CODEWITHSUNDEEP
variablesmoduleluapackageglobal
Zelly
Zelly

Reputation: 19

Lua global variable in module staying nil?

Im starting to learn Lua modules a bit, and I am having troubles with a small part in my Lua. Everytime I change my variable it reverts back to nil.

myModule.lua

--I should note that client is a number.
module(..., package.seeall)
local LoggedIn = { }

function isLogged( client )
    return LoggedIn[client]
end

function logIn(client)
    table.insert(LoggedIn,client,true)
end

function logOut(client)
    table.remove(LoggedIn,client)
end

main.lua an event happens

package.loaded.myModule= nil; require "myModule"

function event( client )
    myModule.logIn(client)
end

function event_2( client )
    myModule.logOut(client)
end

EDIT: Using functions instead, and making it local variable. It is still returning nil even though I can confirm the logIn function happened with no errors. Without even using the logout function yet. Any thoughts?

but later on in main.lua I check if client is logged in and it just returns nil.

Is this just a limitation of modules or am I just accessing the variable wrong.

I should note I need to be able to do this in other Luas that acces myModule.lua too.

Thanks in advance

Upvotes: 1

Views: 3178

Answers (2)

Paul Kulchenko
Paul Kulchenko

Reputation: 26794

The following using your own code (assuming you fix typo in funtion) works (it prints true\nnil):

package.loaded.myModule= nil; require "myModule"
function event( client )
    myModule.LoggedIn[client] = true
end

event("foo")
print(myModule.isLogged("foo"))

A better way to do this would be to add a function logIn as @Mike suggested and avoid using module(); you can use something like this instead:

local myModule = require "myModule"
function event( client )
    myModule.logIn(client)
end

event("foo")
print(myModule.isLogged("foo"))
print(myModule.isLogged("bar"))

And myModule.lua becomes:

local LoggedIn = { }
function isLogged( client )
  return LoggedIn[client]
end
function logIn( client )
  LoggedIn[client] = true
end
return { LoggedIn = LoggedIn, isLogged = isLogged, logIn = logIn }

Upvotes: 1

Mike Corcoran
Mike Corcoran

Reputation: 14564

You don't really give us enough code to fully help you, but this is a working example I set up based on what little example you gave us:

-- myModule.lua
module(..., package.seeall)

LoggedIn = {}

function isLoggedIn(client)
    return LoggedIn[client] ~= nil
end

function LogIn(client)
    LoggedIn[client] = true
end

function LogOut(client)
    LoggedIn[client] = nil
end

and to test it:

-- main.lua
require "myModule"

myModule.LogIn("Joe")
myModule.LogIn("Frank")

print(myModule.isLoggedIn("Bill"))
print(myModule.isLoggedIn("Frank"))

myModule.LogOut("Joe")
print(myModule.isLoggedIn("Joe"))

this prints out as expected:

false
true
false

so my guess is that you are not checking the conditions correctly for LoggedIn[client] being empty, or you never actually remove entries from the LoggedIn table when someone 'logs out'.

Upvotes: 1

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