(1.21.4) (Client-side) How do I intercept and modify messages sent by the player?

[D4nPlus6]

Description

Let's say the player types in chat, "The foo is looking nice today!", how do I intercept this message and modify it to replace "foo" with "bar" so that the message that gets sent out is "The bar is looking nice today!" instead?

[modmuss50]

Hey, you can use the ServerMessageDecoratorEvent in the conent phase, see the following example from one of the test mods. This example returns replaces the whole message, but you can just as easily replace or add to the message.

fabric/fabric-message-api-v1/src/testmod/java/net/fabricmc/fabric/test/message/ChatTest.java

Lines 50 to 56 in 6da4c19

	ServerMessageDecoratorEvent.EVENT.register(ServerMessageDecoratorEvent.CONTENT_PHASE, (sender, message) -> {
	if (message.getString().contains("random")) {
	return Text.of(String.valueOf(Random.create().nextBetween(0, 100)));
	}
	return message;
	});

[modmuss50]

Just seen you wanted this for the client side, and not the server. On the client you will want ClientSendMessageEvents.MODIFY_CHAT like so:

fabric/fabric-message-api-v1/src/testmodClient/java/net/fabricmc/fabric/test/message/client/ChatTestClient.java

Lines 54 to 61 in 6da4c19

	ClientSendMessageEvents.MODIFY_CHAT.register((message) -> {
	if (message.contains("modify send")) {
	LOGGER.info("Modifying chat message: " + message);
	return "sending modified chat message";
	}
	return message;
	});

[D4nPlus6]

Thank you so much!

[FlukeBTW]

@Dave-New-Dev did it work as you expected?

[D4nPlus6]

yes :D