Player = nil in module script. Why?

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#1

I am trying to pass the player into a module script to send some information to my server.

I am using a server script, and passing information into a ‘server’ module.
When I pass the player into the parameters, the player is nil on the other side (the server module)

Server Script:

local serverMods = require(game:GetService("ServerScriptService").Modules.ServerModules)
print (player, player.Name) -- prints my players name
local result = serverMods:SavePlayerLeaderStats(player, stage, timeLaps);

Module Script:

function module.SavePlayerLeaderStats(player, stage, completionTime)	
print (player, player.Name) -- prints nil
end

I’ve tried doing some basic debugging, and searched the forums/google for a similar issue, but found no answers so far. I’d thought of just sending the player name, rather than the player; but I’d like to omit unnecessary extra code if possible, and I like to know why things don’t work :slight_smile:

What could the issue be?

Thank you for reading
Regards!

1 Like
#2

It’s because you cannot define the local player in server scripts(including module scripts)

#3

Actually, I disagree.

To keep this simple, I’d say a module script acts like the script that requires the module. If only LocalScripts are requiring the module, having the local player as a variable or defining it would be fine. On the other hand that would error when attempting to require the module with a ServerScript.

#4

Thank you for replying
The server script does not send localPlayer; player is gathered this way:

touchPart.Touched:Connect(function(hit)
	
	local player =  game.Players:FindFirstChild(hit.Parent.Name);
	if player ~= nil then 
-- do some stuff
end
end)

Thank you for replying.

A single module containing both server and client commands will work regardless of where the module is being called (Server or local scripts); its the code contained in the module that would be conflicting. That said, obviously, server modules would be stored on the serverscriptservice, as to avoid exploiting; and thus no local script could call it anyway. That is, if you care about the content within your script being secret.

#5

How are you calling that module function? Are you using . or :?

5 Likes
#6

I was using :

Replacing it with ‘.’ has solved my issue. But I don’t understand why.

#7

The reason you were having this problem is because using : is “syntactic sugar”. Under the hood, using a colon injects the table itself as the first argument.

For instance:

myModule:Test(32) is exactly the same as myModule.Test(myModule, 32)

As such, defining a function on a table can be written like this:

function myModule:Test(num) is the same as function myModule.Test(self, num). In that first example, self is injected as the first argument implicitly.

8 Likes
#8

Is that how OOP works? (I’m very interested in learning in OOP). Could you explain the difference between using : or . in creating functions?

EDIT: I’ve read many many topics on OOP but never understood them.

#9

Check out this thread: All about Object Oriented Programming

4 Likes
#10

Yes and no. Lua does not have actual OOP, but you can come close enough using metatables. Lua does not normally have a self or this keyword, so : was added to cover the missing functionality. As @Crazyman32 said, : calls the function with the table as the first argument. Using metatables, we can create class functions like you would in other languages.

local class = {}
class.__index = class
-- if you want this class to get the functions from another class, add this next line
-- setmetatable(class, inheritanceclass)

function class:doSomething()
  -- self is now defined
  self.foo = "bar"
end

function class.new()
  local newobject = {}
  setmetatable(newobject, class) -- now if we call a function on the new object, it will look for __index in the metatable, find it pointing to class, then look through class for the function
  return newobject
end

local object = class.new()
object:doSomething()
print(object.foo) --> bar
3 Likes