I have a mod that can run on the client independent of whether it is installed on a server.  What I want to do is fine tune client side behavior of my mod if it happens to be installed on the remote server.  Is there a client side query I can make to ask if my mod is installed remotely, or do I need to do something more passive like assume its not installed until I get evidence that it is installed (like a network packet coming in)?

 

(I could just go the passive route and make it work regardless, but right now this is point of my education.  I may learn something. )

I don't think you do need to send a packet here.

 

You can create a method in your

@Mod

class that takes

(Map<String, String>, Side)

as arguments and returns a

boolean

and then annotate it with

@NetworkCheckHandler

. This will be called when connecting to the remote client/server to check if the mods on that side are acceptable.

 

The

Map<String, String>

arguments contains the mods on the remote side, with mod ID keys and mod version values. The

Side

argument is the remote side, so it will be

SERVER

if the method is being called on the logical client or

CLIENT

if the method is being called on the logical server.

 

Return

true

to accept the connection or

false

to reject it.

 

You can check if your mod ID is in the

Map

(i.e. if your mod is on the remote side) and then store this as a

boolean

somewhere to use it outside this method.

 

JEI does this here and here.

That is interesting.  I will have to take a look at that.  Unfortunately, though, my nefarious plan hit a snag.  I will go the passive route.  Main reason is that I introduced an option to disable a feature server side meaning that the Client can't rely on the fact the the mod is installed remotely to behave a certain way.  I could do a handshake to transfer necessary bits and what not, but the passive route, at least for my mod, is the least complex and easiest way.

No, it's easy.

 

When the client connects to the server, the server side of your code sends a packet to that client.

 

If the server side isn't installed guess what.