Issues replacing content of a component

[kangarko]

In calling TextComponent#content(String) it appears to ignore the new content.

Context: I am using ProtocolLib and listening to ClientboundSystemChatPacket which has two fields, content and adventure$content. My goal is to edit these fields before the packet gets sent.

Before adventure, this was simple. Now I am trying to get the adventure$content field which works, but after setting its new content it appears not to work anymore.

The relevant code excerpt is here. Please note that the system.out prints out "ClientboundSystemChatPacket -> set to: " as if the new content is still empty even after it has been set.

Using Paper build 510.

[Machine-Maker]

Components are immutable. Calling adventureContent.content(message) doesn't mutate adventureContent, it just returns a new component with that content.

[kangarko]

So how can I modify the content of the ClientboundSystemChatPacket?

[kezz]

Well, this is Adventure support not Java support. Changing a final field is up to you, all I can tell you is how components work.

[kangarko]

I understand and I appreciate the fast support. All I needed was a way to connect to Adventure using the packet which Paper has edited to use your library. I've opened a ticket at ProtocolLib.

Afaik it looks unsolvable as long as either Paper doesn't remove the final modifier from the field or you don't add that change in your implementation.

[kangarko]

Discussed in PaperMC/Paper#9128

[kezz]

We won't change anything our side - we already have mutable components in the form of component builders. Whatever other implementations/users of our library do is up to them.

[kangarko]

I understand, that is correct and I respect that is out of your bounds. Thanks so far.

[Greazi-Times]

Altho this librarry could be used. Protocollib has a working option.
The changes in 1.19 make it that you need to use Reflection. This isn't possible with java 8

There for there needs to be made a work around to get this working.
I have to take a look again how this needs to be done but this is the best shot on fixing this issue.

[zml2008]

The changes in 1.19 make it that you need to use Reflection. This isn't possible with java 8

what?

1. reflection is nothing new
2. this doesn't stop you from doing a different strategy, like having your packet manipulation system replace one packet instance with another one that you construct yourself

this is a fairly common design pattern, there are loads of ways to handle changing one element nested in an immutable object graph.

[Greazi-Times]

Well we have a system that changes messages send to a player.
With 1.19 it got changed and there for it din't work.

We have added a check for 1.19 and lower if thats true its using the old way.
But once its 1.19 or higher it is using a whole other system.

This systeem takes a lot of information about the message as thats now needed to make it work.

[kangarko]

Thanks guys, I was able to recreate the packet and fixed it! kangarko/Foundation@8374209