Cookbook:Adding New RCon Commands

Problem

You want to create your own RCon command(s) to add administrative features to BF2. You really don't want to change the code for standard BF2 administration module, though, because you know modifying the standard code is a Bad Idea™.

Solution

Use the dynamic object modification technique explained in the Cookbook:Changing_Objects_At_Runtime Changing Objects At Runtime recipie. Just import the following function from one of the main modules:

 import new, default
 
 def registerRConCommand(command, function):
     '''Register a custom RCon command by dynamically adding a function that
      implements the new command as a new method of the default.AdminServer class.
      Parameters: command = a string that gives the name of the new RCon command
                  function = a function that implements the command.'''
    
     # Put the function into a new instancemethod object bound to the AdminServer
     newMethod = new.instancemethod(function, default.server, default.AdminServer)
    
     # Create a new class attribute in AdminServer that's wired to our function
     setattr(default.AdminServer, command, newMethod)
    
     # Add the new command into the rcon dispatch table, pointing to our function
     default.server.rcon_cmds[command] = newMethod

registerRConCommand takes care of everything you need to do to create a new RCon command; to use it, you just need to define the Python function you want your new RCon command to execute, and then call registerRConCommand to register your new command and link it to your function:

 # Create a function that executes our desired new RCon command; note that since
 # this is going to be a method within a class, the first argument to the
 # function MUST be "self", even if we don't use it. The admin module also
 # passes "ctx" (command context) and "cmd" (the rest of the RCon command line)
 # to our function.
 def rcmd_mycmd(self, ctx, cmd):
     # We can make our new command do anything we want here
     ctx.write("We're now executing mycmd.\n")
 
 # Now register the new RCon command
 registerRConCommand('mycmd', rcmd_mycmd)

After this code is imported, your new RCon command will be active; once you authenticate (rcon login <password>) you can execute your command from the server console, or an in-game player console, by typing:

 rcon mycmd 

If you want to execute it from an RCon TCP connection, you just need to type mycmd (without the "rcon").

Discussion

You can add as many commands as you want, each of which can implement any function you want--and they will behave exactly as though they were coded in the Battlefield 2 Server/admin/default.py file--even though you never had to change that file!

The reason this is so useful, and the reason why it's such a bad idea to just hack around with the standard files, is that doing so makes it very difficult to upgrade to a new version of BF2 later, plus, if you have multiple mods or add-ons that want to add their own RCon commands, they will very quickly start tripping over and breaking each other if they're all modifying the original code. This approach is much cleaner; in fact, you can have multiple scripts like this that are all developed separately by different people, but when they're imported, they behave gracefully with each other, with no problem at all (unless two developers choose identical names for their new commands).

Submitted By

--Woody