rootNode, this::lengthen)) // Return to root for chaining .then(literal("short") .redirect(rootNode, this::shorten))) // Return to root for chaining .then(literal("command") .executes(ctx -> { ctx.getSource().sendFeedback(Text.literal("Chainable Command"), false); return Command.SINGLE_SUCCESS; })));
The redirect
can also modify the CommandSource
by use of a “redirect modifier” (SingleRedirectModifier<S>
), which is used as a lambda.
.redirect(rootNode, context -> { // When redirecting, modify the looking direction of the command source. return ((ServerCommandSource) context.getSource()).withLookingAt(Vec3ArgumentType.getVec3(context, "pos")); })