I am trying to find a way to move items from the player into an opened chest, kind of like a death chest mod but completely client side, so that it will work on servers. What I tried using is this (inside of a keybind):

 

EntityPlayer player = FMLClientHandler.instance().getClient().thePlayer;

player.openContainer.transferStackInSlot(player, 1);

 

This transfers the items in slot one of the chest into the player's inventory when I press the bound key and have a chest open, but once you try to pick up the transferred items, they revert to where they were before. I tried adding this, to see if it would help:

 

player.openContainer.detectAndSendChanges();

player.inventoryContainer.detectAndSendChanges();

 

But those didn't help either. What should I do to get this code to work, or is there another method that will work? Thanks in advance!

completely client side, so that it will work on servers

You got it completely wrong. It is the opposite.

It will never work on server if it is client side.

Use a KeyHandler to send a packet to server side, then move items to the chest.

That may have been a bit unclear. I meant so that I can run it on my client, and it will still work while connected to a server instead of just SSP. Since it has to work on a client while connected to a server, I cant just do something like delete the items in the player inventory and add them in the chest, as the server would not let the client do this.

You can't.  Client side is visual only.

 

If you want something to function like you have described, it would need to be a mod that is installed on the server.

The client has to send the message to the server when it receives the shift click on an item in the inventory. Is there not a way to spoof this and send what ever info to the server that it would send if I had actually gone in and shift clicked a slot myself?

The client has to send the message to the server when it receives the shift click on an item in the inventory. Is there not a way to spoof this and send what ever info to the server that it would send if I had actually gone in and shift clicked a slot myself?

 

Having a container open involves a lot of voodoo.  You can't spoof that.  Opening a chest actually DOES stuff on the server side so the server knows what inventory you're interacting with.