[1.9] Executing a Client command when client joins a server

[TommyHoogstra]

Hey everyone, I'm kinda new to forge but have a fair amount of java experience, I'm in a bit of a rush so I was hoping of someone could give me some pointers as google hasnt satisfied my needs.

 

I'm trying to get the client to run a command as soon as it joins a server, e.g. /auth 123111717

 

I've tried using the ClientConnectToServer (forgot its exact name, forgive me), EntityJoinWorldEvent, PlayerLoggedInEvent (i think this is for server side mods, excuse me if I'm wrong) but have had no such luck at getting a command to execute.

 

Any pointers, or examples?

 

Thanks

[Choonster]

FMLNetworkEvent.ClientConnectedToServerEvent

or

EntityJoinWorldEvent

should work, though there's something to note about each event:

• All sub-events of

  FMLNetworkEvent

  are fired on the Netty thread, so you need to schedule a task on the main thread using

  IThreadListener

  before you can safely interact with normal Minecraft classes. This is explained in slightly more detail here.
  

• EntityJoinWorldEvent

  will be fired for every entity that joins the world and will also be fired when the player respawns or changes dimension.
  

 

PlayerLoggedInEvent

is only fired server-side, so it can't be used by a client-only mod in multiplayer (it will work in single player because the integrated server is running in the same JVM process as the client).

 

Use

ICommandManager#executeCommand

to execute a command. The

ICommandManager

for client commands is stored in the

ClientCommandHandler.instance

field.

[TommyHoogstra]

For the EntityJoinWorldEvent, couldn't I just check if the entity is instanceof EntityPlayerSP?

[Choonster]

For the EntityJoinWorldEvent, couldn't I just check if the entity is instanceof EntityPlayerSP?

 

Yes, that should work.

[TommyHoogstra]

Ok, So I went with the ClientConnectedToServerEvent, and even though I haven't added the command to my server yet, I was expecting an 'unknown command' message to pop up.

 

Am I missing something?

 

@Mod(modid = "MAH", version = "1.0")
public class MAH {

@EventHandler
public void init(FMLInitializationEvent e){

	MinecraftForge.EVENT_BUS.register(new Events());
}

@EventHandler
public void postInit(FMLPostInitializationEvent event)
{
}

@EventHandler
public void preInit(FMLPreInitializationEvent event)
{
}

 

public class Events {

@SubscribeEvent
public void onJoin(ClientConnectedToServerEvent event) {

	Minecraft.getMinecraft().addScheduledTask(new Auth());

}
}

 

public class Auth implements Runnable {

@Override
public void run() {
	ClientCommandHandler.instance.executeCommand(Minecraft.getMinecraft().thePlayer, "/auth");

}

}

[Choonster]

The FML bus has been merged with the Forge bus now, so

FMLCommonHandler#bus

is deprecated; though it will still work since it returns a reference to the Forge bus.

 

If the command doesn't exist,

ClientCommandHandler#executeCommand

will return 0; it won't throw an exception or send a chat message.

 

Is this command supposed to be handled on the client or the server? If it's a server command, you need to send a chat message packet to the server with the command in it.

[TommyHoogstra]

Its a server command, is there any documentation on the Chat Message Packet, or an example around?

 

Thanks

[Choonster]

Use

EntityPlayerSP#sendChatMessage

to send a chat message packet to the server.

[TommyHoogstra]

Ok, thanks very much.

 

However, this is all that needed to change in my code, but it still doesn't  send the command when I join, I think im missing something obvious, but I'm new Forge and its API so I'm not quite sure.

 

 

public class Auth implements Runnable {

@Override
public void run() {

	Minecraft.getMinecraft().thePlayer.sendChatMessage("/auth");

}

}

[Choonster]

That should work, since it's the same method used by the chat GUI to send chat messages to the server. Does it work if you send some text that isn't a slash command?

[TommyHoogstra]

It doesn't seem to be working without the slash either

 

I also tried addChatMessage, that didnt work either.

I'm assuming its something wrong with the scheduled task?

[TommyHoogstra]

That should work, since it's the same method used by the chat GUI to send chat messages to the server. Does it work if you send some text that isn't a slash command?

 

Sorry for double post, i can confirm it works with EntityJoinWorldEvent, however, I would like to find out if theres a way to check the 'join' cause, e.g. Respawning, Logging in, etc.

 

Right now im just using a boolean that gets set to false if the client logs out, and true when the entity joins.

[Choonster]

It turns out that

FMLNetworkEvent.ClientConnectedToServerEvent

is fired before the client player is created and the server has finished the handshake process, so you can't use

Minecraft#thePlayer

or send packets.

 

What you can do is have a separate event handler for

EntityJoinWorldEvent

that you register from the

FMLNetworkEvent.ClientConnectedToServerEvent

handler. When the client player joins the world, send the chat message and then unregister the event handler.

 

I've written an example of this here.

[TommyHoogstra]

Thanks very much!