LibRPC Examples

The new version of LibRPC (of this article) is about to be released

New functions Fa, RFCa was added to library for raw calling of functions with a specified environment class or instance. Earlier the 'this' was always the roottable. By using "compilestring", one do not need Fa and RFCa.

The Problem

F("MyFunction")(p1, p2, ... )

On serverside, it is equivalent to

MyFunction(p1, p2,... )

Considering environments this is equal to :

MyFunction.call(getroottable(), p1, p2, ... )

Suppose i want to call

MyFunction.call(m, p1, p2, ... )

where m is a table other than roottable. How to do it?

It is for this reason that new function Fa (different from F) is introduced.

The Working

Suppose i want to call

MyFunction.call(m, p1, p2, ... )

where m is any table and rest are parameters(integers, strings, etc) and the case is 'MyFunction' resides in roottable. The following leads to error:

Fa("MyFunction")(m, p1, p2, ... )

because the key MyFunction will be looked inside table m. So if MyFunction is in roottable, the correct code will be

Fa(F("rawget")("MyFunction"))(m, p1, p2, ... )

When the first order parameter in Fa is not "string" but userdata (i.e not "MyFunction", but return value of F), then it will call the function(first order parameter) with second order parameters where the first of the second order parameter as environment.

Example One

Let us see an example. Suppose that in roottable of server a table 'C' exists which has a slot named 'a' whose value is 3. Now we are printing that value on server console from npc ( npc must be admin to print. Not only print, but actually for executing any functions remotely ). On serverside, what we want is

print(C.rawget("a"))

Corresponding remote function call would be

RFC("print")( Fa("rawget")( F("rawget")("C"), "a" ) )

Note: F will rawget from roottable while Fa will rawget from its first parameter. F("rawget")("C") will return the table C.

Example Two - Kicking the player

Calling FindPlayer(0).Kick remotely requires

RFCa("Kick")(F("FindPlayer")(0))

Here RFCa ( parallel of RFC, as Fa is to F ) looks for key 'Kick' after pushing it's first 2nd order parameter ( FindPlayer(0) ). Alternatively, you can use this too using KickPlayer

RFC("KickPlayer")(F("FindPlayer")(0))

Example Three: Tough One - Setting the Cash

How will you do this:

FindPlayer(0).Cash=2000

?

To understand this, let us see how the 'Cash' function is stored.

print(CPlayer.__setTable.Cash)
[SCRIPT]  (function : 0x033A4CC8)

and

CPlayer.__setTable.Cash.call(FindPlayer(0),2001)
print(FindPlayer(0).Cash)
[SCRIPT]  2001

So we got what we wanted: CPlayer.__setTable.Cash.call(instance, cash ) The corresponding remote code would be (tested):

RFCa(Fa("rawget")(Fa("rawget")(F("rawget")("CPlayer"),"__setTable"),"Cash"))(F("FindPlayer
")(0),2000)

Explanation( 3 step ):
1. The innermost 'F' is used to rawget "CPlayer" from roottable
2. The inner Fa is used to rawget '__setTable' from class CPlayer.
3. The outer Fa is used to rawget function 'Cash' from table __setTable.
4. The outer RFCa means we are raw calling. So The Cash function obtained in (3) is called with instance FindPlayer(0) as first parameter and cash amount: 2000 as second parameter

Other Examples

Remark	Serverside	npc-side
a is a global variable	a=100;	RFC("rawset")("a", 100)
Setting npc's weapon	FindPlayer( npcid ).SetWeapon(33, 900)	RFCa("SetWeapon")(F("FindPlayer")(GetMyID()), 33, 900) or RFCa(Fa("rawget")(F("rawget")("CPlayer"),"SetWeapon"))(F("FindPlayer")(0),32, 900)
Setting player's vehicle	FindPlayer( 0 ).Vehicle = FindVehicle( 5 ) This can be called: CPlayer.__setTable.Vehicle.call( FindPlayer(0), FindVehicle(5) )	The code will be: func<-Fa("rawget")(Fa("rawget")(F("rawget")("CPlayer"),"__setTable"),"Vehicle"); RFCa(func)(F("FindPlayer")(0), F("FindVehicle")(5)) The above code can be broken down to: local myclass=F("rawget")("CPlayer"); local mytable=Fa("rawget")(myclass, "__setTable"); local func=Fa("rawget")(mytable, "Vehicle" ); RFCa(func)(F("FindPlayer")(0),F("FindVehicle")(5))

Notes

1. The functions of CPlayer class like SetWeapon, SetAnim, SetWantedLevel can be called directly (As in second row of table).
2. The 'property' functions - 'Vehicle', 'Cash', 'Pos', etc are hidden in the __setTable (of CPlayer class) for setting the value and __getTable (") for getting the value. (Third row example illustrates this)
3. The npc04relxx plugin which executes the codes in server given from npc only if npc is made admin in server.