[1.7.2] Modifying NBT on client-side

[Pardeep]

I'm making a mod where, at the core, I want to edit custom variables of a player through a button on a gui, opened from right-clicking a block.

The only problem is in the GUI class there's no way to get the modification to happen on the server side (as far as I know).

Is there a way I can either:

1) Send a client->server packet for NBT, because as far as I know there isn't a PacketHandler method for sending to the server AND specifying which player gets it.

OR

2) Some way of changing the variables on the server side within the GUI, perhaps through other classes.

 

All help is appreciated. Thanks in advance.

[Pardeep]

You will need to send Packets.

If you send a packet to the server, the server will know who send it and match it to the correct player.

So I tried your advice and it didn't work. The NBT data does not seem to be updating on the server side. Is there no way I can change the variable on the server side in the GUI?