Hi !

I'm creating a small GUI mod to edit some item stats, like it's name, lore, enchantments etc...

The GUI opens if the player has an item in his main hand.

But now I'm in trouble with using the NBT system to change an ItemStack's name.

After pressing a "Done" button, in the

actionPerformed(GuiButton button)

, this is what I did :

 

if (button == this.doneButton) { // If it's the correct button
if(itemStack.getTagCompound() == null) // If the itemstack doesn't have a TagCompound...
	itemStack.setTagCompound(new NBTTagCompound()); // ...I'll create an empty one
[color=red]itemStack.getTagCompound().getCompoundTag("tag").getCompoundTag("display").setString("Name", name.getText()); // This is where I'm wrong ('name' is the GuiTextField I'm using)[/color]
Minecraft.getMinecraft().thePlayer.openGui(ItemEditorMod.instance, ItemEditorGuiHandler.ITEM_EDITOR_MENU, Minecraft.getMinecraft().theWorld, // This is the method to go to the previous GuiScreen
(int) Minecraft.getMinecraft().thePlayer.posX, (int) Minecraft.getMinecraft().thePlayer.posY,
(int) Minecraft.getMinecraft().thePlayer.posZ);
} 

 

When I check the NBT tag of the selected item using NBTExplorer, no new compound appears. Can someone help me ?

 

 

When I check the NBT tag of the selected item using NBTExplorer, no new compound appears. Can someone help me ?

 

This is because you've edited the client-side object, and as soon as you open the player's inventory again, the server's version overwrites your changes.  You need to send a packet to the server and make the change there.

Alright, then I'll learn how does Networking work. Thanks.

Its easy.

https://mcforge.readthedocs.io/en/latest/networking/simpleimpl/

Ok, so my Network setup is working. Thanks to Draco18s for his link and diesieben07 for his tutorial (http://www.minecraftforge.net/forum/index.php?topic=20135.0). This is in my Message Handler class :

@Override
public IMessage onMessage(final EditItemMessage message, final MessageContext ctx) {
IThreadListener mainThread = (WorldServer) ctx.getServerHandler().playerEntity.worldObj;
        mainThread.addScheduledTask(new Runnable() {
                @Override
                public void run() {
                	System.out.println("New Name : " + message.text);
                	// Help
                }
        });
        return null;
}

I know I can get the ItemStack I want by using

ctx.getServerHandler().playerEntity.getHeldItemMainhand()

, but then I don't know what to do. I just want to change the ItemStack's name using NBT.

Well, didn't you say that it wasn't good ? Because if I do the same same thing...

if(ctx.getServerHandler().playerEntity.getHeldItemMainhand().getTagCompound() == null) ctx.getServerHandler().playerEntity.getHeldItemMainhand().setTagCompound(new NBTTagCompound());
ctx.getServerHandler().playerEntity.getHeldItemMainhand().getTagCompound().getCompoundTag("tag").getCompoundTag("display").setString("Name", message.text);

...I'm getting the same object with an empty "tag" Tag Compound.

I have a

stack.getSubCompound()

method, but no

stack.getOrCreateSubCompound()

method. And of course when I use the first one I get a NullPointerException.

ItemStack#getOrCreateSubCompound

has the SRG name

func_190925_c

, so that's probably the method name you'll need to use.

 

I suggest you update your MCP mappings so this is deobfuscated for you.

You're right ! Thanks a lot, now it works !